@misc{WessigJohnSperlichetal.2020, author = {Wessig, Pablo and John, Leonard and Sperlich, Eric and Kelling, Alexandra}, title = {Sulfur tuning of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {3}, issn = {1866-8372}, doi = {10.25932/publishup-56624}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-566241}, pages = {15}, year = {2020}, abstract = {The replacement of oxygen by sulfur atoms of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes is an efficient way to adjust the photophysical properties (sulfur tuning). While previously developed S-4-DBD dyes exhibit considerably red-shifted absorption and emission wavelength, the heavy atom effect of four sulfur atoms cause low fluorescence quantum yields and short fluorescence lifetimes. Herein, we demonstrate that the replacement of less than four sulfur atoms (S-1-DBD, 1,2-S-2-DBD, and 1,4-S-2-DBD dyes) permits a fine-tuning of the photophysical properties. In some cases, a similar influence on the wavelength without the detrimental effect on the quantum yields and lifetimes is observed. Furthermore, the synthetic accessibility of S-1- and S-2-DBD dyes is improved, compared with S-4-DBD dyes. For coupling with biomolecules a series of reactive derivatives of the new dyes were developed (azides, OSu esters, alkynes, maleimides).}, language = {en} } @article{StraussWangDelacroixetal.2020, author = {Strauss, Volker and Wang, Huize and Delacroix, Simon and Ledendecker, Marc and Wessig, Pablo}, title = {Carbon nanodots revised}, series = {Chemical science}, volume = {11}, journal = {Chemical science}, number = {31}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2041-6520}, doi = {10.1039/d0sc01605e}, pages = {8256 -- 8266}, year = {2020}, abstract = {Luminescent compounds obtained from the thermal reaction of citric acid and urea have been studied and utilized in different applications in the past few years. The identified reaction products range from carbon nitrides over graphitic carbon to distinct molecular fluorophores. On the other hand, the solid, non-fluorescent reaction product produced at higher temperatures has been found to be a valuable precursor for the CO2-laser-assisted carbonization reaction in carbon laser-patterning. This work addresses the question of structural identification of both, the fluorescent and non-fluorescent reaction products obtained in the thermal reaction of citric acid and urea. The reaction products produced during autoclave-microwave reactions in the melt were thoroughly investigated as a function of the reaction temperature and the reaction products were subsequently separated by a series of solvent extractions and column chromatography. The evolution of a green molecular fluorophore, namely HPPT, was confirmed and a full characterization study on its structure and photophysical properties was conducted. The additional blue fluorescence is attributed to oligomeric ureas, which was confirmed by complementary optical and structural characterization. These two components form strong hydrogen-bond networks which eventually react to form solid, semi-crystalline particles with a size of similar to 7 nm and an elemental composition of 46\% C, 22\% N, and 29\% O. The structural features and properties of all three main components were investigated in a comprehensive characterization study.}, language = {en} } @article{WessigBadetkoCzarneckietal.2022, author = {Wessig, Pablo and Badetko, Dominik and Czarnecki, Maciej and Wichterich, Lukas and Schmidt, Peter and Brudy, Cosima and Sperlich, Eric and Kelling, Alexandra}, title = {Studies toward the total synthesis of arylnaphthalene lignans via a Photo-Dehydro-Diels-Alder (PDDA) reaction}, series = {The journal of organic chemistry}, volume = {87}, journal = {The journal of organic chemistry}, number = {9}, publisher = {American Chemical Society}, address = {Washington}, issn = {0022-3263}, doi = {10.1021/acs.joc.2c00195}, pages = {5904 -- 5915}, year = {2022}, abstract = {An efficient method for the preparation of arylnaphthalene lignans (ANLs) was developed, which is based on thePhoto-Dehydro-DIELS-ALDER(PDDA) reaction. While intermolecular PDDA reactions turned out to be inefficient, theintramolecular variant using suberic acid as tether linking two aryl propiolic esters smoothly provided naphthalenophanes. Theirradiations were performed with a previously developed annular continuous-flow reactor and UVB lamps. In this way, the naturalproducts Alashinol D, Taiwanin C, and an unnamed ANL could be prepared.}, language = {en} } @article{HaubitzJohnFreyseetal.2020, author = {Haubitz, Toni and John, Leonard and Freyse, Daniel and Wessig, Pablo and Kumke, Michael Uwe}, title = {Investigating the Sulfur "Twist" on the Photophysics of DBD Dyes}, series = {The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment \& general theory}, volume = {124}, journal = {The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment \& general theory}, number = {22}, publisher = {American Chemical Society}, address = {Washington}, issn = {1089-5639}, doi = {10.1021/acs.jpca.0c01880}, pages = {4345 -- 4353}, year = {2020}, abstract = {The so-called DBD ([1,3]dioxolo[4,5-f][1,3]benzodioxole) dyes are a new class of fluorescent dyes, with tunable photophysical properties like absorption, fluorescence lifetime, and Stokes shift. With the development of sulfur based DBDs, this dye class is extended even further for possible applications in spectroscopy and microscopy. In this paper we are investigating the basic photophysical properties and their implications for future applications for S-4-DBD as well as O-4-DBD. On the basis of time-resolved laser fluorescence spectroscopy, transient absorption spectroscopy, and UV/vis-spectroscopy, we determined the rate constants of the radiative and nonradiative deactivation processes as well as the energy of respective electronic states involved in the electronic deactivation of S-4-DBD and of O-4-DBD. For S-4-DBD we unraveled the triplet formation with intersystem crossing quantum yields of up to 80\%. By TD-DFT calculations we estimated a triplet energy of around 13500-14700 cm(-1) depending on the DBD dye and solvent. Through solvent dependent measurements, we found quadrupole moments in the range of 2 B.}, language = {en} } @article{WessigFreyseSchusteretal.2020, author = {Wessig, Pablo and Freyse, Daniel and Schuster, David and Kelling, Alexandra}, title = {Fluorescent dyes with large stokes shifts based on Benzo[1,2-d:4,5-d']bis([1,3]dithiole) ("S4-DBD Dyes")}, series = {Europan journal of organic chemistry}, volume = {2020}, journal = {Europan journal of organic chemistry}, number = {11}, publisher = {Wiley}, address = {Weinheim}, issn = {1434-193X}, doi = {10.1002/ejoc.202000093}, pages = {1732 -- 1744}, year = {2020}, abstract = {We report on a further development of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes by replacement of the four oxygen atoms of the heterocyclic core by sulfur atoms. This variation causes striking changes of the photophysical properties. Whereas absorption and emission significantly shifted to longer wavelength, the fluorescence lifetimes and quantum yields are diminished compared to DBD dyes. The latter effect is presumably caused by an enhanced intersystem crossing to the triplet state due to the sulfur atoms. The very large Stokes shifts of the S-4-DBD dyes ranging from 3000 cm(-1) to 7400 cm(-1) (67 nm to 191 nm) should be especially emphasized. By analogy with DBD dyes a broad variation of absorption and emission wavelength is possible by introducing different electron withdrawing substituents. Moreover, some derivatives for coupling with biomolecules were developed.}, language = {en} } @article{WessigJohnSperlichetal.2020, author = {Wessig, Pablo and John, Leonard and Sperlich, Eric and Kelling, Alexandra}, title = {Sulfur tuning of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes}, series = {European journal of organic chemistry}, volume = {2021}, journal = {European journal of organic chemistry}, number = {3}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-193X}, doi = {10.1002/ejoc.202001418}, pages = {499 -- 511}, year = {2020}, abstract = {The replacement of oxygen by sulfur atoms of [1,3]-dioxolo[4.5-f]benzodioxole (DBD) fluorescent dyes is an efficient way to adjust the photophysical properties (sulfur tuning). While previously developed S-4-DBD dyes exhibit considerably red-shifted absorption and emission wavelength, the heavy atom effect of four sulfur atoms cause low fluorescence quantum yields and short fluorescence lifetimes. Herein, we demonstrate that the replacement of less than four sulfur atoms (S-1-DBD, 1,2-S-2-DBD, and 1,4-S-2-DBD dyes) permits a fine-tuning of the photophysical properties. In some cases, a similar influence on the wavelength without the detrimental effect on the quantum yields and lifetimes is observed. Furthermore, the synthetic accessibility of S-1- and S-2-DBD dyes is improved, compared with S-4-DBD dyes. For coupling with biomolecules a series of reactive derivatives of the new dyes were developed (azides, OSu esters, alkynes, maleimides).}, language = {en} } @article{WessigKrebs2021, author = {Wessig, Pablo and Krebs, Saskia}, title = {N-aroylsulfonamide-photofragmentation (ASAP)}, series = {European journal of organic chemistry}, volume = {2021}, journal = {European journal of organic chemistry}, number = {46}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-193X}, doi = {10.1002/ejoc.202100955}, pages = {6367 -- 6374}, year = {2021}, abstract = {The photochemical fragmentation of N-aroylsulfonamides 9 (ASAP) is a powerful method for the preparation of various biaryls. Compounds 9 are easily accessible in two steps from amines by treatment with arenesulfonyl chlorides and aroyl chlorides. Many of these compounds were prepared for the first time. The irradiation takes place in a previously developed continuous-flow reactor using inexpensive UVB or UVC fluorescent lamps. Isocyanates and sulphur dioxide are formed as the only by-products. The ASAP tolerates a variety of functional groups and is even suited for the preparation of phenylnaphthalenes and terphenyls. The ASAP mechanism was elucidated by interaction of photophysical and quantum chemical (DFT) methods and revealed a spirocyclic biradical as key intermediate.}, language = {en} } @article{MeynersMertensWessigetal.2017, author = {Meyners, Christian and Mertens, Monique and Wessig, Pablo and Meyer-Almes, Franz-Josef}, title = {A Fluorescence-Lifetime-Based Binding Assay for Class IIa Histone Deacetylases}, series = {Chemistry - a European journal}, volume = {23}, journal = {Chemistry - a European journal}, number = {13}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0947-6539}, doi = {10.1002/chem.201605140}, pages = {3107 -- 3116}, year = {2017}, abstract = {Class IIa histone deacetylases (HDACs) show extremely low enzymatic activity and no commonly accepted endogenous substrate is known today. Increasing evidence suggests that these enzymes exert their effect rather through molecular recognition of acetylated proteins and recruiting other proteins like HDAC3 to the desired target location. Accordingly, class IIa HDACs like bromodomains have been suggested to act as "Readers" of acetyl marks, whereas enzymatically active HDACs of class I or IIb are called "Erasers" to highlight their capability to remove acetyl groups from acetylated histones or other proteins. Small-molecule ligands of class IIa histone deacetylases (HDACs) have gained tremendous attention during the last decade and have been suggested as pharmaceutical targets in several indication areas such as cancer, Huntington's disease and muscular atrophy. Up to now, only enzyme activity assays with artificial chemically activated trifluoroacetylated substrates are in use for the identification and characterization of new active compounds against class IIa HDACs. Here, we describe the first binding assay for this class of HDAC enzymes that involves a simple mix-and-measure procedure and an extraordinarily robust fluorescence lifetime readout based on [1,3]dioxolo[4,5-f]benzodioxole-based ligand probes. The principle of the assay is generic and can also be transferred to class I HDAC8.}, language = {en} } @article{WessigJohnMertens2018, author = {Wessig, Pablo and John, Leonard and Mertens, Monique}, title = {Extending the Class of [1,3]-Dioxolo[4.5-f]benzodioxole (DBD) Fluorescent Dyes}, series = {European journal of organic chemistry}, volume = {2018}, journal = {European journal of organic chemistry}, number = {14}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-193X}, doi = {10.1002/ejoc.201800002}, pages = {1674 -- 1681}, year = {2018}, abstract = {Synthetic routes to a collection of new fluorescent dyes are described, which are based on the [1,3]-dioxolo[4.5-f]benzodioxole (DBD) core. By introducing different electron withdrawing groups in 4- and 8-position of the DBD moiety the emission wavelength could be adjusted over a large spectral range from blue to orange light.}, language = {en} } @article{MertensHilschHaralampievetal.2018, author = {Mertens, Monique and Hilsch, Malte and Haralampiev, Ivan and Volkmer, Rudolf and Wessig, Pablo and M{\"u}ller, Peter}, title = {Synthesis and characterization of a new Bifunctionalized, Fluorescent, and Amphiphilic molecule for recruiting SH-Containing molecules to membranes}, series = {ChemBioChem}, volume = {19}, journal = {ChemBioChem}, number = {15}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1439-4227}, doi = {10.1002/cbic.201800268}, pages = {1643 -- 1647}, year = {2018}, abstract = {This study describes the synthesis and characterization of an amphiphilic construct intended to recruit SH-containing molecules to membranes. The construct consists of 1)an aliphatic chain to enable anchoring within membranes, 2)a maleimide moiety to react with the sulfhydryl group of a soluble (bio)molecule, and 3)a fluorescence moiety to allow the construct to be followed by fluorescence spectroscopy and microscopy. It is shown that the construct can be incorporated into preformed membranes, thus allowing application of the approach with biological membranes. The close proximity between the fluorophore and the maleimide moiety within the construct causes fluorescence quenching. This allows monitoring of the reaction with SH-containing molecules by measurement of increases in fluorescence intensity and lifetime. Notably, the construct distributes into laterally ordered membrane domains of lipid vesicles, which is probably triggered by the length of its membrane anchor. The advantages of the new construct can be employed for several biological, biotechnological, and medicinal applications.}, language = {en} } @article{BuechnerJohnMertensetal.2018, author = {B{\"u}chner, D{\"o}rthe and John, Leonard and Mertens, Monique and Wessig, Pablo}, title = {Detection of dsDNA with [1,3]Dioxolo[4,5-f]benzodioxol (DBD) Dyes}, series = {Chemistry - a European journal}, volume = {24}, journal = {Chemistry - a European journal}, number = {60}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0947-6539}, doi = {10.1002/chem.201804057}, pages = {16183 -- 16190}, year = {2018}, abstract = {DBD fluorescent dyes have proven to be useful in numerous applications. To widen the range of biological applications, we propose three different types of DBD molecules that have been modified in such a way that DNA interaction becomes probable. After the successful synthesis of all three compounds, we tested their fluorescent properties and their DNA binding abilities. Two of the three probes exhibit an interaction with dsDNA with subsequent fluorescence enhancement. The determined binding constants of the two new DNA dyes are comparable to other minorgroove-binding dyes. Their large Stokes shifts and their long fluorescent lifetimes are outstanding features of these dyes.}, language = {en} } @article{LopezdeGuerenuBastianWessigetal.2019, author = {L{\´o}pez de Guere{\~n}u, Anna and Bastian, Philipp and Wessig, Pablo and John, Leonard and Kumke, Michael Uwe}, title = {Energy Transfer between Tm-Doped Upconverting Nanoparticles and a Small Organic Dye with Large Stokes Shift}, series = {Biosensors : open access journal}, volume = {9}, journal = {Biosensors : open access journal}, number = {1}, publisher = {MDPI}, address = {Basel}, issn = {2079-6374}, doi = {10.3390/bios9010009}, pages = {17}, year = {2019}, abstract = {Lanthanide-doped upconverting nanoparticles (UCNP) are being extensively studied for bioapplications due to their unique photoluminescence properties and low toxicity. Interest in RET applications involving UCNP is also increasing, but due to factors such as large sizes, ion emission distributions within the particles, and complicated energy transfer processes within the UCNP, there are still many questions to be answered. In this study, four types of core and core-shell NaYF4-based UCNP co-doped with Yb3+ and Tm3+ as sensitizer and activator, respectively, were investigated as donors for the Methyl 5-(8-decanoylbenzo[1,2-d:4,5-d ']bis([1,3]dioxole)-4-yl)-5-oxopentanoate (DBD-6) dye. The possibility of resonance energy transfer (RET) between UCNP and the DBD-6 attached to their surface was demonstrated based on the comparison of luminescence intensities, band ratios, and decay kinetics. The architecture of UCNP influenced both the luminescence properties and the energy transfer to the dye: UCNP with an inert shell were the brightest, but their RET efficiency was the lowest (17\%). Nanoparticles with Tm3+ only in the shell have revealed the highest RET efficiencies (up to 51\%) despite the compromised luminescence due to surface quenching.}, language = {en} } @misc{SchwarzeRiemerMuelleretal.2019, author = {Schwarze, Thomas and Riemer, Janine and M{\"u}ller, Holger and John, Leonard and Holdt, Hans-J{\"u}rgen and Wessig, Pablo}, title = {Na+ Selective Fluorescent Tools Based on Fluorescence Intensity Enhancements, Lifetime Changes, and on a Ratiometric Response}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1136}, issn = {1866-8372}, doi = {10.25932/publishup-43748}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-437482}, pages = {13}, year = {2019}, abstract = {Over the years, we developed highly selective fluorescent probes for K+ in water, which show K+-induced fluorescence intensity enhancements, lifetime changes, or a ratiometric behavior at two emission wavelengths (cf. Scheme 1, K1-K4). In this paper, we introduce selective fluorescent probes for Na+ in water, which also show Na+ induced signal changes, which are analyzed by diverse fluorescence techniques. Initially, we synthesized the fluorescent probes 2, 4, 5, 6 and 10 for a fluorescence analysis by intensity enhancements at one wavelength by varying the Na+ responsive ionophore unit and the fluorophore moiety to adjust different K-d values for an intra- or extracellular Na+ analysis. Thus, we found that 2, 4 and 5 are Na+ selective fluorescent tools, which are able to measure physiologically important Na+ levels at wavelengths higher than 500 nm. Secondly, we developed the fluorescent probes 7 and 8 to analyze precise Na+ levels by fluorescence lifetime changes. Herein, only 8 (K-d=106 mm) is a capable fluorescent tool to measure Na+ levels in blood samples by lifetime changes. Finally, the fluorescent probe 9 was designed to show a Na+ induced ratiometric fluorescence behavior at two emission wavelengths. As desired, 9 (K-d=78 mm) showed a ratiometric fluorescence response towards Na+ ions and is a suitable tool to measure physiologically relevant Na+ levels by the intensity change of two emission wavelengths at 404 nm and 492 nm.}, language = {en} } @article{RiemerShipmanWessigetal.2019, author = {Riemer, Nastja and Shipman, Michael and Wessig, Pablo and Schmidt, Bernd}, title = {Iterative arylation of itaconimides with diazonium salts through electrophilic palladium catalysis}, series = {The journal of organic chemistry}, volume = {84}, journal = {The journal of organic chemistry}, number = {9}, publisher = {American Chemical Society}, address = {Washington}, issn = {0022-3263}, doi = {10.1021/acs.joc.9b00627}, pages = {5732 -- 5746}, year = {2019}, abstract = {N-Arylitaconimides, accessible from maleic anhydride, anilines, and paraformaldehyde, react with arene diazonium salts in Pd-catalyzed Matsuda-Heck arylation to the pharmacologically relevant E-configured 3-arylmethylidene pyrrolidine-2,5-diones (also known as arylmethylidene succinimides) through exo-selective beta-H-elimination. The coupling proceeds at ambient temperature with the simple and easy-to-handle precatalyst Pd-II-acetate under ligandand base-free conditions. Notable features are high isolated yields, regio- and stereoselectivities, and short reaction times. In a comparative investigation, aryl iodides, bromides, and triflates were shown to be inferior coupling reagents in this reaction. The 3-arylmethylidene pyrrolidine-2,5-diones undergo second Matsuda-Heck coupling, which proceeds via endo-selective beta-H-elimination to give diarylmethyl-substituted maleimides as coupling products. These products can also be accessed in one flask by sequential addition of different arene diazonium salts to the starting itaconimide. The potential of 3-arylmethylidene succinimides as photoswitches was tested. Upon irradiation of the E-isomer at 300 nm, partial isomerization to the Z-isomer (E/Z = 65:35 in the photostationary state) was observed. The isomerization was found to be nearly completely reversible by irradiating the mixture at 400 nm.}, language = {en} } @article{HaubitzJohnWessigetal.2019, author = {Haubitz, Toni and John, Leonard and Wessig, Pablo and Kumke, Michael Uwe}, title = {Photophysics of Acyl- and Ester-DBD Dyes}, series = {the journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment \& general theory}, volume = {123}, journal = {the journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment \& general theory}, number = {22}, publisher = {American Chemical Society}, address = {Washington}, issn = {1089-5639}, doi = {10.1021/acs.jpca.9b02973}, pages = {4717 -- 4726}, year = {2019}, abstract = {A new generation of wavelength-tunable, fluorescent dyes, so-called DBD ([1,3]dioxolo[4,5-f][1,3]benzodioxole) dyes, were developed a few years ago, and they showed great potential as probes, for example, for fluorescence microscopy. However, their photophysics is not fully explored and leaves open questions regarding their large fluorescence Stokes shifts and sensitivity to solvent conditions of differently substituted DBD dyes. To improve the understanding of the influence of the substitution pattern of the DBD dyes on their respective photophysics, transient absorption spectroscopy (TAS) was used, that is, a pump-probe experiment on the femtosecond timescale. TAS allows measurements of excited states, ground state recovery, solvent relaxation, and fluorescence properties on time scales of up to several nanoseconds. Two different DBD dye samples were investigated: aryl- and ester-substituted DBD dyes. Experiments were carried out in solvents with different polarities using different excitation energies and at different viscosities. Based on the experimental data and theoretical calculations, we were able to determine the conformational changes of the molecule due to electronic excitation and were able to investigate solvent relaxation processes for both types of DBD dyes. By generalizing the theory for quadrupole-induced solvent relaxation developed by Togashi et al., we derived quadrupole moments of both molecules in the ground and excited state. Our data showed differences in the binding of polar solvent molecules to the dyes depending on the substituent on the DBD dye. In the case of water as the solvent, an additional efficient quenching process in the electronically excited state was revealed, which was indicated by the observation of solvated electrons in the TAS signals.}, language = {en} } @article{CzarneckiWessig2018, author = {Czarnecki, Maciej and Wessig, Pablo}, title = {Scaling Up UV-Mediated Intramolecular Photodehydro-Diels-Alder Reactions Using a Homemade High-Performance Annular Continuous-Flow Reactor}, series = {Organic Process Research \& Development}, volume = {22}, journal = {Organic Process Research \& Development}, number = {12}, publisher = {American Chemical Society}, address = {Washington}, issn = {1083-6160}, doi = {10.1021/acs.oprd.8b00353}, pages = {1823 -- 1827}, year = {2018}, abstract = {Here we present a self-made annular continuous-flow reactor that can be used in the UV/vis range in an internal numbering-up manner. As a model reaction, we chose a powerful batch-scale-limited benzoannelation method, namely, an intramolecular photodehydro-Diels-Alder (IMPDDA) reaction. The scale-up potential of this particular photochemical benchmark reaction toward the preparation of macrocylic (1,7)naphthalenophanes by variation of selected flow parameters is presented.}, language = {en} } @article{HoangMertensWessigetal.2018, author = {Hoang, Hoa T. and Mertens, Monique and Wessig, Pablo and Sellrie, Frank and Schenk, J{\"o}rg A. and Kumke, Michael Uwe}, title = {Antibody Binding at the Liposome-Water Interface}, series = {ACS Omega}, volume = {3}, journal = {ACS Omega}, number = {12}, publisher = {American Chemical Society}, address = {Washington}, issn = {2470-1343}, doi = {10.1021/acsomega.8b03016}, pages = {18109 -- 18116}, year = {2018}, abstract = {Different signal amplification strategies to improve the detection sensitivity of immunoassays have been applied which utilize enzymatic reactions, nanomaterials, or liposomes. The latter are very attractive materials for signal amplification because liposomes can be loaded with a large amount of signaling molecules, leading to a high sensitivity. In addition, liposomes can be used as a cell-like "bioscaffold" to directly test recognition schemes aiming at cell-related processes. This study demonstrates an easy and fast approach to link the novel hydrophobic optical probe based on [1,3]dioxolo[4,5-f]-[1,3]benzodioxole (DBD dye mm239) with tunable optical properties to hydrophilic recognition elements (e.g., antibodies) using liposomes for signal amplification and as carrier of the hydrophobic dye. The fluorescence properties of mm239 (e.g., long fluorescence lifetime, large Stokes shift, high photostability, and high quantum yield), its high hydrophobicity for efficient anchoring in liposomes, and a maleimide bioreactive group were applied in a unique combination to build a concept for the coupling of antibodies or other protein markers to liposomes (coupling to membranes can be envisaged). The concept further allowed us to avoid multiple dye labeling of the antibody. Here, anti-TAMRA-antibody (DC7-Ab) was attached to the liposomes. In proof-of-concept, steady-state as well as time-resolved fluorescence measurements (e.g., fluorescence depolarization) in combination with single molecule detection (fluorescence correlation spectroscopy, FCS) were used to analyze the binding interaction between DC7-Ab and liposomes as well as the binding of the antigen rhodamine 6G (R6G) to the antibody. Here, the Forster resonance energy transfer (FRET) between mm239 and R6G was monitored. In addition to ensemble FRET data, single-molecule FRET (PIE-FRET) experiments using pulsed interleaved excitation were used to characterize in detail the binding on a single-molecule level to avoid averaging out effects.}, language = {en} } @misc{WessigMatthes2013, author = {Wessig, Pablo and Matthes, Annika}, title = {Photochemical synthesis and properties of 1,6- and 1,8-Naphthalenophanes}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1042}, issn = {1866-8372}, doi = {10.25932/publishup-47667}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-476675}, pages = {13}, year = {2013}, abstract = {Various 1,6- and 1,8-naphthalenophanes were synthesized by using the Photo-Dehydro-Diels-Alder (PDDA) reaction of bis-ynones. These compounds are easily accessible from omega-(3-iodophenyl)carboxylic acids in three steps. The obtained naphthalenophanes are axially chiral and the activation barrier for the atropisomerization could be determined in some cases by means of dynamic NMR (DNMR) and/or dynamic HPLC (DHPLC) experiments.}, language = {en} } @article{SchwarzeRiemerMuelleretal.2019, author = {Schwarze, Thomas and Riemer, Janine and M{\"u}ller, Holger and John, Leonard and Holdt, Hans-J{\"u}rgen and Wessig, Pablo}, title = {Na+ Selective Fluorescent Tools Based on Fluorescence Intensity Enhancements, Lifetime Changes, and on a Ratiometric Response}, series = {Chemistry - a European journal}, volume = {25}, journal = {Chemistry - a European journal}, number = {53}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0947-6539}, doi = {10.1002/chem.201902536}, pages = {12412 -- 12422}, year = {2019}, abstract = {Over the years, we developed highly selective fluorescent probes for K+ in water, which show K+-induced fluorescence intensity enhancements, lifetime changes, or a ratiometric behavior at two emission wavelengths (cf. Scheme 1, K1-K4). In this paper, we introduce selective fluorescent probes for Na+ in water, which also show Na+ induced signal changes, which are analyzed by diverse fluorescence techniques. Initially, we synthesized the fluorescent probes 2, 4, 5, 6 and 10 for a fluorescence analysis by intensity enhancements at one wavelength by varying the Na+ responsive ionophore unit and the fluorophore moiety to adjust different K-d values for an intra- or extracellular Na+ analysis. Thus, we found that 2, 4 and 5 are Na+ selective fluorescent tools, which are able to measure physiologically important Na+ levels at wavelengths higher than 500 nm. Secondly, we developed the fluorescent probes 7 and 8 to analyze precise Na+ levels by fluorescence lifetime changes. Herein, only 8 (K-d=106 mm) is a capable fluorescent tool to measure Na+ levels in blood samples by lifetime changes. Finally, the fluorescent probe 9 was designed to show a Na+ induced ratiometric fluorescence behavior at two emission wavelengths. As desired, 9 (K-d=78 mm) showed a ratiometric fluorescence response towards Na+ ions and is a suitable tool to measure physiologically relevant Na+ levels by the intensity change of two emission wavelengths at 404 nm and 492 nm.}, language = {en} } @misc{LopezdeGuerenuBastianWessigetal.2019, author = {L{\´o}pez de Guere{\~n}u, Anna and Bastian, Philipp and Wessig, Pablo and John, Leonard and Kumke, Michael Uwe}, title = {Energy transfer between tm-doped upconverting nanoparticles and a small organic dye with large stokes shift}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, number = {961}, issn = {1866-8372}, doi = {10.25932/publishup-47224}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-472240}, pages = {19}, year = {2019}, abstract = {Lanthanide-doped upconverting nanoparticles (UCNP) are being extensively studied for bioapplications due to their unique photoluminescence properties and low toxicity. Interest in RET applications involving UCNP is also increasing, but due to factors such as large sizes, ion emission distributions within the particles, and complicated energy transfer processes within the UCNP, there are still many questions to be answered. In this study, four types of core and core-shell NaYF4-based UCNP co-doped with Yb3+ and Tm3+ as sensitizer and activator, respectively, were investigated as donors for the Methyl 5-(8-decanoylbenzo[1,2-d:4,5-d ']bis([1,3]dioxole)-4-yl)-5-oxopentanoate (DBD-6) dye. The possibility of resonance energy transfer (RET) between UCNP and the DBD-6 attached to their surface was demonstrated based on the comparison of luminescence intensities, band ratios, and decay kinetics. The architecture of UCNP influenced both the luminescence properties and the energy transfer to the dye: UCNP with an inert shell were the brightest, but their RET efficiency was the lowest (17\%). Nanoparticles with Tm3+ only in the shell have revealed the highest RET efficiencies (up to 51\%) despite the compromised luminescence due to surface quenching.}, language = {en} } @article{WessigSchulzePfennigetal.2017, author = {Wessig, Pablo and Schulze, Tanja and Pfennig, Alexandra and Weidner, Steffen M. and Prentzel, Sascha and Schlaad, Helmut}, title = {Thiol-ene polymerization of oligospiroketal rods}, series = {Polymer Chemistry}, volume = {8}, journal = {Polymer Chemistry}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1759-9954}, doi = {10.1039/c7py01569k}, pages = {6879 -- 6885}, year = {2017}, abstract = {The nucleophilic thiol-ene (thia-Michael) reaction between molecular rods bearing terminal thiols and bis-maleimides was investigated. The molecular rods have oligospiroketal (OSK) and oligospirothioketal (OSTK) backbones. Contrary to the expectations, cyclic oligomers were always obtained instead of linear rigid-rod polymers. Replacing the OS(T)K rods with a flexible chain yielded polymeric products, suggesting that the OS(T) K structure is responsible for the formation of cyclic products. The reason for the preferred formation of cyclic products is due to the presence of folded conformations, which have already been described for articulated rods.}, language = {en} } @article{SchwarzeMertensMuelleretal.2017, author = {Schwarze, Thomas and Mertens, Monique and Mueller, Peter and Riemer, Janine and Wessig, Pablo and Holdt, Hans-J{\"u}rgen}, title = {Highly K+-Selective Fluorescent Probes for Lifetime Sensing of K+ in Living Cells}, series = {Chemistry - a European journal}, volume = {23}, journal = {Chemistry - a European journal}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0947-6539}, doi = {10.1002/chem.201704368}, pages = {17186 -- 17190}, year = {2017}, abstract = {The new K+-selective fluorescent probes 1 and 2 were obtained by Cu-I-catalyzed 1,3-dipolar azide alkyne cycloaddition (CuAAC) reactions of an alkyne-substituted [1,3]dioxolo[4,5-f][1,3]benzodioxole (DBD) ester fluorophore with azido-functionalized N-phenylaza-18-crown-6 ether and N-(o-isopropoxy) phenylaza-18-crown-6 ether, respectively. Probes 1 and 2 allow the detection of K+ in the presence of Na+ in water by fluorescence enhancement (2.2 for 1 at 2000mm K+ and 2.5 for 2 at 160mm K+). Fluorescence lifetime measurements in the absence and presence of K+ revealed bi-exponential decay kinetics with similar lifetimes, however with different proportions changing the averaged fluorescence decay times ((f(av))). For 1 a decrease of (f(av)) from 12.4 to 9.3ns and for 2 an increase from 17.8 to 21.8ns was observed. Variation of the substituent in ortho position of the aniline unit of the N-phenylaza-18-crown-6 host permits the modulation of the K-d value for a certain K+ concentration. For example, substitution of H in 1 by the isopropoxy group (2) decreased the K-d value from >300mm to 10mm. 2 was chosen for studying the efflux of K+ from human red blood cells (RBC). Upon addition of the Ca2+ ionophor ionomycin to a RBC suspension in a buffer containing Ca2+, the fluorescence of 2 slightly rose within 10min, however, after 120min a significant increase was observed.}, language = {en} } @article{KlaperWessigLinker2016, author = {Klaper, Matthias and Wessig, Pablo and Linker, Torsten}, title = {Base catalysed decomposition of anthracene endoperoxide}, series = {Chemical communications}, volume = {52}, journal = {Chemical communications}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1359-7345}, doi = {10.1039/c5cc08606j}, pages = {1210 -- 1213}, year = {2016}, abstract = {Catalytic amounts of a weak base are sufficient to induce the decomposition of anthracene endoperoxides to anthraquinone. The mechanism has been elucidated by isolation of intermediates in combination with DFT calculations. The whole process is suitable for the convenient generation of hydrogen peroxide under very mild conditions.}, language = {en} } @article{BaderKlierHettrichetal.2016, author = {Bader, Denise and Klier, Dennis Tobias and Hettrich, C. and Bier, Frank Fabian and Wessig, Pablo}, title = {Detecting carbohydrate-lectin interactions using a fluorescent probe based on DBD dyes}, series = {Analytical methods : advancing methods and applications}, volume = {8}, journal = {Analytical methods : advancing methods and applications}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1759-9660}, doi = {10.1039/c5ay02991k}, pages = {1235 -- 1238}, year = {2016}, abstract = {Herein we present an efficient synthesis of a biomimetic probe with modular construction that can be specifically bound by the mannose binding FimH protein - a surface adhesion protein of E. coli bacteria. The synthesis combines the new and interesting DBD dye with the carbohydrate ligand mannose via a Click reaction. We demonstrate the binding to E. coli bacteria over a large concentration range and also present some special characteristics of those molecules that are of particular interest for the application as a biosensor. In particular, the mix-and-measure ability and the very good photo-stability should be highlighted here.}, language = {en} } @article{WessigBehrendsKumkeetal.2016, author = {Wessig, Pablo and Behrends, Nicole and Kumke, Michael Uwe and Eisold, Ursula and Meiling, Til and Hille, Carsten}, title = {Two-photon FRET pairs based on coumarin and DBD dyes}, series = {RSC Advances}, volume = {6}, journal = {RSC Advances}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2046-2069}, doi = {10.1039/c6ra03983a}, pages = {33510 -- 33513}, year = {2016}, abstract = {The synthesis and photophysical properties of two new FRET pairs based on coumarin as a donor and DBD dye as an acceptor are described. The introduction of a bromo atom dramatically increases the two-photon excitation (2PE) cross section providing a 2PE-FRET system, which is also suitable for 2PE-FLIM.}, language = {en} } @article{WessigGerngrossFreyseetal.2016, author = {Wessig, Pablo and Gerngross, Maik and Freyse, Daniel and Bruhn, P. and Przezdziak, Marc and Schilde, Uwe and Kelling, Alexandra}, title = {Molecular Rods Based on Oligo-spiro-thioketals}, series = {The journal of organic chemistry}, volume = {81}, journal = {The journal of organic chemistry}, publisher = {American Chemical Society}, address = {Washington}, issn = {0022-3263}, doi = {10.1021/acs.joc.5b02670}, pages = {1125 -- 1136}, year = {2016}, abstract = {We report on an extension of the previously established concept of oligospiroketal (OSK) rods by replacing a part or all ketal moieties by thioketals leading to oligospirothioketal (OSTK) rods. In this way, some crucial problems arising from the reversible formation of ketals are circumvented. Furthermore, the stability of the rods toward hydrolysis is considerably improved. To successfully implement this concept, we first developed a number of new oligothiol building blocks and improved the synthetic accessibility of known oligothiols, respectively. Another advantage of thioacetals is that terephthalaldehyde (TAA) sleeves, which are too flexible in the case of acetals can be used in OSTK rods. The viability of the OSTK approach was demonstrated by the successful preparation of some OSTK rods with a length of some nanometers.}, language = {en} } @article{PapeWessigBrunner2016, author = {Pape, Simon and Wessig, Pablo and Brunner, Heiko}, title = {Iron Trichloride and Air Mediated Guanylation of Acylthioureas. An Ecological Route to Acylguanidines: Scope and Mechanistic Insights}, series = {The journal of organic chemistry}, volume = {81}, journal = {The journal of organic chemistry}, publisher = {American Chemical Society}, address = {Washington}, issn = {0022-3263}, doi = {10.1021/acs.joc.6b00600}, pages = {4701 -- 4712}, year = {2016}, abstract = {Recently we introduced iron trichloride as an environmentally benign and cost-efficient reagent for the synthesis of N-benzoylguanidines. This highly attractive synthetic approach grants access to a broad spectrum of N-benzoylguanidines under mild conditions in short reaction times. In this work we present an extended scope of Our methodology along with the results obtained from mechanistic studies via in situ IR spectroscopy in combination with LC (liquid chromatography)-MS analyses. On the basis of these new mechanistic insights we were able to optimize the synthetic protocol and to develop an alternative mechanistic proposal. In this context the symbiotic roles of iron trithloride and oxygen in the guanylation process are highlighted.}, language = {en} } @article{WessigBehrendsKumkeetal.2016, author = {Wessig, Pablo and Behrends, Nicole and Kumke, Michael Uwe and Eisold, Ursula}, title = {FRET Pairs with Fixed Relative Orientation of Chromophores}, series = {European journal of organic chemistry}, volume = {145}, journal = {European journal of organic chemistry}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-193X}, doi = {10.1002/ejoc.201600489}, pages = {4476 -- 4486}, year = {2016}, abstract = {Synthetic routes to different oligospirothioketal (OSTK) Forster resonance energy transfer (FRET) constructs are described and the photophysics of these constructs were explored in different solvents. The FRET efficiencies were determined from the experimental data and compared with theoretical values. The influence of the outstanding rigidity of the novel OSTK compounds on the FRET is discussed.}, language = {en} } @article{EisoldBehrendsWessigetal.2016, author = {Eisold, Ursula and Behrends, Nicole and Wessig, Pablo and Kumke, Michael Uwe}, title = {Rigid Rod-Based FRET Probes for Membrane Sensing Applications}, series = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, volume = {120}, journal = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, publisher = {American Chemical Society}, address = {Washington}, issn = {1520-6106}, doi = {10.1021/acs.jpcb.6b07285}, pages = {9935 -- 9943}, year = {2016}, abstract = {Oligospirothioketal (OSTK) rods are presented as an adjustable scaffold for optical membrane probes. The OSTK rods are readily incorporated into lipid bilayers due to their hydrophobic backbones. Because of their high length-over-diameter aspect ratio, only a minimal disturbance of the lipid bilayer is caused. OSTK rods show outstanding rigidity and allow defined labeling with fluorescent dyes, yielding full control of the orientation between the dye and OSTK skeleton. This. allows the construction of novel Forster resonance energy transfer probes with highly defined relative orientations of the transition dipole moments of the donor and acceptor dyes and makes the class of OSTK probes a power-fill, flexible toolbox for optical biosensing applications. Data on steady-state and time-resolved fluorescence experiments investigating the incorporation of coumarin- and [1,3]-dioxolo[4,5-f][1,3]benzo-dioxole-labeled OSTKs in large unilamellar vesicles are presented as a show case.}, language = {en} } @article{StorchMaierWessigetal.2016, author = {Storch, Golo and Maier, Frank and Wessig, Pablo and Trapp, Oliver}, title = {Rotational Barriers of Substituted BIPHEP Ligands: A Comparative Experimental and Theoretical Study}, series = {European journal of organic chemistry}, volume = {22}, journal = {European journal of organic chemistry}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-193X}, doi = {10.1002/ejoc.201600836}, pages = {5123 -- 5126}, year = {2016}, abstract = {The interconversion barriers of 14 different 3,3- and 5,5-disubstituted tropos BIPHEP [2,2-bis(diphenylphosphino)-1,1-biphenyl] and BIPHEP(O) [2,2-bis(diphenylphosphoryl)-1,1-biphenyl] ligands were investigated by enantioselective dynamic high performance liquid chromatography (DHPLC) and DFT calculations using the B3LYP/6-31G* and M06-2X/6-31G* levels of theory. The experimentally determined enantiomerization barriers varied from 86.8 to 101.4 kJmol(-1) and were found to be in excellent agreement with the calculated data. The root-mean-square deviations are 7.3 kJmol(-1) for the B3LYP functional and 11.3 kJmol(-1) for the M06-2X method.}, language = {en} } @misc{WessigHilleKumkeetal.2016, author = {Wessig, Pablo and Hille, Carsten and Kumke, Michael Uwe and Meiling, Till Thomas and Behrends, Nicole and Eisold, Ursula}, title = {Two-photon FRET pairs based on coumarin and DBD dyes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-394445}, pages = {33510 -- 33513}, year = {2016}, abstract = {The synthesis and photophysical properties of two new FRET pairs based on coumarin as a donor and DBD dye as an acceptor are described. The introduction of a bromo atom dramatically increases the two-photon excitation (2PE) cross section providing a 2PE-FRET system, which is also suitable for 2PE-FLIM.}, language = {en} } @misc{WessigBaderKlieretal.2016, author = {Wessig, Pablo and Bader, Denise and Klier, Dennis Tobias and Hettrich, Cornelia and Bier, Frank Fabian}, title = {Detecting carbohydrate-lectin interactions using a fluorescent probe based on DBD dyes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-394382}, pages = {1235 -- 1238}, year = {2016}, abstract = {Herein we present an efficient synthesis of a biomimetic probe with modular construction that can be specifically bound by the mannose binding FimH protein - a surface adhesion protein of E. coli bacteria. The synthesis combines the new and interesting DBD dye with the carbohydrate ligand mannose via a Click reaction. We demonstrate the binding to E. coli bacteria over a large concentration range and also present some special characteristics of those molecules that are of particular interest for the application as a biosensor. In particular, the mix-and-measure ability and the very good photo-stability should be highlighted here.}, language = {en} } @article{PapeWessigBrunner2015, author = {Pape, Simon and Wessig, Pablo and Brunner, Heiko}, title = {A new and environmentally benign synthesis of aroylguanidines using iron trichloride}, series = {RSC Advances}, volume = {5}, journal = {RSC Advances}, number = {123}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2046-2069}, doi = {10.1039/c5ra20869f}, pages = {101408 -- 101411}, year = {2015}, abstract = {A new synthetic approach for the guanylation of aroylthioureas using iron trichloride is presented. Our synthetic method distinguishes itself by benign reaction conditions, low costs and a broad product spectrum. The scope of the reaction and calorimetric studies are described.}, language = {en} } @article{HaralampievMertensSchwarzeretal.2015, author = {Haralampiev, Ivan and Mertens, Monique and Schwarzer, Roland and Herrmann, Andreas and Volkmer, Rudolf and Wessig, Pablo and Mueller, Peter}, title = {Recruitment of SH-Containing peptides to lipid and biological membranes through the use of a palmitic acid functionalized with a Maleimide Group}, series = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, volume = {54}, journal = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1433-7851}, doi = {10.1002/anie.201408089}, pages = {323 -- 326}, year = {2015}, abstract = {This study presents a novel and easily applicable approach to recruit sulfhydryl-containing biomolecules to membranes by using a palmitic acid which is functionalized with a maleimide group. Notably, this strategy can also be employed with preformed (biological) membranes. The applicability of the assay is demonstrated by characterizing the binding of a Rhodamine-labeled peptide to lipid and cellular membranes using methods of fluorescence spectroscopy, lifetime measurement, and microscopy. Our approach offers new possibilities for preparing biologically active liposomes and manipulating living cells.}, language = {en} } @article{WessigMerkelMueller2015, author = {Wessig, Pablo and Merkel, Roswitha and Mueller, Peter}, title = {Articulated rods - a novel class of molecular rods based on oligospiroketals (OSK)}, series = {Beilstein journal of organic chemistry}, volume = {11}, journal = {Beilstein journal of organic chemistry}, publisher = {Beilstein-Institut zur F{\"o}rderung der Chemischen Wissenschaften}, address = {Frankfurt, Main}, issn = {1860-5397}, doi = {10.3762/bjoc.11.11}, pages = {74 -- 84}, year = {2015}, abstract = {We developed a new type of molecular rods consisting of two (or more) rigid units linked by a flexible joint. Consequently we called these constructs articulated rods (ARs). The syntheses of ARs were carried out by a flexible and modular approach providing access to a number of compounds with various functionalizations in terminal positions. First applications were presented with pyrene, cinnamoyl and anthracenyl labelled ARs.}, language = {en} } @inproceedings{HaralampievMertensSchwarzeretal.2015, author = {Haralampiev, Ivan and Mertens, Monique and Schwarzer, Roland and Herrmann, Andreas and Volkmer, Rudolf and Wessig, Pablo and M{\"u}ller, Peter}, title = {A palmitic acid functionalized with a maleimide group is used to recruit SH-containing peptides to lipid and biological membranes}, series = {The FEBS journal}, volume = {282}, booktitle = {The FEBS journal}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1742-464X}, pages = {204 -- 204}, year = {2015}, language = {en} } @article{WessigBudachThuenemann2015, author = {Wessig, Pablo and Budach, Dennis B. and Th{\"u}nemann, Andreas F.}, title = {Dendrimers with Oligospiroketal (OSK) Building Blocks: Synthesis and Properties}, series = {Chemistry - a European journal}, volume = {21}, journal = {Chemistry - a European journal}, number = {29}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0947-6539}, doi = {10.1002/chem.201501386}, pages = {10466 -- 10471}, year = {2015}, abstract = {The development of novel dendrimers containing oligospiroketal (OSK) rods as building blocks is described. The linkage between the core unit (CU), branching units (BU), and OSK rods relies on the CuAAC reaction between terminal alkynes and azides. Two different strategies of dendrimer synthesis were investigated and it was found that the convergent approach is clearly superior to the divergent one. SAXS measurements and MD simulations indicate that the obtained dendrimer features a globular structure with very low density. Obviously, the OSK rods stabilize a rather loose mass-fractal structure.}, language = {en} } @article{HeuvelingFrochauxZiomkowskaetal.2014, author = {Heuveling, Johanna and Frochaux, Violette and Ziomkowska, Joanna and Wawrzinek, Robert and Wessig, Pablo and Herrmann, Andreas and Schneider, Erwin}, title = {Conformational changes of the bacterial type I ATP-binding cassette importer HisQMP(2) at distinct steps of the catalytic cycle}, series = {Biochimica et biophysica acta : Biomembranes}, volume = {1838}, journal = {Biochimica et biophysica acta : Biomembranes}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0005-2736}, doi = {10.1016/j.bbamem.2013.08.024}, pages = {106 -- 116}, year = {2014}, abstract = {Prokaryotic solute binding protein-dependent ATP-binding cassette import systems are divided into type land type II and mechanistic differences in the transport process going along with this classification are under intensive investigation. Little is known about the conformational dynamics during the catalytic cycle especially concerning the transmembrane domains. The type I transporter for positively charged amino acids from Salmonella enterica serovar Typhimurium (1A0-Hi5QMP2) was studied by limited proteolysis in detergent solution in the absence and presence of co-factors including ATP, ADP, LAO/arginine, and Mg2+ ions. Stable peptide fragments could be obtained and differentially susceptible cleavage sites were determined by mass spectrometry as Lys-258 in the nucleotide-binding subunit, HisP, and Arg-217/Arg-218 in the transmembrane subunit, HisQ In contrast, transmembrane subunit HisM was gradually degraded but no stable fragment could be detected. HisP and HisQ were equally resistant under pre- and post-hydrolysis conditions in the presence of arginine-loaded solute-binding protein LAO and ATP/ADP. Some protection was also observed with LAO/arginine alone, thus reflecting binding to the transporter in the apo-state and transmembrane signaling. Comparable digestion patterns were obtained with the transporter reconstituted into proteoliposomes and nanodiscs. Fluorescence lifetime spectroscopy confirmed the change of HisQ(R218) to a more apolar microenvironment upon ATP binding and hydrolysis. Limited proteolysis was subsequently used as a tool to study the consequences of mutations on the transport cycle. Together, our data suggest similar conformational changes during the transport cycle as described for the maltose ABC transporter of Escherichia coli, despite distinct structural differences between both systems.}, language = {en} } @article{WessigGerngrossPapeetal.2014, author = {Wessig, Pablo and Gerngross, Maik and Pape, Simon and Bruhns, Philipp and Weber, Jens}, title = {Novel porous materials based on oligospiroketals (OSK)}, series = {RSC Advances}, volume = {4}, journal = {RSC Advances}, number = {59}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2046-2069}, doi = {10.1039/c4ra04437a}, pages = {31123 -- 31129}, year = {2014}, abstract = {New porous materials based on covalently connected monomers are presented. The key step of the synthesis is an acetalisation reaction. In previous years we used acetalisation reactions extensively to build up various molecular rods. Based on this approach, investigations towards porous polymeric materials were conducted by us. Here we wish to present the results of these studies in the synthesis of 1D polyacetals and porous 3D polyacetals. By scrambling experiments with 1D acetals we could prove that exchange reactions occur between different building blocks (evidenced by MALDI-TOF mass spectrometry). Based on these results we synthesized porous 3D polyacetals under the same mild conditions.}, language = {en} } @article{MeynersWawrzinekKraemeretal.2014, author = {Meyners, Christian and Wawrzinek, Robert and Kraemer, Andreas and Hinz, Steffen and Wessig, Pablo and Meyer-Almes, Franz-Josef}, title = {A fluorescence lifetime-based binding assay for acetylpolyamine amidohydrolases from Pseudomonas aeruginosa using a [1,3]dioxolo[4,5-f][1,3]benzodioxole (DBD) ligand probe}, series = {Analytical \& bioanalytical chemistry}, volume = {406}, journal = {Analytical \& bioanalytical chemistry}, number = {20}, publisher = {Springer}, address = {Heidelberg}, issn = {1618-2642}, doi = {10.1007/s00216-014-7886-5}, pages = {4889 -- 4897}, year = {2014}, abstract = {High-throughput assays for drug screening applications have to fulfill particular specifications. Besides the capability to identify even compounds with low potency, one of the major issues is to minimize the number of false-positive hits in a screening campaign in order to reduce the logistic effort for the subsequent cherry picking and confirmation procedure. In this respect, fluorescence lifetime (FLT) appears as an ideal readout parameter that is supposed to be robust against autofluorescent and light-absorbing compounds, the most common source of systematic false positives. The extraordinary fluorescence features of the recently discovered [1,3]dioxolo[4,5-f][1,3]benzodioxole dyes were exploited to develop an FLT-based binding assay with exceptionally robust readout. The assay setup was comprehensively validated and shown to comply not only with all requirements for a powerful high-throughput screening assay but also to be suitable to determine accurate binding constants for inhibitors against enzymes of the histone deacetylase family. Using the described binding assay, the first inhibitors against three members of this enzyme family from Pseudomonas aeruginosa were identified. The compounds were characterized in terms of potency and selectivity profile. The novel ligand probe should also be applicable to other homologues of the histone deacetylase family that are inhibited by N-hydroxy-N'-phenyloctandiamide.}, language = {en} } @article{WessigMoellnitzKellingetal.2011, author = {Wessig, Pablo and M{\"o}llnitz, Kristian and Kelling, Alexandra and Schilde, Uwe}, title = {Crystal structure of 1r,2c,3c,4t,5t,6t-1,2,3,4,5,6-hexakis-trimethylsilanyloxy-cyclohexane, C24H60O6Si6}, series = {Zeitschrift f{\"u}r Kristallographie : international journal for structural, physical and chemical aspects of crystalline materials ; New crystal structures}, volume = {226}, journal = {Zeitschrift f{\"u}r Kristallographie : international journal for structural, physical and chemical aspects of crystalline materials ; New crystal structures}, number = {2}, publisher = {De Gruyter Oldenbourg}, address = {M{\"u}nchen}, issn = {1433-7266}, doi = {10.1524/ncrs.2011.0105}, pages = {228 -- 230}, year = {2011}, abstract = {C24H60O6Si6, triclinic, P (1) over bar (no. 2), a = 11.307(2) angstrom, b = 12.159(2) angstrom, = 16.576(2) angstrom, alpha = 109.47(1)degrees, beta = 94.64(1)degrees, gamma = 111.65(1)degrees, V = 1942.3 angstrom(3), Z = 2, R-gt(F) = 0.043, wR(ref)(F-2) = 0.118, T = 210 K.}, language = {en} } @article{WessigMatthesPick2011, author = {Wessig, Pablo and Matthes, Annika and Pick, Charlotte}, title = {The photo-dehydro-Diels-Alder (PDDA) reaction}, series = {Organic \& biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry}, volume = {9}, journal = {Organic \& biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry}, number = {22}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1477-0520}, doi = {10.1039/c1ob06066j}, pages = {7599 -- 7605}, year = {2011}, abstract = {The photo-dehydro-Diels-Alder (PDDA) reaction is a valuable extension of the classical Diels-Alder (DA) reaction. The PDDA reaction differs from the DA reaction by the replacement of one of the C-C-double bonds of the diene moiety by a C-C triple bond and by the photochemical triggering of the reaction. This entails that, in contrast to the DA reaction, the PDDA reaction proceeds according to a multistage mechanism with biradicals and cycloallenes as intermediates. The PDDA reaction provides access to a considerable variety of compound classes. For example, 1-phenylnaphthlenes, 1,1'-binaphthyls, N-heterocyclic biaryls, and naphthalenophanes could be obtained by this reaction.}, language = {en} } @article{WessigMatthes2011, author = {Wessig, Pablo and Matthes, Annika}, title = {Preparation of Strained Axially Chiral (1,5)Naphthalenophanes by Photo-dehydro-Diels-Alder Reaction}, series = {Journal of the American Chemical Society}, volume = {133}, journal = {Journal of the American Chemical Society}, number = {8}, publisher = {American Chemical Society}, address = {Washington}, issn = {0002-7863}, doi = {10.1021/ja109118m}, pages = {2642 -- 2650}, year = {2011}, abstract = {The preparation of 10 (1,5)naphthalenophanes (10a-j) by photo-dehydro-Diels-Alder (PDDA) reaction is described. Owing to hindered rotation around the biaryl axis, compounds 10 are axially chiral and the separation of enantiomers by chiral HPLC was demonstrated in three cases (10a,b,e). The absolute configuration of the isolated enantiomers could be unambiguously determined by comparison of calculated and measured circular dichroism (CD) spectra. Furthermore, we analyzed ring strain phenomena of (1,5)naphthalenophanes 10. Depending on the length of the linker units, one can distinguish three classes of naphthalenophanes. Compounds 10a-c are highly strained (E-STR = 7-31 kcal/mol), and the strain is caused by small bond angles in the linker unit and deformation of the naphthalene moiety. Another type of strain is observed if the linker unit becomes relatively long (10g,h) originating from transannular interactions and is comparable with the well-known strain of medium sized rings. The naphthalenophanes 10d-f with a linker length of 10-14 atoms are only marginally strained. To clearly discriminate the different sources of strain, we defined two geometrical parameters (average central dihedral angle delta(C) and naphthalene thickness D-N) and demonstrated that they are well-suited to indicate naphthalene deformation of our naphthalenophanes 10 as well as of ten model naphthalenophanes (I-X) with different linker lengths and linking positions.}, language = {en} } @article{WessigPick2011, author = {Wessig, Pablo and Pick, Charlotte}, title = {Photochemical synthesis and properties of axially chiral naphthylpyridines}, series = {Journal of photochemistry and photobiology : A, Chemistry}, volume = {222}, journal = {Journal of photochemistry and photobiology : A, Chemistry}, number = {1}, publisher = {Elsevier}, address = {Lausanne}, issn = {1010-6030}, doi = {10.1016/j.jphotochem.2011.06.006}, pages = {263 -- 265}, year = {2011}, abstract = {Five alkynyl pyridines were prepared and cyclized to naphthylpyridines as the main products in the course of a Photo-Dehydro-Diels-Alder reaction. Four of the final products are axially chiral and the determination of the rotational barrier by DFT calculations, dynamic NMR and H PLC experiments is demonstrated. (C) 2011 Elsevier B.V. All rights reserved.}, language = {en} } @article{WessigPickSchilde2011, author = {Wessig, Pablo and Pick, Charlotte and Schilde, Uwe}, title = {First example of an atropselective dehydro-Diels-Alder (ADDA) reaction}, series = {Tetrahedron letters}, volume = {52}, journal = {Tetrahedron letters}, number = {32}, publisher = {Elsevier}, address = {Oxford}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2011.06.024}, pages = {4221 -- 4223}, year = {2011}, abstract = {A new concept of a stereoselective synthesis of axially chiral biaryls, formed in the course of the dehydro-Diels-Alder (DDA) reaction, has been disclosed. It is based on asymmetric induction of the newly formed chirality axis by a chirality center, which is present in the two synthesized DDA reactants. Depending on the different length of the linkers joining the alkyne moieties the DDA reaction may be triggered photochemically or thermally, where only the thermal variant was stereoselective.}, language = {en} } @article{WessigWawrzinekMoellnitzetal.2011, author = {Wessig, Pablo and Wawrzinek, Robert and Moellnitz, Kristian and Feldbusch, Elvira and Schilde, Uwe}, title = {A new class of fluorescent dyes based on 1,3-benzodioxole and [1,3]-dioxolo[4.5-f]benzodioxole}, series = {Tetrahedron letters}, volume = {52}, journal = {Tetrahedron letters}, number = {46}, publisher = {Elsevier}, address = {Oxford}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2011.09.058}, pages = {6192 -- 6195}, year = {2011}, abstract = {We report on synthesis and photophysical properties of a new class of fluorescent dyes. They are characterized by large Stokes-shifts, long fluorescence lifetimes in organic solvents and a pronounced dependency of the fluorescence lifetime on the solvent polarity. Also worthy of note is the high bleaching stability. To provide access to biochemical and medical applications a series of derivatives were prepared, which exhibit specific reactivity towards different biologically relevant functional groups (carboxylic acids, amines, maleimides, N-hydroxysuccinimide esters). Furthermore, two alkynes were prepared, which could be used in 'Click' chemistry.}, language = {en} } @article{NikolausCzaplaMoellnitzetal.2011, author = {Nikolaus, J{\"o}rg and Czapla, Sylvia and M{\"o}llnitz, Kristian and H{\"o}fer, Chris T. and Herrmann, Andreas and Wessig, Pablo and M{\"u}ller, Peter}, title = {New molecular rods - Characterization of their interaction with membranes}, series = {Biochimica et biophysica acta : Biomembranes}, volume = {1808}, journal = {Biochimica et biophysica acta : Biomembranes}, number = {12}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0005-2736}, doi = {10.1016/j.bbamem.2011.08.008}, pages = {2781 -- 2788}, year = {2011}, abstract = {Molecular rods are synthetical molecules consisting of a hydrophobic backbone which are functionalized with varying terminal groups. Here, we report on the interaction of a recently described new class of molecular rods with lipid and biological membranes. In order to characterize this interaction, different fluorescently labeled rods were synthesized allowing for the application of fluorescence spectroscopy and microscopy based approaches. Our data show that the rods are incorporated into membranes with a perpendicular orientation to the membrane surface and enrich preferentially in liquid-disordered lipid domains. These characteristics underline that rods can be applied as stable membrane-associated anchors for functionalizing membrane surfaces.}, language = {en} } @article{WessigMoellnitz2012, author = {Wessig, Pablo and M{\"o}llnitz, Kristian}, title = {Building blocks for oligospiroketal (OSK) rods and evaluation of their influence on rod rigidity}, series = {The journal of organic chemistry}, volume = {77}, journal = {The journal of organic chemistry}, number = {8}, publisher = {American Chemical Society}, address = {Washington}, issn = {0022-3263}, doi = {10.1021/jo300266b}, pages = {3907 -- 3920}, year = {2012}, abstract = {We report on the synthesis of three new sleeves and their incorporation in OSK rods. The structures of these sleeves are based on neo-inositol, terephthalaldehyde diacetals, and indacene. To quantify the influence of the sleeves on rod rigidity, we applied the worm-like chain (WLC) model on the new rods and found that this approach is rather disappointing. As the chief cause of this result, we assume that the rigidity of typical molecular rods largely exceeds the rigidity of polymers, which were successfully described by the WLC model. Alternatively, we suggest quantifying the rigidity of molecular rods by fitting an empirical function on the end-to-end distance distribution curve obtained by MD simulations. After checking various function types, the Levy-Martin function proved to be most suitable for this purpose. On the basis of this function, we defined the Levy-Martin parameter and suggest using this parameter for the characterization of the rigidity of molecular rods.}, language = {en} } @article{WawrzinekWessigMoellnitzetal.2012, author = {Wawrzinek, Robert and Wessig, Pablo and M{\"o}llnitz, Kristian and Nikolaus, Joerg and Schwarzer, Roland and M{\"u}ller, Peter and Herrmann, Andreas}, title = {DBD dyes as fluorescent probes for sensing lipophilic environments}, series = {Bioorganic \& medicinal chemistry letters : a Tetrahedron publication for rapid dissemination of preliminary communications on all aspects of bioorganic chemistry, medicinal chemistry and related disciplines}, volume = {22}, journal = {Bioorganic \& medicinal chemistry letters : a Tetrahedron publication for rapid dissemination of preliminary communications on all aspects of bioorganic chemistry, medicinal chemistry and related disciplines}, number = {17}, publisher = {Elsevier}, address = {Oxford}, issn = {0960-894X}, doi = {10.1016/j.bmcl.2012.07.056}, pages = {5367 -- 5371}, year = {2012}, abstract = {Small fluorescent organic molecules based on [1,3]dioxolo[4,5-f][1,3]benzodioxole (DBD) could be used as probes for lipophillic microenvironments in aqueous solutions by indicating the critical micelles concentration of detergents and staining cell organelles. Their fluorescence lifetime decreases drastically by the amount of water in their direct environment. Therefore they are potential probes for fluorescence lifetime imaging microscopy (FLIM).}, language = {en} } @article{WessigMatthes2013, author = {Wessig, Pablo and Matthes, Annika}, title = {Photochemical synthesis and properties of 1,6- and 1,8-Naphthalenophanes}, series = {Molecules}, volume = {18}, journal = {Molecules}, number = {1}, publisher = {MDPI}, address = {Basel}, issn = {1420-3049}, doi = {10.3390/molecules18011314}, pages = {1314 -- 1324}, year = {2013}, abstract = {Various 1,6- and 1,8-naphthalenophanes were synthesized by using the Photo-Dehydro-Diels-Alder (PDDA) reaction of bis-ynones. These compounds are easily accessible from omega-(3-iodophenyl)carboxylic acids in three steps. The obtained naphthalenophanes are axially chiral and the activation barrier for the atropisomerization could be determined in some cases by means of dynamic NMR (DNMR) and/or dynamic HPLC (DHPLC) experiments.}, language = {en} } @article{GrimmMeyerCzaplaetal.2013, author = {Grimm, Christiane and Meyer, Thomas and Czapla, Sylvia and Nikolaus, J{\"o}rg and Scheidt, Holger A. and Vogel, Alexander and Herrmann, Andreas and Wessig, Pablo and Huster, Daniel and M{\"u}ller, Peter}, title = {Structure and dynamics of molecular rods in membranes application of a Spin-Labeled rod}, series = {Chemistry - a European journal}, volume = {19}, journal = {Chemistry - a European journal}, number = {8}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0947-6539}, doi = {10.1002/chem.201202500}, pages = {2703 -- 2710}, year = {2013}, abstract = {Molecular rods consisting of a hydrophobic backbone and terminally varying functional groups have been synthesized for applications for the functionalization of membranes. In the present study, we employ a spin-labeled analogue of a recently described new class of molecular rods to characterize their dynamic interactions with membranes. By using the different approaches of ESR and NMR spectroscopy, we show that the spin moiety of the membrane-embedded spin-labeled rod is localized in the upper chain/glycerol region of membranes of different compositions. The rod is embedded within the membrane in a tilted orientation to adjust for the varying hydrophobic thicknesses of these bilayers. This orientation does not perturb the membrane structure. The water solubility of the rod is increased significantly in the presence of certain cyclodextrins. These cyclodextrins also allow the rods to be extracted from the membrane and incorporated into preformed membranes. The latter will improve the future applications of these rods in cellular systems as stable membrane-associated anchors for the functionalization of membrane surfaces.}, language = {en} } @article{WessigMatthesSchildeetal.2013, author = {Wessig, Pablo and Matthes, Annika and Schilde, Uwe and Kelling, Alexandra}, title = {Asymmetric synthesis of (1,5)Naphthalenophanes by Dehydro-Diels-Alder reaction}, series = {European journal of organic chemistry}, journal = {European journal of organic chemistry}, number = {11}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-193X}, doi = {10.1002/ejoc.201201594}, pages = {2123 -- 2129}, year = {2013}, abstract = {An asymmetric variant of the dehydro-Diels-Alder (DDA) reaction has been developed and applied in the atropselective synthesis of various (1,5)naphthalenophanes. Whereas the suitability of the photochemically induced DDA (PDDA) was limited, the thermally induced DDA provided the desired product, depending on the chiral auxiliary used and the length of the linker, with nearly perfect stereoselectivity. Furthermore, the mechanism of the DDA was investigated by means of DFT calculations, and a stepwise mechanism involving 1,4-biradicals was suggested.}, language = {en} } @article{TechenCzaplaMoellnitzetal.2013, author = {Techen, Anne and Czapla, Sylvia and M{\"o}llnitz, Kristian and Budach, Dennis B. and Wessig, Pablo and Kumke, Michael Uwe}, title = {Synthesis and spectroscopic characterization of fluorophore-labeled oligospiroketal rods}, series = {Helvetica chimica acta}, volume = {96}, journal = {Helvetica chimica acta}, number = {11}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0018-019X}, doi = {10.1002/hlca.201200616}, pages = {2046 -- 2067}, year = {2013}, abstract = {Fluorescence probes consisting of well-established fluorophores in combination with rigid molecular rods based on spirane-type structures were investigated with respect to their fluorescence properties under different solvent conditions. The attachment of the dyes was accomplished by 1,3-dipolar cycloaddition between alkynes and azides (click' reaction) and is a prime example for a novel class of sensor constructs. Especially, the attachment of two (different) fluorophores on opposite sides of the molecular rods paves the way to new sensor systems with less bulky (compared to the conventional DNA- or protein-based concepts), nevertheless rigid spacer constructs, e.g., for FRET-based sensing applications. A detailed photophysical characterization was performed in MeOH (and in basic H2O/MeOH mixtures) for i) rod constructs containing carboxyfluorescein, ii) rod constructs containing carboxyrhodamine, iii) rod constructs containing both carboxyfluorescein and carboxyrhodamine, and iv) rod constructs containing both pyrene and perylene parts. For each dye (pair), two rod lengths with different numbers of spirane units were synthesized and investigated. The rod constructs were characterized in ensemble as well as single-molecule fluorescence experiments with respect to i) specific roddye and ii) dyedye interactions. In addition to MeOH and MeOH/NaOH, the rod constructs were also investigated in micellar systems, which were chosen as a simplified model for membranes.}, language = {en} } @article{WawrzinekZiomkowskaHeuvelingetal.2013, author = {Wawrzinek, Robert and Ziomkowska, Joanna and Heuveling, Johanna and Mertens, Monique and Herrmann, Andreas and Schneider, Erwin and Wessig, Pablo}, title = {DBD Dyes as Fluorescence Lifetime Probes to Study Conformational Changes in Proteins}, series = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {19}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, number = {51}, publisher = {WILEY-V C H VERLAG GMBH}, address = {WEINHEIM}, issn = {0947-6539}, doi = {10.1002/chem.201302368}, pages = {17349 -- 17357}, year = {2013}, abstract = {Previously, [1,3]dioxolo[4,5-f][1,3]benzodioxole (DBD)-based fluorophores used as highly sensitive fluorescence lifetime probes reporting on their microenvironmental polarity have been described. Now, a new generation of DBD dyes has been developed. Although they are still sensitive to polarity, in contrast to the former DBD dyes, they have extraordinary spectroscopic properties even in aqueous surroundings. They are characterized by long fluorescence lifetimes (10-20ns), large Stokes shifts (approximate to 100nm), high photostabilities, and high quantum yields (>0.56). Here, the spectroscopic properties and synthesis of functionalized derivatives for labeling biological targets are described. Furthermore, thio-reactive maleimido derivatives of both DBD generations show strong intramolecular fluorescence quenching. This mechanism has been investigated and is found to undergo a photoelectron transfer (PET) process. After reaction with a thiol group, this fluorescence quenching is prevented, indicating successful bonding. Being sensitive to their environmental polarity, these compounds have been used as powerful fluorescence lifetime probes for the investigation of conformational changes in the maltose ATP-binding cassette transporter through fluorescence lifetime spectroscopy. The differing tendencies of the fluorescence lifetime change for both DBD dye generations promote their combination as a powerful toolkit for studying microenvironments in proteins.}, language = {en} } @article{WessigMatthesSchilde2010, author = {Wessig, Pablo and Matthes, Annika and Schilde, Uwe}, title = {Crystal structure of 3,4-diacetyl-15,21-dioxatetracyclo- [23.4.0.02,7.06,11]nonacosa-1(29),2,4,6,8,10,25,27- octaene- 14,22-dione{\`u}water (1:2), C31H32O6 · 2H2O}, issn = {1433-7266}, year = {2010}, language = {en} } @article{SchaalKotzurDekowskietal.2009, author = {Schaal, Janina and Kotzur, Nico and Dekowski, Brigitte and Quilitz, Jana and Klimakow, Maria and Wessig, Pablo and Hagen, Volker}, title = {A novel photorearrangement of (coumarin-4-yl)methyl phenyl ethers}, issn = {1010-6030}, doi = {10.1016/j.jphotochem.2009.09.012}, year = {2009}, abstract = {In the present study, we describe synthesis and photochemical behaviour of the coumarinylmethyl phenyl ethers 1 and 6-10. Irradiation of the compounds in polar solvents leads to o-, p- and m-hydroxybenzyl substituted coumarins as main products. A side reaction is the photosolvolysis of the ethers that gives the (coumarin-4-yl)methyl alcohol and the corresponding phenol. Detailed studies of the quantum yields and product distributions upon irradiation of 6 as a function of the solvents are indicative of a dominant role of an ionic pathway in photochemical conversions. The found photochemical rearrangement is a useful tool for the preparation of hydroxylated 4-benzylcoumarins. A series of such compounds have been synthesised.}, language = {en} } @article{MuellerNikolausSchilleretal.2009, author = {M{\"u}ller, Peter and Nikolaus, J{\"o}rg and Schiller, Sabine and Herrmann, Andreas and Moellnitz, Kristian and Czapla, Sylvia and Wessig, Pablo}, title = {Molecular rods with oligospiroketal backbones as anchors in biological membranes}, issn = {1433-7851}, doi = {10.1002/anie.200901133}, year = {2009}, abstract = {Getting stuck in: A hydrophobic molecular rod with terminal fluorescent moieties has been synthesized. The insertion of the rod into membranes was investigated and shown to incorporate efficiently into model and biological membranes (see picture; gray C, blue N, red O). Those rods can be used as stable membrane-associated anchors for functionalization of membrane surfaces.}, language = {en} } @article{WessigMoellnitzHuebner2010, author = {Wessig, Pablo and M{\"o}llnitz, Kristian and H{\"u}bner, Sebastian}, title = {A short and efficient route from myo- to neo-inositol}, issn = {0936-5214}, doi = {10.1055/s-0029-1220071}, year = {2010}, abstract = {An efficient route from myo- to neo-inositol is described. The key steps of the sequence are oxidation of the hydroxy group at C-5 to the corresponding ketone, followed by a highly (dr = 7.8:1) stereoselective reduction. The route includes nine steps with an overall yield of 51\% and is therefore superior to all hitherto reported methods for the preparation of neo-inositol.}, language = {en} } @misc{PapeWessigBrunner2015, author = {Pape, Simon and Wessig, Pablo and Brunner, Heiko}, title = {A new and environmentally benign synthesis of aroylguanidines using iron trichloride}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-102720}, pages = {101408 -- 101411}, year = {2015}, abstract = {A new synthetic approach for the guanylation of aroylthioureas using iron trichloride is presented. Our synthetic method distinguishes itself by benign reaction conditions, low costs and a broad product spectrum. The scope of the reaction and calorimetric studies are described.}, language = {en} } @misc{KlaperWessigLinker2015, author = {Klaper, M. and Wessig, Pablo and Linker, Torsten}, title = {Base catalysed decomposition of anthracene endoperoxide}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89676}, pages = {1210 -- 1213}, year = {2015}, abstract = {Catalytic amounts of a weak base are sufficient to induce the decomposition of anthracene endoperoxides to anthraquinone. The mechanism has been elucidated by isolation of intermediates in combination with DFT calculations. The whole process is suitable for the convenient generation of hydrogen peroxide under very mild conditions.}, language = {en} } @article{KlaperWessigLinker2015, author = {Klaper, M. and Wessig, Pablo and Linker, Torsten}, title = {Base catalysed decomposition of anthracene endoperoxide}, series = {Chemical communications : ChemComm}, journal = {Chemical communications : ChemComm}, number = {52}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1364-548X}, doi = {10.1039/C5CC08606J}, pages = {1210 -- 1213}, year = {2015}, abstract = {Catalytic amounts of a weak base are sufficient to induce the decomposition of anthracene endoperoxides to anthraquinone. The mechanism has been elucidated by isolation of intermediates in combination with DFT calculations. The whole process is suitable for the convenient generation of hydrogen peroxide under very mild conditions.}, language = {en} } @misc{WessigGerngrossPapeetal.2014, author = {Wessig, Pablo and Gerngroß, Maik and Pape, Simon and Bruhns, Philipp and Weber, Jens}, title = {Novel porous materials based on oligospiroketals (OSK)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-74466}, pages = {31123 -- 31129}, year = {2014}, abstract = {New porous materials based on covalently connected monomers are presented. The key step of the synthesis is an acetalisation reaction. In previous years we used acetalisation reactions extensively to build up various molecular rods. Based on this approach, investigations towards porous polymeric materials were conducted by us. Here we wish to present the results of these studies in the synthesis of 1D polyacetals and porous 3D polyacetals. By scrambling experiments with 1D acetals we could prove that exchange reactions occur between different building blocks (evidenced by MALDI-TOF mass spectrometry). Based on these results we synthesized porous 3D polyacetals under the same mild conditions.}, language = {en} } @article{WessigGerngrossPapeetal.2014, author = {Wessig, Pablo and Gerngroß, Maik and Pape, Simon and Bruhns, Philipp and Weber, Jens}, title = {Novel porous materials based on oligospiroketals (OSK)}, series = {RSC Advances : an international journal to further the chemical sciences}, volume = {2014}, journal = {RSC Advances : an international journal to further the chemical sciences}, number = {4}, issn = {2046-2069}, doi = {10.1039/c4ra04437a}, pages = {31123 -- 31129}, year = {2014}, abstract = {New porous materials based on covalently connected monomers are presented. The key step of the synthesis is an acetalisation reaction. In previous years we used acetalisation reactions extensively to build up various molecular rods. Based on this approach, investigations towards porous polymeric materials were conducted by us. Here we wish to present the results of these studies in the synthesis of 1D polyacetals and porous 3D polyacetals. By scrambling experiments with 1D acetals we could prove that exchange reactions occur between different building blocks (evidenced by MALDI-TOF mass spectrometry). Based on these results we synthesized porous 3D polyacetals under the same mild conditions.}, language = {en} }