TY  - JOUR
A1  - Lu, Yong-Ping
A1  - Reichetzeder, Christoph
A1  - Prehn, Cornelia
A1  - von Websky, Karoline
A1  - Slowinski, Torsten
A1  - Chen, You-Peng
A1  - Yin, Liang-Hong
A1  - Kleuser, Burkhard
A1  - Yang, Xue-Song
A1  - Adamski, Jerzy
A1  - Hocher, Berthold
T1  - Fetal serum metabolites are independently associated with Gestational diabetes mellitus
JF  - Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology
N2  - Background/Aims: Gestational diabetes (GDM) might be associated with alterations in the metabolomic profile of affected mothers and their offspring. Until now, there is a paucity of studies that investigated both, the maternal and the fetal serum metabolome in the setting of GDM. Mounting evidence suggests that the fetus is not just passively affected by gestational disease but might play an active role in it. Metabolomic studies performed in maternal blood and fetal cord blood could help to better discern distinct fetal from maternal disease interactions. Methods: At the time of birth, serum samples from mothers and newborns (cord blood samples) were collected and screened for 163 metabolites utilizing tandem mass spectrometry. The cohort consisted of 412 mother/child pairs, including 31 cases of maternal GDM. Results: An initial non-adjusted analysis showed that eight metabolites in the maternal blood and 54 metabolites in the cord blood were associated with GDM. After Benjamini-Hochberg (BH) procedure and adjustment for confounding factors for GDM, fetal phosphatidylcholine acyl-alkyl C 32:1 and proline still showed an independent association with GDM. Conclusions: This study found metabolites in cord blood which were associated with GDM, even after adjustment for established risk factors of GDM. To the best of our knowledge, this is the first study demonstrating an independent association between fetal serum metabolites and maternal GDM. Our findings might suggest a potential effect of the fetal metabolome on maternal GDM. (c) 2018 The Author(s) Published by S. Karger AG, Basel
KW  - Gestational diabetes
KW  - Metabolomics
KW  - Phosphatidylcholine acyl-alkyl C 32:1
KW  - Proline
Y1  - 2018
U6  - https://doi.org/10.1159/000487119
SN  - 1015-8987
SN  - 1421-9778
VL  - 45
IS  - 2
SP  - 625
EP  - 638
PB  - Karger
CY  - Basel
ER  - 
TY  - JOUR
A1  - Lu, Yong-Ping
A1  - Reichetzeder, Christoph
A1  - Prehn, Cornelia
A1  - Yin, Liang-Hong
A1  - Yun, Chen
A1  - Zeng, Shufei
A1  - Chu, Chang
A1  - Adamski, Jerzy
A1  - Hocher, Berthold
T1  - Cord blood Lysophosphatidylcholine 16:1 is positively associated with birth weight
JF  - Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology
N2  - Background/Aims: Impaired birth outcomes, like low birth weight, have consistently been associated with increased disease susceptibility to hypertension in later life. Alterations in the maternal or fetal metabolism might impact on fetal growth and influence birth outcomes. Discerning associations between the maternal and fetal metabolome and surrogate parameters of fetal growth could give new insight into the complex relationship between intrauterine conditions, birth outcomes, and later life disease susceptibility. Methods: Using flow injection tandem mass spectrometry, targeted metabolomics was performed in serum samples obtained from 226 mother/child pairs at delivery. Associations between neonatal birth weight and concentrations of 163 maternal and fetal metabolites were analyzed. Results: After FDR adjustment using the Benjamini-Hochberg procedure lysophosphatidylcholines (LPC) 14:0, 16:1, and 18:1 were strongly positively correlated with birth weight. In a stepwise linear regression model corrected for established confounding factors of birth weight, LPC 16: 1 showed the strongest independent association with birth weight (CI: 93.63 - 168.94; P = 6.94x10(-11)). The association with birth weight was stronger than classical confounding factors such as offspring sex (CI: - 258.81- -61.32; P = 0.002) and maternal smoking during pregnancy (CI: -298.74 - -29.51; P = 0.017). Conclusions: After correction for multiple testing and adjustment for potential confounders, LPC 16:1 showed a very strong and independent association with birth weight. The underlying molecular mechanisms linking fetal LPCs with birth weight need to be addressed in future studies. (c) 2018 The Author(s) Published by S. Karger AG, Basel
KW  - Metabolomics
KW  - Lysophosphatidylcholine
KW  - Birth Weight
KW  - DOHaD
KW  - Hypertension
KW  - Type 2 Diabetes
Y1  - 2018
U6  - https://doi.org/10.1159/000487118
SN  - 1015-8987
SN  - 1421-9778
VL  - 45
IS  - 2
SP  - 614
EP  - 624
PB  - Karger
CY  - Basel
ER  - 
TY  - JOUR
A1  - Muiva-Mutisya, Lois M.
A1  - Atilaw, Yoseph
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Akala, Hoseah M.
A1  - Cheruiyot, Agnes C.
A1  - Brown, Matthew L.
A1  - Irungu, Beatrice
A1  - Okalebo, Faith A.
A1  - Derese, Solomon
A1  - Mutai, Charles
A1  - Yenesew, Abiy
T1  - Antiplasmodial prenylated flavanonols from Tephrosia subtriflora
JF  - Natural Product Research
N2  - The CH2Cl2/MeOH (1:1) extract of the aerial parts of Tephrosia subtriflora afforded a new flavanonol, named subtriflavanonol (1), along with the known flavanone spinoflavanone B, and the known flavanonols MS-II (2) and mundulinol. The structures were elucidated by the use of NMR spectroscopy and mass spectrometry. The absolute configuration of the flavanonols was determined based on quantum chemical ECD calculations. In the antiplasmodial assay, compound 2 showed the highest activity against chloroquine-sensitive Plasmodiumfalciparum reference clones (D6 and 3D7), artemisinin-sensitive isolate (F32-TEM) as well as field isolate (KSM 009) with IC50 values 1.4-4.6M without significant cytotoxicity against Vero and HEp2 cell lines (IC50>100M). The new compound (1) showed weak antiplasmodial activity, IC50 12.5-24.2M, but also showed selective anticancer activity against HEp2 cell line (CC50 16.9M). [GRAPHICS] .
KW  - Tephrosia subtriflora
KW  - Leguminosae
KW  - prenylated flavanonol
KW  - subtriflavanonol
KW  - antiplasmodial
KW  - cytotoxicity
Y1  - 2018
U6  - https://doi.org/10.1080/14786419.2017.1353510
SN  - 1478-6419
SN  - 1478-6427
VL  - 32
IS  - 12
SP  - 1407
EP  - 1414
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Krüger-Genge, Anne
A1  - Schulz, Christian
A1  - Kratz, Karl
A1  - Lendlein, Andreas
A1  - Jung, Friedrich
T1  - Comparison of two substrate materials used as negative control in endothelialization studies
BT  - Glass versus polymeric tissue culture plate
JF  - Clinical hemorheology and microcirculation : blood flow and vessels
N2  - The endothelialization of synthetic surfaces applied as cardiovascular implant materials is an important issue to ensure the anti-thrombotic quality of a biomaterial. However, the rapid and constant development of a functionallycon-fluent endothelial cell monolayer is challenging. In order to investigate the compatibility of potential implant materials with endothelial cells several in vitro studies are performed. Here, glass and tissue culture plates (TCP) are often used as reference materials for in vitro pre-testing. However, a direct comparison of both substrates is lacking. Therefore, a comparison of study results is difficult, since results are often related to various reference materials. In this study, the endothelialization of glass and TCP was investigated in terms of adherence, morphology, integrity, viability and function using human umbilical vein endothelial cells (HUVEC). On both substrates an almost functionally confluent HUVEC monolayer was developed after nine days of cell seeding with clearly visible cell rims, decreased stress fiber formation and a pronounced marginal filament band. The viability of HUVEC was comparable for both substrates nine days after cell seeding with only a few dead cells. According to that, the cell membrane integrity as well as the metabolic activity showed no differences between TCP and glass. However, a significant difference was observed for the secretion of IL-6 and IL-8. The concentration of both cytokines, which are associated with migratory activity, was increased in the supernatant of HUVEC seeded on TCP. This result matches well with the slightly increased number of adherent HUVEC on TCP. In conclusion, these findings indicate that both reference materials are almost comparable and can be used equivalently as control materials in in vitro endothelialization studies.
KW  - Negative control
KW  - endothelial cells
KW  - glass
KW  - TCP
KW  - reference
Y1  - 2018
U6  - https://doi.org/10.3233/CH-189904
SN  - 1386-0291
SN  - 1875-8622
VL  - 69
IS  - 3
SP  - 437
EP  - 445
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Krüger-Genge, A.
A1  - Braune, S.
A1  - Walter, M.
A1  - Krengel, M.
A1  - Kratz, K.
A1  - Küpper, J. H.
A1  - Lendlein, Andreas
A1  - Jung, Friedrich
T1  - Influence of different surface treatments of poly(n-butyl acrylate) networks on fibroblasts adhesion, morphology and viability
JF  - Clinical hemorheology and microcirculation : blood flow and vessels
N2  - BACKGROUND: Physical and chemical characteristics of implant materials determine the fate of long-term cardiovascular devices. However, there is still a lack of fundamental understanding of the molecular mechanisms occurring in the material-tissue interphase. In a previous study, soft covalently crosslinked poly(n-butyl acrylate) networks (cPnBA) were introduced as sterilizable, non-toxic and immuno-compatible biomaterials with mechanical properties adjustable to blood vessels. Here we study the influence of different surface treatments in particular oxygen plasma modification and fibrinogen deposition as well as a combinatorial approach on the adhesion and viability of fibroblasts. RESULTS: Compared to non-treated cPnBAs the advancing water-contact angles were found to be reduced after all surface modifications (p<0.05, each), while lowest values were observed after the combined surface treatment (OPT+FIB). The latter differed significantly from the single OPT and FIB. The number of adherent fibroblasts and their adherence behavior differed on both pristine cPnBA networks. The fibroblast density on cPnBA04 was 743 +/- 434 cells. mm(-2), was about 6.5 times higher than on cPnBA73 with 115 +/- 73 cells. mm(-2). On cPnBA04 about 20% of the cells were visible as very small, round and buckled cells while all other cells were in a migrating status. On cPnBA73, nearly 50% of fibroblasts were visible as very small, round and buckled cells. The surface functionalization either using oxygen plasma treatment or fibrinogen coating led to a significant increase of adherent fibroblasts, particularly the combination of both techniques, for both cPnBA networks. It is noteworthy to mention that the fibrinogen coating overruled the characteristics of the pristine surfaces; here, the fibroblast densities after seeding were identical for both cPnBAnetworks. Thus, the binding rather depended on the fibrinogen coating than on the substrate characteristics anymore. While the integrity of the fibroblasts membrane was comparable for both polymers, the MTS tests showed a decreased metabolic activity of the fibroblasts on cPnBA. CONCLUSION: The applied surface treatments of cPnBA successfully improved the adhesion of viable fibroblasts. Under resting conditions as well as after shearing the highest fibroblast densities were found on surfaces with combined post-treatment.
KW  - Biomaterial
KW  - poly(n-butyl acrylate)
KW  - fibroblast
KW  - oxygen plasma
KW  - fibrinogen
KW  - cell adhesion
KW  - focal adhesion
KW  - actin cytoskeleton
KW  - viability
Y1  - 2018
U6  - https://doi.org/10.3233/CH-189130
SN  - 1386-0291
SN  - 1875-8622
VL  - 69
IS  - 1-2
SP  - 305
EP  - 316
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Kumar, Reddi K.
A1  - Heuchel, Matthias
A1  - Kratz, Karl
A1  - Lendlein, Andreas
A1  - Jankowski, Joachim
A1  - Tetali, Sarada D.
T1  - Effects of extracts prepared from modified porous poly(ether imide) microparticulate absorbers on cytotoxicity, macrophage differentiation and proinflammatory behavior of human monocytic (THP-1) cells
JF  - Clinical hemorheology and microcirculation : blood flow and vessels
N2  - Remaining uremic toxins in the blood of chronic renal failure patients represent one central challenge in hemodialysis therapies. Highly porous poly(ether imide) (PEI) microparticles have been recently introduced as candidate absorber materials, which show a high absorption capacity for uremic toxins and allow hydrophilic surface modification suitable for minimization of serum protein absorption. In this work, the effects of extracts prepared from PEI microparticles modified by nucleophilic reaction with low molecular weight polyethylene imine (Pei) or potassium hydroxide (KOH), on human monocytic (THP-1) cells are studied. The obtained results suggested that the extracts of Pei and KOH modified PEI absorbers have no negative effect on THP-1 cell viability and do not initiate the critical differentiation towards macrophages. The extracts did not enhance transcript or protein levels of investigated proinflammatory markers in THP-1 cells, namely, TNF alpha, MCP1, IL6 and IL8. Based on these findings such modified PEI microparticles should be qualified for further pre-clinical evaluation i.e. in an in vivo animal experiment.
KW  - Chronic kidney disease
KW  - hemodialysis
KW  - Inflammation
KW  - Porous poly(ether imide) microparticulate absorbers
KW  - THP-1 cells
KW  - Uremic toxins
Y1  - 2018
U6  - https://doi.org/10.3233/CH-189112
SN  - 1386-0291
SN  - 1875-8622
VL  - 69
IS  - 1-2
SP  - 175
EP  - 185
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Giulbudagian, Michael
A1  - Yealland, Guy
A1  - Hönzke, S.
A1  - Edlich, A.
A1  - Geisendörfer, Birte
A1  - Kleuser, Burkhard
A1  - Hedtrich, Sarah
A1  - Calderon, Marcelo
T1  - Breaking the Barrier
BT  - potent anti-inflammatory activity following efficient topical delivery of etanercept using thermoresponsive nanogels
JF  - Theranostics
N2  - Topical administration permits targeted, sustained delivery of therapeutics to human skin. Delivery to the skin, however, is typically limited to lipophilic molecules with molecular weight of < 500 Da, capable of crossing the stratum corneum. Nevertheless, there are indications protein delivery may be possible in barrier deficient skin, a condition found in several inflammatory skin diseases such as psoriasis, using novel nanocarrier systems. Methods: Water in water thermo-nanoprecipitation; dynamic light scattering; zeta potential measurement; nanoparticle tracking analysis; atomic force microscopy; cryogenic transmission electron microscopy; UV absorption; centrifugal separation membranes; bicinchoninic acid assay; circular dichroism; TNF alpha binding ELISA; inflammatory skin equivalent construction; human skin biopsies; immunohistochemistry; fluorescence microscopy; western blot; monocyte derived Langerhans cells; ELISA Results: Here, we report the novel synthesis of thermoresponsive nanogels (tNG) and the stable encapsulation of the anti-TNFa fusion protein etanercept (ETR) (similar to 150 kDa) without alteration to its structure, as well as temperature triggered release from the tNGs. Novel tNG synthesis without the use of organic solvents was conducted, permitting in situ encapsulation of protein during assembly, something that holds great promise for easy manufacture and storage. Topical application of ETR loaded tNGs to inflammatory skin equivalents or tape striped human skin resulted in efficient ETR delivery throughout the SC and into the viable epidermis that correlated with clear anti-inflammatory effects. Notably, effective ETR delivery depended on temperature triggered release following topical application. Conclusion: Together these results indicate tNGs hold promise as a biocompatible and easy to manufacture vehicle for stable protein encapsulation and topical delivery into barrier-deficient skin.
KW  - thermoresponsive-nanogel
KW  - topical
KW  - anti-inflammatory therapy
KW  - etanercept
KW  - skin equivalents
Y1  - 2018
U6  - https://doi.org/10.7150/thno.21668
SN  - 1838-7640
VL  - 8
IS  - 2
SP  - 450
EP  - 463
PB  - Ivyspring International Publisher
CY  - Lake haven
ER  - 
TY  - JOUR
A1  - Zimmermann, Marc
A1  - Grigoriev, Dmitry
A1  - Puretskiy, Nikolay
A1  - Böker, Alexander
T1  - Characteristics of microcontact printing with polyelectrolyte ink for the precise preparation of patches on silica particles
JF  - RSC Advances
N2  - This publication demonstrates the abilities of a precise and straightforward microcontact printing approach for the preparation of patchy silica particles. In a broad particle size range, it is possible to finely tune the number and parameters of three-dimensional patches like diameter and thickness using only polyethyleneimine ink, poly(dimethoxysilane) as stamp material and a suitable release solvent.
Y1  - 2018
U6  - https://doi.org/10.1039/c8ra07955b
SN  - 2046-2069
VL  - 8
IS  - 69
SP  - 39241
EP  - 39247
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Razzaq, Muhammad Yasar
A1  - Behl, Marc
A1  - Lendlein, Andreas
T1  - Thermally-induced actuation of magnetic nanocomposites based on Oligo(ω-pentadecalactone) and covalently integrated magnetic nanoparticles
JF  - MRS advances: a journal of the Materials Research Society (MRS)
N2  - The incorporation of inorganic particles in a polymer matrix has been established as a method to adjust the mechanical performance of composite materials. We report on the influence of covalent integration of magnetic nanoparticles (MNP) on the actuation behavior and mechanical performance of hybrid nanocomposite (H-NC) based shape-memory polymer actuators (SMPA). The H-NC were synthesized by reacting two types of oligo(ω-pentadecalactone) (OPDL) based precursors with terminal hydroxy groups, a three arm OPDL (3 AOPDL, Mn = 6000 g mol•1−1 ) and an OPDL (Mn =3300 g • mol−1 ) coated magnetite nanoparticle (Ø = 10 ± 2 nm), with a diisocyanate. These H-NC were compared to the homopolymer network regarding the actuation performance, contractual stress (σcontr) as well as thermal and mechanical properties. The melting range of the OPDL crystals (ΔTm,OPDL) was shifted in homo polymer networks from 36 ºC − 76 ºC to 41ºC − 81 °C for H-NC with 9 wt% of MNP content. The actuators were explored by variation of separating temperature (Tsep), which splits the OPDL crystalline domain into actuating and geometry determining segments. Tsep was varied in the melting range of the nanocomposites and the actuation capability and contractual stress (σcontr) of the nanocomposite actuators could be adjusted. The reversible strain (εrev) was decreased from 11 ± 0.3% for homo polymer network to 3.2±0.3% for H-NC9 with 9 wt% of MNP indicating a restraining effect of the MNP on chain mobility. The results show that the performance of H-NCs in terms of thermal and elastic properties can be tailored by MNP content, however for higher reversible actuation, lower MNP contents are preferable.
Y1  - 2018
U6  - https://doi.org/10.1557/adv.2018.613
SN  - 2059-8521
VL  - 3
IS  - 63
SP  - 3783
EP  - 3791
PB  - Cambridge University Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Krüger, Stefanie
A1  - Schwarze, Michael
A1  - Baumann, Otto
A1  - Günter, Christina
A1  - Bruns, Michael
A1  - Kübel, Christian
A1  - Szabo, Dorothee Vinga
A1  - Meinusch, Rafael
A1  - Bermudez, Veronica de Zea
A1  - Taubert, Andreas
T1  - Bombyx mori silk/titania/gold hybrid materials for photocatalytic water splitting
BT  - combining renewable raw materials with clean fuels
JF  - Beilstein journal of nanotechnology
N2  - The synthesis, structure, and photocatalytic water splitting performance of two new titania (TiO2)/gold(Au)/Bombyx mori silk hybrid materials are reported. All materials are monoliths with diameters of up to ca. 4.5 cm. The materials are macroscopically homogeneous and porous with surface areas between 170 and 210 m(2)/g. The diameter of the TiO2 nanoparticles (NPs) - mainly anatase with a minor fraction of brookite - and the Au NPs are on the order of 5 and 7-18 nm, respectively. Addition of poly(ethylene oxide) to the reaction mixture enables pore size tuning, thus providing access to different materials with different photocatalytic activities. Water splitting experiments using a sunlight simulator and a Xe lamp show that the new hybrid materials are effective water splitting catalysts and produce up to 30 mmol of hydrogen per 24 h. Overall the article demonstrates that the combination of a renewable and robust scaffold such as B. mori silk with a photoactive material provides a promising approach to new monolithic photocatalysts that can easily be recycled and show great potential for application in lightweight devices for green fuel production.
KW  - Bombyx mori silk
KW  - gold
KW  - photocatalytic water splitting
KW  - titania
Y1  - 2018
U6  - https://doi.org/10.3762/bjnano.9.21
SN  - 2190-4286
VL  - 9
SP  - 187
EP  - 204
PB  - Beilstein-Institut zur Förderung der Chemischen Wissenschaften
CY  - Frankfurt, Main
ER  - 
TY  - JOUR
A1  - Schmidt, Bernd
A1  - Schultze, Christiane
T1  - A one-pot synthesis of pyranocoumarins through microwave-promoted propargyl claisen rearrangement/wittig olefination
JF  - European journal of organic chemistry
N2  - The reaction between propargyl ethers of hydroxybenzaldehydes and the ylide ethyl (triphenylphosphoranylidene)acetate was carried out under microwave irradiation to regioselectively afford angular pyranocoumarins. The chromene and coumarin heterocyclic scaffolds were simultaneously formed in the same synthetic step without changing the reaction conditions. The natural products seselin, braylin, and dipetalolactone were among the products synthesized by this method.
KW  - Domino reactions
KW  - Alkynes
KW  - Arenes
KW  - Oxygen heterocycles
KW  - Microwave chemistry
KW  - Rearrangement
Y1  - 2017
SN  - 1434-193X
SN  - 1099-0690
VL  - 2018
IS  - 2
SP  - 223
EP  - 227
PB  - Wiley-VCH Verl.
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Xiong, Tao
A1  - Włodarczyk, Radosław Stanisław
A1  - Gallandi, Lukas
A1  - Körzdörfer, Thomas
A1  - Saalfrank, Peter
T1  - Vibrationally resolved photoelectron spectra of lower diamondoids
BT  - a time-dependent approach
JF  - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistry
N2  - Vibrationally resolved lowest-energy bands of the photoelectron spectra (PES) of adamantane, diamantane, and urotropine were simulated by a time-dependent correlation function approach within the harmonic approximation. Geometries and normal modes for neutral and cationic molecules were obtained from B3LYP hybrid density functional theory (DFT). It is shown that the simulated spectra reproduce the experimentally observed vibrational finestructure (or its absence) quite well. Origins of the finestructure are discussed and related to recurrences of autocorrelation functions and dominant vibrations. Remaining quantitative and qualitative errors of the DFT-derived PES spectra refer to (i) an overall redshift by ∼0.5 eV and (ii) the absence of satellites in the high-energy region of the spectra. The former error is shown to be due to the neglect of many-body corrections to ordinary Kohn-Sham methods, while the latter has been argued to be due to electron-nuclear couplings beyond the Born-Oppenheimer approximation [Gali et al., Nat. Commun. 7, 11327 (2016)].
Y1  - 2018
U6  - https://doi.org/10.1063/1.5012131
SN  - 0021-9606
SN  - 1089-7690
VL  - 148
IS  - 4
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Hesse, Julia
A1  - Klier, Dennis Tobias
A1  - Sgarzi, Massimo
A1  - Nsubuga, Anne
A1  - Bauer, Christoph
A1  - Grenzer, Joerg
A1  - Hübner, Rene
A1  - Wislicenus, Marcus
A1  - Joshi, Tanmaya
A1  - Kumke, Michael Uwe
A1  - Stephan, Holger
T1  - Rapid Synthesis of Sub-10nm Hexagonal NaYF4-Based Upconverting Nanoparticles using Therminol((R))66
JF  - ChemistryOpen : including thesis treasury
N2  - We report a simple one-pot method for the rapid preparation of sub-10nm pure hexagonal (-phase) NaYF4-based upconverting nanoparticles (UCNPs). Using Therminol((R))66 as a co-solvent, monodisperse UCNPs could be obtained in unusually short reaction times. By varying the reaction time and reaction temperature, it was possible to control precisely the particle size and crystalline phase of the UCNPs. The upconversion (UC) luminescence properties of the nanocrystals were tuned by varying the concentrations of the dopants (Nd3+ and Yb3+ sensitizer ions and Er3+ activator ions). The size and phase-purity of the as-synthesized core and core-shell nanocrystals were assessed by using complementary transmission electron microscopy, dynamic light scattering, X-ray diffraction, and small-angle X-ray scattering studies. In-depth photophysical evaluation of the UCNPs was pursued by using steady-state and time-resolved luminescence spectroscopy. An enhancement in the UC intensity was observed if the nanocrystals, doped with optimized concentrations of lanthanide sensitizer/activator ions, were further coated with an inert/active shell. This was attributed to the suppression of surface-related luminescence quenching effects.
KW  - core-shell materials
KW  - lanthanides
KW  - nanostructures
KW  - photoluminescence
KW  - upconversion
Y1  - 2018
U6  - https://doi.org/10.1002/open.201700186
SN  - 2191-1363
VL  - 7
IS  - 2
SP  - 159
EP  - 168
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Yaouba, Souaibou
A1  - Koch, Andreas
A1  - Guantai, Eric M.
A1  - Derese, Solomon
A1  - Irungu, Beatrice
A1  - Heydenreich, Matthias
A1  - Yenesew, Abiy
T1  - Alkenyl cyclohexanone derivatives from Lannea rivae and Lannea schweinfurthii
JF  - Phytochemistry letters / Phytochemical Society of Europe
N2  - Phytochemical investigation of the CH2Cl2/MeOH (1:1) extract of the roots of Lannea rivae (Chiov) Sacleux (Anacardiaceae) led to the isolation of a new alkenyl cyclohexenone derivative: (4R,6S)-4,6-dihydroxy-6-((Z)-nonadec-14′-en-1-yl)cyclohex-2-en-1-one (1), and a new alkenyl cyclohexanol derivative: (2S*,4R*,5S*)-2,4,5-trihydroxy-2-((Z)-nonadec-14′-en-1-yl)cyclohexanone (2) along with four known compounds, namely epicatechin gallate, taraxerol, taraxerone and β-sitosterol; while the stem bark afforded two known compounds, daucosterol and lupeol. Similar investigation of the roots of Lannea schweinfurthii (Engl.) Engl. led to the isolation of four known compounds: 3-((E)-nonadec-16′-enyl)phenol, 1-((E)-heptadec-14′-enyl)cyclohex-4-ene-1,3-diol, catechin, and 1-((E)-pentadec-12′-enyl)cyclohex-4-ene-1,3-diol. The structures of the isolated compounds were determined by NMR spectroscopy and mass spectrometry. The absolute configuration of compound 1 was established by quantum chemical ECD calculations. In an antibacterial activity assay using the microbroth kinetic method, compound 1 showed moderate activity against Escherichia coli while compound 2 exhibited moderate activity against Staphylococcus aureus. Compound 1 also showed moderate activity against E. coli using the disc diffusion method. The roots extract of L. rivae was notably cytotoxic against both the DU-145 prostate cancer cell line and the Vero mammalian cell line (CC50 = 5.24 and 5.20 μg/mL, respectively). Compound 1 was also strongly cytotoxic against the DU-145 cell line (CC50 = 0.55 μg/mL) but showed no observable cytotoxicity (CC50 > 100 μg/mL) against the Vero cell line. The roots extract of L. rivae and L. schweinfurthii, epicatechin gallate as well as compound 1 exhibited inhibition of carageenan-induced inflammation.
KW  - Lannea rivae
KW  - Lannea schweinfurthii
KW  - Alkenyl cyclohexenone
KW  - Alkenyl cyclohexanone
KW  - Anti-inflammatory
KW  - Cytotoxicity
KW  - Antimicrobial
Y1  - 2017
U6  - https://doi.org/10.1016/j.phytol.2017.12.001
SN  - 1874-3900
SN  - 1876-7486
VL  - 23
SP  - 141
EP  - 148
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Dai, Xiaolin
A1  - Mate, Diana M.
A1  - Glebe, Ulrich
A1  - Garakani, Tayebeh Mirzaei
A1  - Körner, Andrea
A1  - Schwaneberg, Ulrich
A1  - Böker, Alexander
T1  - Sortase-mediated ligation of purely artificial building blocks
JF  - Polymers
N2  - Sortase A (SrtA) from Staphylococcus aureus has been often used for ligating a protein with other natural or synthetic compounds in recent years. Here we show that SrtA-mediated ligation (SML) is universally applicable for the linkage of two purely artificial building blocks. Silica nanoparticles (NPs), poly(ethylene glycol) and poly(N-isopropyl acrylamide) are chosen as synthetic building blocks. As a proof of concept, NP-polymer, NP-NP, and polymer-polymer structures are formed by SrtA catalysis. Therefore, the building blocks are equipped with the recognition sequence needed for SrtA reaction-the conserved peptide LPETG-and a pentaglycine motif. The successful formation of the reaction products is shown by means of transmission electron microscopy (TEM), matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-ToF MS), and dynamic light scattering (DLS). The sortase catalyzed linkage of artificial building blocks sets the stage for the development of a new approach to link synthetic structures in cases where their synthesis by established chemical methods is complicated.
KW  - sortase-mediated ligation
KW  - enzymes
KW  - block copolymers
KW  - nanoparticles
Y1  - 2018
U6  - https://doi.org/10.3390/polym10020151
SN  - 2073-4360
VL  - 10
IS  - 2
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Sun, Fu
A1  - Osenberg, Markus
A1  - Dong, Kang
A1  - Zhou, Dong
A1  - Hilger, Andre
A1  - Jafta, Charl J.
A1  - Risse, Sebastian
A1  - Lu, Yan
A1  - Markoetter, Henning
A1  - Manke, Ingo
T1  - Correlating Morphological Evolution of Li Electrodes with Degrading Electrochemical Performance of Li/LiCoO2 and Li/S Battery Systems
BT  - Investigated by Synchrotron X-ray Phase Contrast Tomography
JF  - ACS energy letters / American Chemical Society
N2  - Efficient Li utilization is generally considered to be a prerequisite for developing next-generation energy storage systems (ESSs). However, uncontrolled growth of Li microstructures (LmSs) during electrochemical cycling has prevented its practical commercialization. Herein, we attempt to understand the correlation of morphological evolution of Li electrodes with degrading electrochemical performances of Li/LiCoO2 and Li/S systems by synchrotron X-ray phase contrast tomography technique. It was found that the continuous transformation of the initial dense Li bulk to a porous lithium interface (PL1) structure intimately correlates with the gradually degrading overall cell performance of these two systems. Additionally, the formation mechanism of the PLI and its correlation with previously reported inwardly growing LmS and the lithium-reacted region have been intensively discussed. The information that we gain herein is complementary to previous investigations and may provide general insights into understanding of degradation mechanisms of Li metal anodes and also provide highly needed guidelines for effective design of reliable next-generation Li metal-based ESSs.
Y1  - 2018
U6  - https://doi.org/10.1021/acsenergylett.7b01254
SN  - 2380-8195
VL  - 3
IS  - 2
SP  - 356
EP  - 365
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Schmidt, Bernd
A1  - Petersen, Monib H.
A1  - Braun, Diana
T1  - Bidirectional Synthesis of 6-Acetoxy-5-hexadecanolide, the Mosquito Oviposition Pheromone of Culex quinquefasciatus, from a C-2-Symmetric Building Block Using Olefin Metathesis Reactions
JF  - The journal of organic chemistry
N2  - (5R,6S)-6-Acetoxy-5-hexadecanolide (MOP) is the oviposition pheromone of the mosquito Cx. quinquefasciatus, a vector of pathogens causing a variety of tropical diseases. We describe and evaluate herein three syntheses of MOP starting from mannitol-derived (3R,4R)-hexa-1,5-diene-3,4-diol. This C-2-symmetric building block is elaborated through bidirectional olefin metathesis reactions into 6-epi-MOP, which was converted into MOP via Mitsunobu inversion. The shortest of the three routes makes use of two sequential cross-metathesis reactions and an assisted tandem catalytic olefin reduction, induced by an in situ conversion of a Ru-carbene to a Ru-hydride.
Y1  - 2018
U6  - https://doi.org/10.1021/acs.joc.7b02944
SN  - 0022-3263
VL  - 83
IS  - 3
SP  - 1627
EP  - 1633
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Koch, Andreas
T1  - Paramagnetic ring current effects in anti-aromatic structures subject to substitution/annelation quantified by spatial magnetic properties (TSNMRS)
JF  - Tetrahedron
N2  - The spatial magnetic properties, through-space NMR shieldings (TSNMRS), of the typically anti-aromatic cyclopentadienyl cation, cyclobutadiene, pentalene, s-indacene and of substituted/annelated analogues of the latter structures have been calculated using the CIAO perturbation method employing the nucleus independent chemical shift (NICS) concept and visualized as iso-chemical-shielding surfaces (ICSS) of various size and direction. The TSNMRS values were employed to visualize and quantify the dia(para) magnetic ring current effects in the studied compounds. The interplay of dia(para)magnetic ring current effects due to substitution/annelation caused by heavy exo-cyclic n,pi-electron delocalization can be qualified.
KW  - Aromaticity
KW  - Anti-aromaticity
KW  - Through-space NMR shieldings (TSNMRS)
KW  - GIAO
KW  - NICS
KW  - Annelation effect
Y1  - 2018
U6  - https://doi.org/10.1016/j.tet.2017.12.020
SN  - 0040-4020
VL  - 74
IS  - 7
SP  - 700
EP  - 710
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Chen, Ye
A1  - Song, Qilei
A1  - Zhao, Junpeng
A1  - Gong, Xiangjun
A1  - Schlaad, Helmut
A1  - Zhang, Guangzhao
T1  - Betulin-Constituted multiblock amphiphiles for broad-spectrum protein resistance
JF  - ACS applied materials & interfaces
N2  - Multiblock-like amphiphilic polyurethanes constituted by poly(ethylene oxide) and biosourced betulin are designed for antifouling and synthesized by a convenient organocatalytic route comprising tandem chain-growth and step-growth polymerizations. The doping density of betulin (D-B) in the polymer chain structure is readily varied by a mixed-initiator strategy. The spin-coated polymer films exhibit unique nanophase separation and protein resistance behaviors. Higher D-B leads to enhanced surface hydrophobicity and, unexpectedly, improved protein resistance. It is found that the surface holds molecular-level heterogeneity when D-B is substantially high due to restricted phase separation; therefore, broad-spectrum protein resistance is achieved despite considerable surface hydrophobicity. As D-B decreases, the distance between adjacent betulin units increases so that hydrophobic nanodomains are formed, which provide enough landing areas for relatively small-sized proteins to adsorb on the surface.
KW  - amphiphilic surface
KW  - antifouling
KW  - multiblock copolymer
KW  - organocatalytic polymerization
KW  - renewable resource
Y1  - 2018
U6  - https://doi.org/10.1021/acsami.7b16255
SN  - 1944-8244
VL  - 10
IS  - 7
SP  - 6593
EP  - 6600
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Heinze, Mandy
A1  - Hanschen, Franziska S.
A1  - Wiesner-Reinhold, Melanie
A1  - Baldermann, Susanne
A1  - Gräfe, Jan
A1  - Schreiner, Monika
A1  - Neugart, Susanne
T1  - Effects of Developmental Stages and Reduced UVB and Low UV Conditions on Plant Secondary Metabolite Profiles in Pak Choi (Brassica rapa subsp chinensis)
JF  - Journal of agricultural and food chemistry : a publication of the American Chemical Society
N2  - Pak choi (Brassica rapa subsp. chinensis) is rich in secondary metabolites and contains numerous antioxidants, including flavonoids; hydroxycinnamic acids; carotenoids; chlorophylls; and glucosinolates, which can be hydrolyzed to epithionitriles, nitriles, or isothiocyanates. Here, we investigate the effect of reduced exposure to ultraviolet B (UVB) and UV (UVA and UVB) light at four different developmental stages of pak choi. We found that both the plant morphology and secondary metabolite profiles were affected by reduced exposure to UVB and UV, depending on the plant’s developmental stage. In detail, mature 15- and 30-leaf plants had higher concentrations of flavonoids, hydroxycinnamic acids, carotenoids, and chlorophylls, whereas sprouts contained high concentrations of glucosinolates and their hydrolysis products. Dry weights and leaf areas increased as a result of reduced UVB and low UV. For the flavonoids and hydroxycinnamic acids in 30-leaf plants, less complex compounds were favored, for example, sinapic acid acylated kaempferol triglycoside instead of the corresponding tetraglycoside. Moreover, also in 30-leaf plants, zeaxanthin, a carotenoid linked to protection during photosynthesis, was increased under low UV conditions. Interestingly, most glucosinolates were not affected by reduced UVB and low UV conditions. However, this study underlines the importance of 4-(methylsulfinyl)butyl glucosinolate in response to UVA and UVB exposure. Further, reduced UVB and low UV conditions resulted in higher concentrations of glucosinolate-derived nitriles. In conclusion, exposure to low doses of UVB and UV from the early to late developmental stages did not result in overall lower concentrations of plant secondary metabolites.
KW  - flavonoids
KW  - hydroxycinnamic acids
KW  - carotenoids
KW  - glucosinolates
KW  - nitriles
KW  - UVB reduction
Y1  - 2018
U6  - https://doi.org/10.1021/acs.jafc.7b03996
SN  - 0021-8561
SN  - 1520-5118
VL  - 66
IS  - 7
SP  - 1678
EP  - 1692
PB  - American Chemical Society
CY  - Washington
ER  -