TY - JOUR A1 - Idzik, Krzysztof Ryszard A1 - Cywinski, Piotr J. A1 - Cranfield, Charles G. A1 - Mohr, Gerhard J. A1 - Beckert, Rainer T1 - Molecular recognition of the antiretroviral drug abacavir towards the development of a novel carbazole-based fluorosensor JF - Journal of fluorescence N2 - Due to their optical and electro-conductive attributes, carbazole derivatives are interesting materials for a large range of biosensor applications. In this study, we present the synthesis routes and fluorescence evaluation of newly designed carbazole fluorosensors that, by modification with uracil, have a special affinity for antiretroviral drugs via either Watson-Crick or Hoogsteen base pairing. To an N-octylcarbazole-uracil compound, four different groups were attached, namely thiophene, furane, ethylenedioxythiophene, and another uracil; yielding four different derivatives. Photophysical properties of these newly obtained derivatives are described, as are their interactions with the reverse transcriptase inhibitors such as abacavir, zidovudine, lamivudine and didanosine. The influence of each analyte on biosensor fluorescence was assessed on the basis of the Stern-Volmer equation and represented by Stern-Volmer constants. Consequently we have demonstrated that these structures based on carbazole, with a uracil group, may be successfully incorporated into alternative carbazole derivatives to form biosensors for the molecular recognition of antiretroviral drugs. KW - HIV KW - HAART KW - Antiretroviral drugs KW - Carbazole KW - Base pairing KW - Fluorescence spectroscopy Y1 - 2011 U6 - https://doi.org/10.1007/s10895-010-0798-7 SN - 1053-0509 SN - 1573-4994 VL - 21 IS - 3 SP - 1195 EP - 1204 PB - Springer CY - New York ER - TY - JOUR A1 - Vidadala, Srinivasa Rao A1 - Pimpalpalle, Tukaram M. A1 - Linker, Torsten A1 - Hotha, Srinivas T1 - Gold-Catalyzed reactions of 2-C-Branched carbohydrates mild glycosidations and selective anomerizations JF - European journal of organic chemistry N2 - 2-C-branched methyl glycosides react with various alcohols under gold catalysis to transglycosylated products. The method is applicable for the convenient synthesis of disaccharides. Without nucleophile a selective anomerization occurs, giving first access to alpha-configured 2-C-nitromethyl glycosides. The results are interesting for the mechanism of gold-catalyzed glycosidations. KW - Anomerization KW - Carbohydrates KW - Glycosidation KW - Gold KW - Synthetic methods Y1 - 2011 U6 - https://doi.org/10.1002/ejoc.201100134 SN - 1434-193X IS - 13 SP - 2426 EP - 2430 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Prieto, Susana A1 - Shkilnyy, Andriy A1 - Rumplasch, Claudia A1 - Ribeiro, Artur A1 - Javier Arias, F. A1 - Carlos Rodriguez-Cabello, Jose A1 - Taubert, Andreas T1 - Biomimetic calcium phosphate mineralization with multifunctional elastin-like recombinamers JF - Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences N2 - Biomimetic hybrid materials based on a polymeric and an inorganic component such as calcium phosphate are potentially useful for bone repair. The current study reports on a new approach toward biomimetic hybrid materials using a set of recombinamers (recombinant protein materials obtained from a synthetic gene) as crystallization additive for calcium phosphate. The recombinamers contain elements from elastin, an elastic structural protein, and statherin, a salivary protein. Via genetic engineering, the basic elastin sequence was modified with the SN(A)15 domain of statherin, whose interaction with calcium phosphate is well-established. These new materials retain the biocompatibility, "smart" nature, and desired mechanical behavior of the elastin-like recombinamer (ELR) family. Mineralization in simulated body fluid (SBF) in the presence of these recombinamers reveals surprising differences. Two of the polymers inhibit calcium phosphate deposition (although they contain the statherin segment). In contrast, the third polymer, which has a triblock structure, efficiently controls the calcium phosphate formation, yielding spherical hydroxyapatite (HAP) nanoparticles with diameters from 1 to 3 nm after 1 week in SBF at 37 degrees C. However, at lower temperatures, no precipitation is observed with any of the polymers. The data thus suggest that the molecular design of ELRs containing statherin segments and the selection of an appropriate polymer structure are key parameters to obtain functional materials for the development of intelligent systems for hard tissue engineering and subsequent in vivo applications. Y1 - 2011 U6 - https://doi.org/10.1021/bm200287c SN - 1525-7797 VL - 12 IS - 5 SP - 1480 EP - 1486 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Kafka, Stanislav A1 - Hauke, Sylvia A1 - Salcinovic, Arjana A1 - Soidinsalo, Otto A1 - Urankar, Damijana A1 - Kosmrlj, Janez T1 - Copper(I)-Catalyzed [3+2] Cycloaddition of 3-Azidoquinoline-2,4(1H,3H)-diones with terminal alkynes JF - Molecules N2 - 3-Azidoquinoline-2,4(1H,3H)-diones 1, which are readily available from 4-hydroxyquinolin-2(1H)-ones 4 via 3-chloroquinoline-2,4(1H, 3H)-diones 5, afford, in copper(I)-catalyzed [3 + 2] cycloaddition reaction with terminal acetylenes, 1,4-disubstituted 1,2,3-triazoles 3 in moderate to excellent yields. The structures of compounds 3 were confirmed by (1)H and (13)C-NMR spectroscopy, combustion analyses and mass spectrometry. KW - cycloaddition KW - azides KW - quinoline-2,4(1H,3H)-diones KW - terminal alkynes KW - 1,2,3-triazoles Y1 - 2011 U6 - https://doi.org/10.3390/molecules16054070 SN - 1420-3049 VL - 16 IS - 5 SP - 4070 EP - 4081 PB - MDPI CY - Basel ER - TY - JOUR A1 - Dudek, Melanie A1 - Clegg, Jack K. A1 - Glasson, Christopher R. K. A1 - Kelly, Norman A1 - Gloe, Kerstin A1 - Gloe, Karsten A1 - Kelling, Alexandra A1 - Buschmann, Hans-Jürgen A1 - Jolliffe, Katrina A. A1 - Lindoy, Leonard F. A1 - Meehan, George V. T1 - Interaction of Copper(II) with Ditopic Pyridyl-beta-diketone Ligands dimeric, framework, and metallogel structures JF - Crystal growth & design : integrating the fields of crystal engineering and crystal growth for the synthesis and applications of new materials N2 - The interaction of Cu(II) with three beta-diketone ligands of type R(1)C(O)CH(2)C(O)R(2) (where R(1) = 2-, 3-, or 4-pyridyl and R(2) = C(6)H(5), respectively), HL(1)-HL(3), along with the X-ray structures and the pK(a) values of each ligand, are reported. HL(1) yields a dimeric complex of type [Cu(L(1))(2)](2). In this structure, two deprotonated HL(1) ligands coordinate in a trans planar fashion around each Cu(II) center, one oxygen from each CuL(2) unit bridges to an axial site of the second complex unit such that both Cu(II) centers attain equivalent five-coordinate square pyramidal geometries. The two-substituted pyridyl groups in this complex do not coordinate, perhaps reflecting steric factors associated with the closeness of the pyridyl nitrogen to the attached (conjugated) beta-diketonato backbone of each ligand. The remaining two Cu(II) species, derived from HL(2) and HL(3), are both coordination polymers of type [Cu(L)(2)](n) in which the terminal pyridine group of each ligand is intermolecularly linked to an adjacent copper center to generate the respective infinite structures. HL(2) was also demonstrated to form a fibrous metallogel when reacted with CuCl(2) in an acetonitrile/water mixture under defined conditions. Y1 - 2011 U6 - https://doi.org/10.1021/cg101629w SN - 1528-7483 VL - 11 IS - 5 SP - 1697 EP - 1704 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Fechner, Mabya A1 - Koetz, Joachim T1 - Polyampholyte-Surfactant film tuning in reverse microemulsions JF - Langmuir N2 - The pH-dependent influence of two different strongly alternating copolymers [poly(N,N'-diallyl-N,N'-dimethylammonium-alt-N-phenylmaleamic carboxylate) (PalPh) and poly(N,N'-diallyl-N,a-dimethylammonium-alt-3,5-bis(carboxyphenyl) maleamic carboxylate) (PalPhBisCarb)] based on N,N'-diallyl-N, -dimethylarnmonium chloride and maleamic acid derivatives on the phase behavior of a water-in-oil (w/o) microemulsion system made from toluene pentanol (1:1) and sodium dodecyl sulfate was investigated. It was shown that the optically dear phase range can be extended after incorporation of these copolymers, leading to an increased water solubilization capacity. Additionally, the required amount of surfactant to establish a clear w/o microemulsion depends on the pH value, which means the hydrophobicity of the copolymers. Conductivity measurements show that droplet droplet interactions in the w/o microemulsion are decreased at acidic but increased at alkaline pH in the presence of the copolymers. From differenctial scanning calorimetry measurements one can further conclude that these results are in agreement with a change of the position of the copolymer in the interfacial region of the surfactant film. The more hydrophobic PalPh can be directly incorporated into the surfactant film, whereas the phenyl groups of PalPhBisCarb flip into the water core by increasing the pH value. Y1 - 2011 U6 - https://doi.org/10.1021/la200791k SN - 0743-7463 VL - 27 IS - 9 SP - 5316 EP - 5323 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Tremblay, Jean Christophe T1 - Laser control of molecular excitations in stochastic dissipative media JF - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr N2 - In the present work, ideas for controlling photochemical reactions in dissipative environments using shaped laser pulses are presented. New time-local control algorithms for the stochastic Schrodinger equation are introduced and compared to their reduced density matrix analog. The numerical schemes rely on time-dependent targets for guiding the reaction along a preferred path. The methods are tested on the vibrational control of adsorbates at metallic surfaces and on the ultrafast electron dynamics in a strong dissipative medium. The selective excitation of the specific states is achieved with improved yield when using the new algorithms. Both methods exhibit similar convergence behavior and results compare well with those obtained using local optimal control for the reduced density matrix. The favorable scaling of the methods allows to tackle larger systems and to control photochemical reactions in dissipative media of molecules with many more degrees of freedom. Y1 - 2011 U6 - https://doi.org/10.1063/1.3587093 SN - 0021-9606 VL - 134 IS - 17 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Adamovich, Sergey N. A1 - Mirskova, Anna N. A1 - Mirskov, Rudolf G. A1 - Schilde, Uwe T1 - Synthesis and crystal structure of 1,4,10,13-tetraoxa-7,16-diazoniumcyclo-octadecane bis(4-chloro-2-methyl-phenoxyacetate) JF - Chemistry central journal N2 - The title compound was prepared by the reaction of 1,4,10,13-tetraoxa-7,16-diazacyclo-octadecane with 4-chloro-2-methyl-phenoxyacetic acid in a ratio of 1:2. The structure has been proved by the data of elemental analysis, IR spectroscopy, NMR ((1)H, (13)C) technique and by X-ray diffraction analysis. Intermolecular hydrogen bonds between the azonium protons and oxygen atoms of the carboxylate groups were found. Immunoactive properties of the title compound have been screened. The compound has the ability to suppress spontaneous and Con A-stimulated cell proliferation in vitro and therefore can be considered as immunodepressant. Y1 - 2011 U6 - https://doi.org/10.1186/1752-153X-5-23 SN - 1752-153X VL - 5 IS - 17 PB - BioMed Central CY - London ER - TY - JOUR A1 - Baranac-Stojanovic, Marija A1 - Keinpeter, Erich T1 - Quantification of the aromaticity of 2-Alkylidenethiazolines subjected to push-pull activity JF - The journal of organic chemistry N2 - Through-space NMR shieldings (TSNMRSs) of a series of 2-alkylidenethiazolines subjected to push-pull activity have been calculated by the GIAO method employing the nucleus-independent chemical shift (NICS) concept and visualized as iso-chemical-shielding surfaces (ICSSs). The ICSSs were applied to quantify and visualize the degree of aromaticity of the studied compounds, which has been shown to be in excellent correlation with the push-pull behavior, quantified by the quotient (pi*/pi) method. Dissection of the absolute magnetic shielding values into individual contributions of bonds and lone pairs by the natural chemical shielding-natural bond orbital (NCS-NBO) analysis has revealed unexpected details. Y1 - 2011 U6 - https://doi.org/10.1021/jo200294f SN - 0022-3263 VL - 76 IS - 10 SP - 3861 EP - 3871 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Poghosyan, Armen H. A1 - Arsenyan, Levon H. A1 - Gharabekyan, Hrant H. A1 - Falkenhagen, Sandra A1 - Koetz, Joachim A1 - Shahinyan, Aram A. T1 - Molecular dynamics simulations of inverse sodium dodecyl sulfate (SDS) micelles in a mixed toluene/pentanol solvent in the absence and presence of poly(diallyldimethylammonium chloride) (PDADMAC) JF - Journal of colloid and interface science N2 - We have performed a 15 ns molecular dynamics simulation of inverse sodium dodecyl sulfate (SDS) micelles in a mixed toluene/pentanol solvent in the absence and presence of a cationic polyelectrolyte, i.e. poly(diallyldimethylammonium chloride) (PDADMAC). The NAMD code and CHARMM force field were used. During the simulation time, the radii of SOS inverse micelles changed and the radii of the water droplets have been calculated. The behavior of SDS hydrocarbon chains has been characterized by calculating the orientation order parameter and the chain average length. The water droplet properties (water flow, water molecules displacement) have been examined. In summary the MD simulations indicate a more rigid and ordered surfactant film due to the formation of a polyelectrolyte palisade layer in full agreement with the experimental findings, e.g. the viscosity increase and shift of the percolation boundary. KW - Surfactant micelles KW - Molecular dynamics simulations KW - SDS Y1 - 2011 U6 - https://doi.org/10.1016/j.jcis.2011.01.091 SN - 0021-9797 VL - 358 IS - 1 SP - 175 EP - 181 PB - Elsevier CY - San Diego ER -