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Summary There has been a rapid growth of interest in techniques for site-directed drug design, fuelled by the increasing availability of structural models of proteins of therapeutic importance, and by studies reported in the literature showing that potent chemical leads can be obtained by these techniques. Structure generation programs offer the prospect of discovering highly original lead structures from novel chemical families. Due to the fact that this technique is more-or-less still in its infancy, there are no case studies available that demonstrate the use of structure generation programs for site-directed drug design. Such programs were first proposed in 1986, and became commercially available in early 1992. They have shown their ability to reproduce, or suggest reasonable alternatives for, ligands in well-defined binding sites. This brief review will discuss the recent advances that have been made in the field of site-directed structure generation. 相似文献
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Silvio De Bernardini Georg Graf Colin A. Leach Peter Bühlmayer Felix Waldmeier Christoph Tamm 《Helvetica chimica acta》1983,66(2):639-651
The modified nucleoside Πd (1) was used in the synthesis of the oligonucleotide d (TpTpΠpCpGpTpCpApApApApTpC). Diester methodology being unsatisfactory, the triester synthesis was investigated with the unnatural nucleoside. An improved method of nucleoside phosphorylation was developed for the synthesis of the fully-protected nucleotide 2e. This molecule could be cleanly and selectively deprotected, and allowed the efficient synthesis of the desired oligonucleotide. 相似文献
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The rotational contour of the 4683 Å emission band of the o-xylyl radical was studied at high resolution. Calculations of the rotational contour of this hybrid band were made in the rigid rotor approximation for various sets of values of the excited state rotational constants and directions of the transition moment μ. Matching of computed and experimental rotational features showed that μ is oriented at +37° or ?37° with respect to the b inertial axis. The nature of the excited states of o-xylyl and the methyl-to-ring interaction are discussed with respect to these two possible assignments 相似文献
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Rhodium/III/ solutions react with tin/II/ chloride to form a short-lived yellow complex which is extracted by polyurethane foam. Iridium/IV/ solutions are decolourised by tin/II/ chloride but the metal is poorly extracted by foam. The rhodium/III/ complex is readily desorbed from foam using hydrochloric acid and acetone. 相似文献
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Andrew R. Leach Keith Prout Daniel P. Dolata 《Journal of computer-aided molecular design》1988,2(2):107-123
Summary The results of a wide-ranging investigation into some of the different methods available for performing the joining of templates to build molecular models show that the choice of algorithm can significantly affect the quality of the results obtained, and different algorithms are most suited to particular categories of join. 相似文献
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The ene reactions of nitroso compounds were studied with B3LYP/6-31G* geometry optimizations and energy calculations, along with single point energy evaluations using CASPT2/6-31G** and UCCSD(T)/6-311+G* methods. Reactions of HNO with propene and of MeNO and p-NO2C6H4NO with propene or substituted alkenes were also studied. The reaction mechanism is stepwise and involves a polarized diradical intermediate. The electronic structure of this intermediate is between that of a closed shell polar species and that of a pure diradical, and it is stabilized by polar solvents. A weak C-N bonding interaction combined with a CH-O hydrogen bond leads to heightened barriers to rotation about formally single bonds compared to conventional diradicals. Consequently, rotation is slower than hydrogen abstraction and cyclization to form an aziridine N-oxide. This aziridine N-oxide does not lead to ene products without subsequent ring opening but provides a mechanism for the RNO moiety to translate from one end of the alkene to the other. B3LYP calculations are also able to reproduce kinetic isotope effects and regioselectivity. 相似文献
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