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211.
The ability to synthesize nonribosomally small bioactive peptides that find application in modern medicine is widely spread among microorganisms. As broad as the spectrum of biological activities is the structural diversity of these peptides, which are mostly cyclic or branched cyclic compounds containing non-proteinogenic amino acids, small heterocyclic rings and other unusual modifications in the peptide backbone. They are synthesized by multimodular enzymes, the so-called nonribosomal peptide synthetases (NRPSs), from simple building blocks. Biochemical and genetic studies have unveiled the key principles of nonribosomal peptide syntheses, as well as the realization of many structural features of these peptides. This review focuses on recent results in NRPS research and highlights how this knowledge can be exploited for biotechnological purposes. In addition, possibilities and limitations for prediction of structural features of uncharacterized NRPSs and approaches for their engineering are discussed. 相似文献
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Hervé G Hahn DU Hervé AC Goodworth KJ Hill AM Hailes HC 《Organic & biomolecular chemistry》2003,1(2):427-435
Methodologies to access water soluble large ringed calixarenes in good yield using efficient synthetic procedures have been investigated. Symmetrical partial functionalisations at the lower rim are described using activated [n]ethylene glycol chains and the addition behaviour contrasted with that of bromoalkanenitriles which proceeds with no observed regioselectivity. Full functionalisations of the calixarenes bearing hydrophilic groups are then investigated and a two-step procedure established which appears to be generally applicable for the addition of different [n]ethylene glycol chains. Furthermore, difunctionalisation under different reaction conditions are described. Throughout, strategies for the characterisation of these high mass compounds are outlined. 相似文献
218.
Expeditious and high-yielding Nazarov cyclizations of 2-alkoxy-1,4-pentadien-3-ones are described. An example of a catalytic asymmetric Nazarov cyclization is presented. [reaction: see text] 相似文献
219.
Chemler SR Trauner D Danishefsky SJ 《Angewandte Chemie (International ed. in English)》2001,40(24):4544-4568
The development of new reactions that facilitate the creative and efficient synthesis of molecular structures with desirable properties continues to fascinate chemists. The test of a significant contribution is its acceptance over time by the scientific community. The B-alkyl Suzuki-Miyaura cross-coupling reaction appears to be one such reaction. Since its disclosure by Suzuki and Miyaura in 1986, this reaction has been an attractive solution to challenging synthetic problems. 相似文献
220.
Guldi DM Luo C Prato M Troisi A Zerbetto F Scheloske M Dietel E Bauer W Hirsch A 《Journal of the American Chemical Society》2001,123(37):9166-9167