Anti-biofilm and anti-adherence properties of novel cyclic dipeptides against oral pathogens
摘要:
Microorganisms embedded in a biofilm are significantly more resistant to antimicrobial agents and the defences of the human immune system, than their planktonic counterpart. Consequently, compounds that can inhibit biofilm formation are of great interest for novel therapeutics. In this study, a screening approach was used to identify novel cyclic dipeptides that have anti-biofilm activity against oral pathogens. Five new active compounds were identified that prevent biofilm formation by the cariogenic bacterium Streptococcus mutans and the pathogenic fungus Candida albicans. These compounds also inhibit the adherence of microorganisms to a hydroxylapatite surface. Further investigations were conducted on these compounds to establish the structure-activity relationship, and it was deduced that the common cleft pattern is required for these molecules to act effectively against biofilms.
Synthesis and structural study of piperazine-2,5-diones derived from (R)-cysteine
作者:Asensio González、Svetlana L. Vorob́eva、Ana Linares
DOI:10.1016/0957-4166(95)00168-o
日期:1995.6
Coupling Leuch's anhydrides obtained from (R)-thiazolidine-4-carboxylic acids 1 and 3 with one equivalent of the corresponding ethyl ester derivative of 1 or 3, leads to the formation of chiral piperazine-2,5-diones 2, 4, 5, 6, and 7, on thermal treatment of the intermediate dipeptides. The configuration of the products was established by nOe experiments.
We synthesised a library of cis- and trans-cyclic dipeptides and evaluated their efficacy as catalysts in the asymmetric Weitz-Scheffer epoxidation of trans-chalcone. A thorough investigation relying on structure-activity studies and computational studies provided insights into the mechanism of the process. Our results revealed some structural features required for efficient conversion and for introduction of chirality into the product. The cyclic dipeptide acts as a catalyst by templating a supramolecular arrangement at the aqueous-organic interface required for efficient transformations to occur. Among all cyclic dipeptides investigated, cyclo(Leu-Leu) was the most efficient supramolecular catalyst.[GRAPHICS].
Diketopiperazines from optically active thiazolidine-4-carboxylic acids
作者:Z. Gy�rgyde�k、Z. Dinya、R. Bogn�r
DOI:10.1007/bf00473841
日期:1979.9
A straightforward synthesis and partial hydrolysis of cysteine-derived 2,5-diketopiperazines
A mild and straightforward preparation of cysteine-derived 2,5-diketopiperazines (DKPs) is reported, by cyclization of (R)-2,2-dimethyltetrahydrothiazole-4-carboxylic acid hydrochloride or of (R)-tetrahydrothiazole-4-carboxylic acid hydrochloride, mediated by HBTU and DIEA. One DKP has been characterized by X-ray analysis, while the other has been hydrolyzed to cyclo-Cys-Cys. The preparation of this latter compound has been previously reported to be troublesome and low yielding. (C) 2010 Elsevier Ltd. All rights reserved.
DERDDEHAK Z.; DINYA Z.; BOGNAR R., XIMIYA GETEROTSIKL. SOEDIN., 1979, HO 9, 1211-1220