Design of benzimidazole- and benzoxazole-2-thione derivatives as inhibitors of bacterial hyaluronan lyase
摘要:
Bacterial hyaluronan lyases (Hyal) degrade hyaluronan, an important component of the extracellular matrix, and are involved in microbial spread. Hyal inhibitors may serve as tools to study the role of the enzyme, its substrates and products in the course of bacterial infections. Moreover, such enzyme inhibitors are potential candidates for antibacterial combination therapy. Based on crystal structures of Streptococcus pneumoniae Hyal in complex with a hexasaccharide substrate and with different inhibitors, 1-acylated benzimidazole-2-thiones and benzoxazole-2-thiones were derived as new leads for the inhibition of Streptococcus agalactiae strain 4755 Hyal. Structure-based optimization led to N-(3-phenylpropionyl)benzoxazole-2-thione, one of the most potent compounds known to date (IC50 values: 24 mu M at pH 7.4, 15 mu M at pH 5). Among the 27 new derivatives, other N-acylated benzimidazoles and benzoxazoles are just as active at pH 7.4, but not at pH 5. The results support a binding mode characterized by interactions with residues in the catalytic site and with a hydrophobic patch. (C) 2011 Elsevier Masson SAS. All rights reserved.
Photochemical reactions of N-acylbenzoxazole-2-thiones
作者:Takehiko Nishio、Ikuo Iida、Kunio Sugiyama
DOI:10.1039/b002548h
日期:——
presence of a variety of alkenes 2 yields 2-substituted benzoxazoles 3–20 and/or the unexpected products, iminothietanes 21–29 by intramoleculartrapping of the acyl group by thiolate anion of the zwitterionicintermediate I and by the phenolate anion of the zwitterionicintermediate II, respectively, derived from the spirocyclic aminothietanes AT which are formed by regioselective [2+2] cycloaddition of
Acylation and Alkoxycarbony-lation of Benzoxazoline-2-thione and Benzothiazoline-2-thione
作者:Takehiko Nishio、Kiyoko Shiwa
DOI:10.3987/com-03-s(p)10
日期:——
Acylation of benzoxazoline-2-thione (1) and benzothiazoline-2-thione (2) with acetic anhydride (3) and acyl chlorides (4) gave N-acyl (5, 6) and/or S-acyl (7, 8) derivatives depending on the nature of acylating agents and bases used. Alkoxycarbonylation of 1 with aralkyl chlorocarbonates (9) gave N-alkoxycarbonyl derivatives (10) mainly, while that of 2 with aralkyl chloroccarbonates (9) gave S-alkoxycarbonyl derivatives (12) exclusively. Photolysis of N-acyl derivatives (5 or 6) in the presence of alcohols afforded 1 or 2, respectively, together with esters (16).