Atypical regioselective biohydrolysis on steroidal oxiranes by Aspergillus niger whole cells:: Some stereochemical features

被引：14

作者：

Bisogno, Fabricio R. ^{[1
]}

Orden, Alejandro A. ^{[1
]}

Pranzoni, Celeste Aguirre ^{[1
]}

Cifuente, Diego A. ^{[1
]}

Giordano, Oscar S. ^{[1
]}

Sanz, Marcela Kurina ^{[1
]}

机构：

[1] UNSL, Fac Quim Bioquim & Farm, Area Quim Organ, INTEQUI,CONICET, RA-5700 San Luis, Argentina

来源：

STEROIDS | 2007年 / 72卷 / 08期

关键词：

Aspergillus niger; epoxide hydrolases; steroidal epoxides; diastereoconvergent process;

D O I：

10.1016/j.steroids.2007.04.003

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

5,6-Epoxycholestan-3 beta-ol derivatives were hydrolyzed in a diastereoconvergent manner by growing and resting cells of several strains of Aspergillus niger, particularly A. niger ATCC 11394. These strains displayed opposite regioselectivity toward each isomer in an a and P epoxide mixture, thus, the nucleophilic attack took place at the less substituted and the most substituted carbon atom on each diasteromer, respectively These biocatalysts opened trisubstituted oxiranes but were unable to hydrolyze the disubstituted oxiranes in the tested sterol derivatives. These findings suggest that A. niger strains possess another hydrolytic ability different from the commercial A. niger epoxide hydrolase (EH) that did not accept this kind of steroidal oxiranes as substrates. (c) 2007 Elsevier Inc. All rights reserved.

引用

页码：643 / 652

页数：10

共 29 条

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