Microbial transformations in a cyclodextrin medium. Part 2. Reduction of androstenedione to testosterone by Saccharomyces cerevisiae |
| |
Authors: | Yossi Singer Halla Shity Raphael Bar |
| |
Affiliation: | (1) Department of Applied Microbiology, The Hebrew University, P. O. Box 1172, 91010 Jerusalem, Israel |
| |
Abstract: | Summary An intensive and systematic investigation of the reductive transformation of androstenedione (AD) to testosterone by Saccharomyces cerevisiae was undertaken in the presence of natural and chemically modified cyclodextrins (CD). The bioconversion was significantly larger in the presence of - and -CD and hydroxypropyl--CD b but only slight in the presence of -CD and dimethyl- and trimethyl--CD. The performance of the various cyclodextrin media was interpreted in the light of the measured phase solubility diagrams of AD. Further investigation focused on biotransformation of the -CD-androstenedione complex, the formation of which was studied by differential scanning calorimetry and X-ray powder diffractometry and stoichiometry determined by 1H-nuclear magnetic resonance. A mechanism whereby CDs reduce the effective inhibitory concentrations of substrate and product as well as facilitate transport of the complexed substrate through the yeast cell wall has been suggested for the CD-promoted biotransformation.Offprint requests to: R. Bar |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |