Biotransformation of 2 alpha,5 alpha,10 beta,14 beta-tetra-acetoxy-4(20), 11-taxadiene by Ginkgo cell suspension cultures

Ginkgo biloba cell suspension cultures were used to biotransform 2 alpha ,5 alpha ,10 beta ,14 beta -tetra-acetoxy-4(20),11-taxadiene. Two novel compo unds were obtained and their structures were identified as 9 alpha -hydroxy l-2 alpha ,5 alpha ,10 beta ,14 beta -tetra-acetoxy-4(20), 11-taxadiene 1 a nd 9 alpha, 10 beta -dihydroxyl-2 alpha ,5 alpha ,14 beta -tri-acetoxy-4(20 ), 11-taxadiene 2, respectively, on the basis of their physical and chemica l data. Compound 1 was subsequently used as a substrate for the bioconversi on by Ginkgo cell cultures, and the product obtained was confirmed to be ti le same as 2, which suggested that 2 is biosynthesized From 1. investigatio n on properties of the related enzymes responsible for the biotransformatio n reaction through the experimental techniques of cell-free culture and sub strate/product concentration analysis revealed that the enzymes were extrac ellular and constitutive. (C) 2001 Elsevier Science Ltd. All rights reserve d.