Biotransformation of Bicyclic Sesqui- and Diterpene 1,2-dials and Their Derivatives by the Fungus,Aspergillus niger

Abstract

Microbial biotransformation of naturally occurring pungent sesquiterpene 1,2-dials, polygodial and cinnamodial, and a diterpene 1,2-dial, sacculatal as well as their tetrahydro derivatives was carried out by using Aspergillus niger. The pungent polygodial and sacculatal are toxic against A. niger not to produce any metabolites while A. niger biotransformed cinnamodial to the lactonized products in small amount. On the other hands, the dihydroxy derivatives of the former two dialdehydes were bioconverted by the same fungus to give hydroxy-, oxo-, carboxylic- and epoxy-products. The stereostructures of each metabolite and their metabolic pathways were described.