BIOTRANSFORMATION OF DEHYDROABIETIC ACID WITH MICROBIAL CELL CULTURES AND α-GLUCOSIDASE INHIBITORY ACTIVITY OF RESULTING METABOLITES Original Article

Dehydroabietic acid (DHA, 1), a natural occurring diterpene resin acid, is an abundant resin acid in conifers, representing a natural wood protectant. The aim of this study was to use microbial cell cultures as tools for modification of 1 in order to obtain value-added functional derivatives. A scaledup biotransformation of 1 by filamentous fungus Cunninghamella elegans, Rhizopus stolonifer, Gibberella fujikuroi, and Cephalosporium aphidicola were conducted for the first time. Three hydroxylated metabolites; 1β-hydroxydehydroabietic acid (2); 15-hydroxy dehydroabietic acid (3); and 16hydroxy dehydroabietic acid (4). The structure of the hydroxylated metabolites were elucidated by 1-D (1H, 13C) and 2-D NMR (COSY, HMBC, HMQC, NOESY) techniques and MS analyses. Dehydroabietic acid (1) and their transformed products 2-4 exhibited a promising α-Glucosidase inhibitory activity. Compound 1 showed 38 times more active than the standard α-Glucosidase inhibitor