Microbial Biotransformation of Male Specific Pheromone α-Copaene with Cunninghamella elegans and Antibacterial Activity of Its Transformed Products

Abstract

Pharmaceutical industries are increasingly turning to microbial transformation instead of chemical methods. This is because microbial biotransformation is a more effective way to produce pharmacologically active molecules with high specificity and efficient yield. Additionally, it is a step towards eco-friendly synthesis. α-Copaene (1), a tricyclic sesquiterpene, is a potent attractant of the male Mediterranean fruit fly Ceratitis capitata. This paper presents the utilization of the filamentous fungus Cunninghamella elegans TSY 0865 for large-scale biotransformation of 1. α-Copaene (1) has been incubated with Cunninghamella elegans for 11 days and extracted with CH2Cl2. Four new hydroxylated metabolites 10,13-dihydroxycopaene (2); 11,13-dihydroxycopaene (3); 11-hydroxycopaen-5-one (4); and 11-hydroxy-13-copaenic acid (5) were afforded. The structures of the new metabolites were elucidated by 1D (1H, 13C) and 2D NMR (COSY, HMBC, HMQC, and NOESY) techniques and MS analyses. Metabolite 5 exhibited significant antibacterial activity against Bacillus subtilis and Pseudomonas aeruginosa.