Microbial transformation of the labdane diterpene 13-epi-cupressic acid

Amal F. Soliman; Zein M. Naeem; Ashraf T. Khalil; Kuniyoshi Shimizu; Saleh H. El-Sharkawy

Authors

Amal F. Soliman Department of Pharmacognosy, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
Zein M. Naeem Department of Pharmacognosy, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
Ashraf T. Khalil Department of Pharmacognosy, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
Kuniyoshi Shimizu Division of Systematic Forest and Forest Products Sciences, Department of Agro-Environmental Sciences, Faculty of Agriculture, Graduate School of Kyushu University, Fukuoka, 812-8581, Japan
Saleh H. El-Sharkawy Department of Pharmacognosy, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt

Keywords:

Araucaria heterophylla, 13-epi-cupressic acid, biotransformation, COX inhibitors

Abstract

The labdane diterpene, 13-epi-cupressic acid 1, was isolated from the n-hexane-chloroform extract of Araucaria heterophylla resin. Of the 20 fungi screened for possible transformation, only four showed to produce metabolites including 13, 14, 15-trihydroxy-8(17)-labden-19-oic acid 2, 7α,13-dihydroxy-8(17),14-labdadien-19-oic acid 3,13-epi-cupressic acid β-glucosyl ester 4 and iso-communic acid 5 by Cunninghamilla echiulata NRRL 1382, Aspergillus restrictus NRRL 2869, Coriolus hirsutus ATCC MYA-828 and Cordyceps sinclairii ATCC 24400, respectively. The identity of the isolated compounds was confirmed using 1D and 2D NMR and MS spectroscopies. Compound 4 is a new metabolite while 5 is first time being produced by biotransformation technique. Compound 3 was proved to be a potent anti-inflammatory agent through selective inhibition of COX-2 enzyme assay.