Microbial transformation of Ursolic acid by Streptomyces griseus subsp. griseus CGMCC 4.18 / 中国药学杂志

ABSTRACT

OBJECTIVE: To modify the structure of Ursolic acid(UA), a pentacyclic triterpene acid, existing a variety of natural plants with extensive biological activities thus to increase the diversity of structure of UA and lay the foundation for screening more active compounds. METHODS: The structure of UA was modified by Streptomyces griseus subsp. griseus CGMCC 4.18 by microbial transformation. RESULTS: A rare hydroxylated at 2 position, product corosolic acid, 2α, 3β-dihydroxy-urs-12-en-28-oic acid which is difficult to obtain by chemical methods and the product 3, 4-seco-ursan-4-hydroxy-12-en-3, 28-dioic acid with cleavage of ring-A were yielded. Interesting, the hydroxylation at C-2 is α configuration that is rare. The structures of product were established based on spectroscopic data and reference compounds. CONCLUSION: The structure diversity of ursolic acid was increased by microbial transformation by Streptomyces. Furteremore, microbial transformation illustrated regional selectivity and high stereo-selectivity.