title: Unusual microbial lactonization and hydroxylation of asiatic acid by Umbelopsis isabellina.
abstract: Asiatic acid (1) is a natural triterpenoid isolated from Centella asiatica. This paper reports the microbial transformation of asiatic acid by an endophytic fungus Umbelopsis isabellina to obtain derivatives potentially useful for further studies. Incubation of asiatic acid with U. isabellina afforded two derivatives 2α,3β,7β, 23-tetrahydroxyurs-12-ene-28-oic acid (2) and 2α,3β,7β,23-tetrahydroxyurs-11-ene-28,13-lactone (3). The structures of these compounds were elucidated by spectral data. Compound 3 has formed an unusual lactone. These two products are new compounds. The possible transformation passway was also discussed.
authors.affiliation: a Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College , Beijing 100193 , China.
authors.forename: Zhao-Hui
authors.initials: ZH
authors.lastname: Gao
authors.affiliation: a Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College , Beijing 100193 , China.
authors.forename: Xin-Ran
authors.initials: XR
authors.lastname: Dong
authors.affiliation: a Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College , Beijing 100193 , China.
authors.forename: Ran-Ran
authors.initials: RR
authors.lastname: Gao
authors.affiliation: a Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College , Beijing 100193 , China.
authors.forename: Di-An
authors.initials: DA
authors.lastname: Sun
mesh_terms: D001711:Biotransformation; D028041:Centella / Q000737:chemistry*; D006900:Hydroxylation; D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D009090:Mucorales / Q000737:chemistry; D053978:Pentacyclic Triterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: C000605303:2alpha,3beta,7beta,23-tetrahydroxyurs-12-ene-28-oic acid; D007783:Lactones; D053978:Pentacyclic Triterpenes; D014315:Triterpenes; C017032:asiatic acid
keywords: Umbelopsis isabellina; asiatic acid; biotransformation