Isolation, structure elucidation and biological activity of metabolites from Sch-642305-producing endophytic fungus Phomopsis sp. CMU-LMA

• Main Authors: Adelin E., Servy C., Cortial S., Levaique H., Martin M.-T., Retailleau P., Le Goff G., Bussaban B., Lumyong S., Ouazzani J.
• Format: Article
• Language: English
• Published: 2014
• Online Access: http://www.scopus.com/inward/record.url?eid=2-s2.0-80054953379&partnerID=40&md5=5d21cc78d4966a9c4c0ce3a86163bc8c; http://cmuir.cmu.ac.th/handle/6653943832/6413
• Institution: Chiang Mai University

Eight polyketide compounds were isolated from the cultivation broth of Phomopsis sp. CMU-LMA. We have recently described LMA-P1, a bicyclic 10-membered macrolide, obtained as a bioconversion derivative of Sch-642305, the major compound isolated in this study. Benquinol is the ethyl ester derivative of the 13-dihydroxytetradeca-2,4,8-trienoic acid produced by Valsa ambiens. This compound is concomitantly produced with the 6,13-dihydroxytetradeca-2,4,8- trienoic acid (DHTTA) previously isolated from Mycosphaerella rubella. The absolute configuration of the new compound, (2R,3R,4S,5R)-3-hydroxy-2,4- dimethyl-5-[(S,Z)-3-methylpentenyl]-tetrahydro-pyranone LMA-P2 was confirmed by X-ray crystallography. The δ-lactone 2,3-dihydroxytetradecan-5-olide (DHTO) was previously isolated from Seiridium unicorne. This compound may form through the cyclization of the methyl-2,3,5-trihydroxytridecanoate LMA-P3, a new linear polyketide isolated in this study. Benquoine, a new 14-membered lactone generated from the cyclization of benquinol, is proposed as the key precursor for the biosynthesis of Sch-642305. Antimicrobial activity and cancer cell viability inhibition by the new compounds were investigated. Benquoine exhibits antimicrobial activity against Gram positive bacteria, and cytotoxicity against HCT-116 cancer cell line. © 2011 Elsevier Ltd. All rights reserved.