New azaphilone, isocoumarin and α-pyrone derivatives from the marine-derived gut fungus Paraphaeosphaeria sp. XZD2-1. (April 2020)

• Record Type: Journal Article
• Authors: Sun, Jiaolu; Zhang, Haojian; Ding, Wanjing; Zheng, Dao-qiong; Wang, Pin-mei; Xu, Jinzhong
• Is Part Of: Phytochemistry letters. Volume 36(2020)
• Page Start: 1
• Page End: 6
• Publication Date: 2020-04
• Subjects: Azaphilones -- Isocoumarins -- α-Pyrone derivatives -- Marine-derived fungi -- Paraphaeosphaeria sp.; Botanical chemistry -- Periodicals; Chimie végétale -- Périodiques; 572.205
• DOI: 10.1016/j.phytol.2019.12.010
• Languages: English
• ISSNs: 1874-3900

Abstract

Graphical abstract: Six new compounds including two azaphilones, lunatoic acids D–E (1, 2 ), three isocoumarins, lunatinins B–D (3 -5 ), and one α-pyrone derivative, lunatinin E (6 ), as well as four known ones, lunatoic acid A (7 ), lunatinin (8 ), penicipyran D (9 ) and chaetoquadrin F (10 ) were isolated from the rice medium of the gut fungus Paraphaeosphaeria sp. XZD2-1. Abstract: Six new compounds including two azaphilones, lunatoic acids D–E (1, 2 ), three isocoumarins, lunatinins B–D (3 -5 ), and one α-pyrone derivative, lunatinin E (6 ), as well as four known ones, lunatoic acid A (7 ), lunatinin (8 ), penicipyran D (9 ) and chaetoquadrin F (10 ) were isolated from the rice medium of the gut fungus Paraphaeosphaeria sp. XZD2-1. Their planar structures were elucidated by analysis of 1D and 2D NMR as well as HRESIMS spectroscopic data. The absolute configurations of compounds 1 -3 were assigned by experimental and calculated ECD data and an ester hydrolysis reaction. Compounds 4 and 5 were a pair of enantiomeric excess mixture. Structure of compound 6 was further confirmed by comparing optical rotation with known compounds according to literature. The antimicrobial activity and cytotoxicity of compounds 1 -10 were examined. Highlights: The first report about lunatoic acids from a marine-derived Paraphaeosphaeria sp. fungus. Four new isocoumarin and α-pyrone derivatives from the fungus. Experimental and calculated ECD were used to elucidate the absolute configurations of new compounds. The antimicrobial activity and cytotoxicity of isolated compounds were examined.