Structures and absolute configurations of phomalones from the coral-associated fungus Parengyodontium album sp. SCSIO 40430

Org Biomol Chem. 2021 Jul 21;19(27):6030-6037. doi: 10.1039/d1ob00869b. Epub 2021 Jun 29.

Abstract

Coral-associated microorganisms are likely to play an important role in host defense by the production of antimicrobials. Six new chromanones, namely, phomalichenones H-M (5, 6, and 8-11), and ten known analogues (1-4, 7, and 12-16) were isolated from the coral-associated fungus Parengyodontium album sp. SCSIO 40430. Their structures were elucidated by comprehensive spectroscopic analyses. In addition, the structure of 8 was confirmed by X-ray crystallographic analysis. Resolution using a chiral column showed that each of the compounds 1-8 was an enantiomeric mixture with variable enantiomeric excess (ee) values. Their absolute configurations were determined by a comparison of the experimental and calculated ECD data and by a modified Mosher's method. A plausible biosynthetic scheme was proposed for the production of 1-16. Compounds 2, 3, 13, and 14 were found to be active against Mycobacterium tuberculosis H37Ra with MIC values of 16-64 μg mL-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Hypocreales*

Supplementary concepts

  • Parengyodontium album