Isocoumarindole A, a Chlorinated Isocoumarin and Indole Alkaloid Hybrid Metabolite from an Endolichenic Fungus Aspergillus sp.

Author: 

Chen M, Wang R, Zhao W, Yu L, Zhang C, Chang S, Li Y, Zhang T, Xing J, Gan M, Feng F, Si S.
Org Lett. 2019 Feb 20.

Abstract: 

Isocoumarindole A (1), a novel polyketide synthetase-nonribosomal peptide synthetase (PKS-NRPS) hybrid metabolite, was isolated from the endolichenic fungus Aspergillus sp. CPCC 400810. The structure of isocoumarindole A (1) was featured by an unprecedented skeleton containing chlorinated isocoumarin and indole diketopiperazine alkaloid moieties linked by a carbon-carbon bond, which was determined by a combination of spectroscopic analyses, Marfey's method, and calculations of NMR chemical shifts, ECD spectra, and optical rotation values. Isocoumarindole A showed significant cytotoxicity and mild antifungal activities.