(±)-Nigronetides A−D and Nigronetides E−H, Complex Polyketides Produced by the Marine-Derived Fungus Nigrograna sp. M13

Abstract

Abstract (±)-Nigronetides A−D (1−4) and nigronetides E−H (5−8), polyketides with complex carbon skeletons, were isolated from cultures of the marine-derived fungus Nigrograna sp. M13, presenting three novel carbon skeletons. While the planar structures and relative configuration of (±)-nigronetides A−D (1−4) were established by analysis of spectroscopic data, the absolute configuration of nigronetides E−H (5−8) was assigned using a combination of analysis of NOESY data, quantum chemical NMR calculations, as well as by comparison between experimental and calculated electronic circular dichroism (ECD) spectra. (±)-Nigronetides A−D (1−4) were isolated as scalemic mixtures of an almost identical ratio between enantiomers. Compounds 1−8 were inactive in antiplasmodial assays against the Plasmodium falciparum 3D7 strain as well as in cytotoxicity assays against several cancer cell lines.

The authors' abstract, as published at the source. Journal of Natural Products, 2026 · DOI ↗