Amphidinin G, a putative biosynthetic precursor of amphidinin A from marine dinoflagellate Amphidinium sp.

Abstract

A new linear polyketide, amphidinin G (1), has been isolated from a symbiotic marine dinoflagellate Amphidinium sp. The planar structure of 1 was established mainly based on the 2D NMR data and the stereochemistry was elucidated by the combination of J-value analysis, modified Mosher’s method, and NMR chemical shift comparison with synthetic analogues. Amphidinin G (1) was expected to be a biosynthetic precursor of amphidinin A (2), a known linear dinoflagellate polyketide. Amphidinin G (1) showed antifungal activity against Trichophyton mentagrophytes.