Trichodermatides A-D, Novel Polyketides from the Marine-Derived Fungus Trichoderma reesei.

Four new polyketide derivatives, Trichodermatides A−D (1−4) were isolated from the marine-derived fungus Trichoderma reesei. Trichodermatide A (1) is an unprecedented example of a polyketide with a ketal-containing pentacyclic skeleton. The chemical structures and absolute configurations of compounds 1−4 were elucidated by extensive spectroscopic methods, especially 2D NMR and CD spectral analysis, and supported by their proposed biosynthesis pathway. The cytotoxicity of 1−4 was evaluated against A375-S2 human melanoma cell line.