Pestalotiopols E–J, Six New Polyketide Derivatives from a Marine Derived Fungus <i>Pestalotiopsis</i> sp. SWMU-WZ04-1

Abstract

Chemical epigenetic cultivation of the sponge-derived fungus Pestalotiopsis sp. SWMU-WZ04-1 contributed to the identification of twelve polyketide derivatives, including six new pestalotiopols E–J (1–6) and six known analogues (7–12). Their gross structures were deduced from 1D/2D NMR and HRESIMS spectroscopic data, and their absolute configurations were further established by circular dichroism (CD) Cotton effects and the modified Mosher’s method. In the bioassay, the cytotoxic and antibacterial activities of all compounds were evaluated. Chlorinated benzophenone derivatives 7 and 8 exhibited inhibitory effects on Staphylococcus aureus and Bacillus subtilis, with MIC values varying from 3.0 to 50 μg/mL. In addition, these two compounds were cytotoxic to four types of human cancer cells, with IC50 values of 16.2~83.6 μM. The result showed that compound 7 had the probability of being developed into a lead drug with antibacterial ability.

Keywords

• <i>Pestalotiopsis</i> sp.
• polyketide
• sponge-derived fungus
• antibacterial activity
• cytotoxicity