Metabolomics-Guided Discovery of Bipolarolides H−O, New Ophiobolin-Type Sesterterpenes with Antibacterial Activity from the Marine-Derived Fungus Uzbekistanica storfjordensis sp. nov.

Abstract

A marine-derived Pleosporales fungus, Uzbekistanica storfjordensis, was isolated from driftwood and described as a new species. The fungus was cultivated in liquid media and a molecular networking-driven approach was used to identify potential new secondary metabolites. The targeted compounds were isolated using preparative HPLC-MS, and through extensive spectroscopic analysis, eight new ophiobolin-type sesterterpenes, bipolarolides H–O (1–8), were identified. The absolute configurations of the compounds were determined by ECD assessment. Bipolarolide L (5), M (6), and O (8) exhibited inhibitory activity against Streptococcus agalactiae with MIC values of 86, 66, and 64 μM, respectively.