New bianthrone-type dimeric derivatives isolated from a mangrove-derived fungus Hamigera paravellanea GXIMD 03119.

Chemical investigation of the mangrove-derived fungus Hamigera paravellanea GXIMD 03119 afforded two previously undescribed bianthrone-type dimers, emodin bianthrone C (1) and emodin bianthrone D (2), together with three known metabolites (3-5). The structures of two new compounds were established through detailed analysis of NMR spectroscopic data and HRESIMS evidence. The isolated compounds were evaluated for antibacterial activity, and compounds 1 and 2 inhibited Staphylococcus aureus, each with an MIC value of 7.81 μg/mL. These results add new members to the emodin bianthrone family and further support mangrove-associated fungi as productive sources of bioactive secondary metabolites.