Abstract
Context: Endophytic fungi associated with medicinal plants represent a reservoir of novel bioactive compounds. Aims: To investigate the antimicrobial and cytotoxicity of methanolic extracts of endophytic fungi from ginger (Zingiber officinale Roscoe), as well as identification of the talented fungus and LC/MS-MS profile of its secondary metabolites. Methods: The pure fungal isolates were cultivated on rice media and extracted with EtOAc. The resulting fungal extracts were subjected to antimicrobial and cytotoxicity tests. The talented fungus, capable of producing the most active extract, was further identified for its species level, and its extract was analyzed through LC-MS/MS. Results: Three endophytic fungal strains (ZO-L2-3, ZO-L2-4, and ZO-Rh2-1) were isolated. In the antimicrobial assay, fungal extract ZO-L2-4 showed the highest inhibition against Staphylococcus aureus ATCC 6538 with an MIC value of 15.6 µg/mL. It also had the strongest toxicity, with an LC50 value of 190.6 µg/mL, in the toxicity screening against brine shrimp larvae. Further, a cytotoxicity test against MCF-7 cells showed that ZO-L2-4 extract had the strongest cytotoxicity with an IC50 value of 7.0 µg/mL. The fungal isolate ZO-L2-4 was later identified as Fusarium proliferatum. Furthermore, LC-MS/MS analysis showed a major peak at tR of 7.85 minutes in the methanolic extract of ZO-L2-4, attributed to the molecular formula of C13H16NO5 and tentatively assigned as 8-O-methylbostrycoidin. Conclusions: Methanolic extract of endophytic F. proliferatum ZO-L2-4 showed the most prominent antimicrobial and cytotoxicity in this study. Thus, an investigation into bioactive compounds from F. proliferatum ZO-L2-4 and their mode of action is encouraging for further study.