Antibacterial Activities of Depsidones from Timorese Endophytic Fungus Corynespora cassiicola against Methicilin and Multidrug-Resistant Bacteria

Chemical investigation of the screened active extract from fungal endophyte Corynespora cassicola associated with medicinal plants Anonna squamosa collected in Timor Island (Indonesia) led to the isolation of four depsidone compounds corynesidone A ( 1 ), B ( 2 ), C ( 3 ) and D ( 4 ). The individual compound was tested for their antibacterial property against multi drug resistant bacteria and for their cytotoxic activity against murine lymphoma (L5178Y) cell line. While compound 1–4 were inactive in the cytotoxic assay, they displayed antibacterial potency toward multi drug resistant clinical isolates Staphylococcus aureus 25697 (MRSA) with MIC value of 16–64 µ g/mL. Moreover, compound 3 was found to be active against Streptococcus pneumonia with MIC value of 32 µ g/mL.