Induction of Diverse Bioactive Secondary Metabolites from the Mangrove Endophytic Fungus Trichoderma sp. (Strain 307) by Co-Cultivation with Acinetobacter johnsonii (Strain B2).

Two new sesquiterpenes, microsphaeropsisin B () and C (), and two new de--methyllasiodiplodins, (3, 7)-7-hydroxy-de--methyllasiodiplodin () and (3)-5-oxo-de--methyllasiodiplodin (), together with one new natural product () and twelve known compounds (, -), were isolated from the co-cultivation of mangrove endophytic fungus sp. 307 and aquatic pathogenic bacterium B2. Their structures, including absolute configurations, were elucidated by extensive analysis of spectroscopic data, electronic circular dichroism, Mo₂(AcO)₄-induced circular dichroism, and comparison with reported data. All of the isolated compounds were tested for their α-glucosidase inhibitory activity and cytotoxicity. New compounds and exhibited potent α-glucosidase inhibitory activity with IC values of 25.8 and 54.6 µM, respectively, which were more potent than the positive control (acarbose, IC = 703.8 µM). The good results of the tested bioactivity allowed us to explore α-glucosidase inhibitors in lasiodiplodins.