Phomopsinones A-D: Four New Pyrenocines from Endophytic Fungus Phomopsis sp.

The structural elucidation of the compounds isolated from the endophytic Phomopsis sp. revealed phomopsinones AD (14), four new a-pyrone derivatives. Three known compounds were also isolated, namely two phomosines, phomosine A (5) and phomosine C (6), and ergosterol (7). The structures of these compounds were determined by spectroscopic analysis (1H, 13C, 1H1H COSY, HMQC, HMBC, and ROESY NMR, and mass spectrometry), supported by molecular modeling. The absolute configurations of the new compounds 14 were determined by circular dichroism spectroscopy and TDDFT calculations. Preliminary studies indicated that compounds 1 and 4 show strong and good antifungal activity, respectively. Similarly, compounds 2 and 3 showed good antifungal and moderate antibacterial activities as well as antialgal activities.