In the course of our efforts to search new secondary metabolites from marine-derived fungi, one new hexylitaconic acid derivative, 3-(5-methoxycarbonylpentyl)-4-methylfuran-2,5-dione (1), and two dimeric analogues asperwelwinates A and B (2 and 3), together with ten known compounds, asperitaconic acid C (4), kotanin (5) and orlandin (6), desertorin B (7), fonsecinone A (8), aurasperone A (9), asperpyrones B and C (10 and 11), aspernigrin B (12), and pyrophen (13), were isolated from a strain of Aspergillus welwitschiae CUGBMF180262. The structures of compounds 1-3 were determined by detailed analysis of HRMS, and 1D/2D NMR experiments, while the absolute configurations of 2 and 3 were determined by comparison of experimental and calculated electronic circular dichroism spectra. 2 and 3 were first reported dimeric hexylitaconic acid derivatives. Compounds 8, 9 and 11 showed moderate antibacterial activities against Helicobacter pylori with minimum inhibitory concentration (MIC) values of 16 μg/mL.
Keywords: Marine-derived Aspergillus welwitschiae; anti-Helicobacter pylori; dimeric hexylitaconic acid.