In vitro antimycotic activity of chemical constituents from Dipterocarpus verrucosus, Dipterocarpus cornutus and Dipterocarpus crinitus against opportunistic filamentous fungi

This paper will discuss, in vitroinvestigation of chemical constituents extracted from the stem bark of Dipterocarpus verrucosus, Dipterocarpus crinitus and Dipterocarpuscornutusagainst opportunistic filamentous fungi.In this research, 17 compounds comprised of twelve oligostilbenoids, (-)--viniferin ,(-)-laevifonol,(-)-hopeaphenol,(-)-isohopeaphenol, vaticanol B, diptoindonesin E, hemsleyanol D, davidiol A, resveratrol, ampelopsin A, ampelopsin F,together with three other phenolic; gallic acid derivative, (-)-bergenin, scopoletin and 4-methoxygallocathecin and also two terpene; β-sitosterol and β-sitosterol glucoside have been isolated. In this study, the crude extracts and isolated compounds were evaluated regarding to their antifungal activity; in terms of MIC, MFC and germination assay against pathogenic fungi strains, namely Aspergillus flavus (AF), Aspergillus oligosporus (AO),Rhizophus oryzae (RO)andFusarium oxysporum (FO) using Clinical and Laboratory Standard Institute (CLSI) methods. The MIC of crude extracts and isolated compounds against all fungi ranged from 3.8 -500 μg/mL. F. oxysporumshows the most sensitive microorganisms on crude extract: D. verrucosus, D. cornutusand isolated compound: ε-viniferin with MIC of 3.8 μg/mL. The MIC was lower compared to amphotericin B (4 μg/ml). The strain was killed at the MFC of 31.3, 31.3 and 15.6 μg/mL respectively, as compared to amphotericin B (8 μg/mL). Compounds: resveratrol, laevifonol, ε-viniferin, ampelopsin F, vaticanol B, vaticanol A, isomer of hopeaphenol and isohopeaphenol, β-sitosterol and β-sitosterolglucoside possessed an inhibitory activity on the conidial germination of F. oxysporumat the concentration of 4× MIC. On top of that, D. cornutus, ampelopsin A and hemsleyanol D possessed a complete sterility atthe concentration of 2×MIC while D.verrucosusachieved its inhibitory activity at 1× MIC. To the best of our study, there is no data discussing the inhibition of conidial germination of filamentous fungi using the tested compounds and crudes tested.