Abstract
A new compound, 3, 4-O-isopropylidene-3, 3', 4, 5'-tetrahydroxystilbene (I), chemically derived from 3, 3', 4, 5'-tetrahydroxystilbene (II) showed strong antifungal activity, ichthyotoxicity, coronary vasodilator action on the isolated guinea-pig heart and a hypotensive effect on rats. These activities of I were much stronger than those of the original substance (II). As regards antifungal activity, the minimal growth inhibitory concentrations (MIC) of I for Trichophyton mentagrophytes and Fusarium oxysporum f. sp. lycopersici were 6 and 1μg/ml, respectively. As regards ichthyotoxic activity, the median tolerance limit (TLm) at 48 h was 14.0 ppm in Oryzias latipes TEMMINCK et SCHLEGEL. Compound (I) also had strong coronary vasodilator action on guinea-pig heart in vitro ; the ED50 value was 4.5μg/heart. Finally, I showed a strong hypotensive effect on rats (-43.0±5.2mmHg, 10mg/kg i.v.).
