Abstract
3, 3', 4, 5'-Tetrahydroxystilbene (1) isolated from the heartwood of Cassia garrettiana CRAIB. showed a broad spectrum of physiological activities, including antifungal, phytogrowthinhibitory and ichthyotoxic activities. Firstly. 1 showed antifungal activity ; the minimal growthinhibitory concentration (MIC) was 25 μg/ml against Penicillium citrinum and Rhizopus nigricans. Secondly, 1 showed rather strong inhibitory activity on the growth of five plant species at a concentration of 500ppm. Thirdly. 1 had ichthyotoxic activity. The median tolerance limit (TLm) at 48h was 26.5ppm in Oryzias latipes TEMMINCK et SCHLEGEL and 31.5 ppm in Carassius auratus LINNE. Studies were made on the activities of derivatives of 1, i.e., 3, 3', 4, 5'-tetrahydroxystilbenetetraacetate (2), 3, 3', 4, 5'-tetrahydroxystilbene-tetramethyl ether (3), and 3, 3', 4, 5'-tetrahydroxybibenzyl (4). The activities of these derivatives, however, were lower than those of 1, except for the phytogrowth-inhibitory and ichthyotoxic activities of 4. It is clear that for antifungal activity, both the hydroxyl groups attached to the benzene rings and the trans-olefin structure are necessary, while for the phytogrowth-inhibitory and ichthyotoxic activities, only the hydroxyl groups attached to the benzene rings are necessary.
