Author : Ng Kim Nee

Summary : Chemical and cytotoxic studies were carried out on two plant species, Calophyllum mucigerum (Guttiferae) and Ploiarium alternifolium (Theaceae). The chemical investigations covered anthraquinones, triterpenes, xanthone and coumarins. These compounds were isolated using common chromatographic techniques and HPLC and identified using spectroscopic methods including 2-D NMR, GCMS, MS, IR and UV. Ploiarium alternifolium provided emodin, ploiariquinone A, 1, 8-dihydroxy-3-methyl-6-methoxy-anthraquinone, 3 beta-benzoyloxyolean-11-en-13 beta, 28-olide and euxanmodin C. Emodin and 1, 8-dihydroxy-3-methyl-6-methoxy-anthraquinone have not been reported from Ploairium alternifolium. Calophyllum mucigerum gave the common steroidal triterpenes friedelin and stigmasterol, a prenylated xanthone cudraxanthone C and two new coumarins mucigerin I and mucigerin II. The crude n-hexane, ethyl acetate and ethanol stem bark extracts of both plants were screened for their larvicidal activity against the larvae of Aedes aegypti. The crude n-hexane, ethyl acetate and ethanol extracts for both of the plants were susceptible to the larvae of Aedes aegypti with LC50 values of 95.0 ml, 129.4 ml and 131.6 ml, respectively for Ploiarium alternifolium whereas 87.9 ml, 138.5 ml and 147.4 ml respectively for Calophyllum mucigerum. Larvicidal activity on the pure compound, emodin gave an LC50 value of 2.79 ml.