| Through bioactivity-directed fractionation, six cytotoxic constituents have been characterized from the bark of Plumeria rubra L. collected in Bandung, Java, Indonesia. Three iridoids, fulvoplumierin, allamcin, and allamandin, as well as 2,5-dimethoxy-p-benzoquinone, were found to be active constituents of the P. rubra petroleum ether- and chloroform-soluble extracts. Cytotoxic compounds isolated from the water-soluble extract of the bark were the iridoid, plumericin, and the lignan, liriodendrin. Five additional iridoids, 15-demethylplumieride, plumieride, ;Five cytotoxic constituents have been isolated from the roots of Eurycoma longifolia Jack, collected in Samarinda, Indonesia. For canthin-6-one alkaloids, namely, 9-methoxycanthin-6-one, 9-methoxycanthin-6-one-N-oxide, 9-hydroxycanthin-6-one, 9-hydroxy-canthin-6-one-N-oxide, and one quassinoid, eurycomanone, were found to be cytotoxic principles. Two additional isolates, ;The structures of the isolates from P. rubra and E. longifolia were identified or elucidated through the use of some modern nmr technique, in addition to chemical methods. |
