Flavonoid and cardenolide glycosides and a pentacyclic triterpene from the leaves of Nerium oleander and evaluation of cytotoxicity.

A pentacyclic triterpene, oleanderocioic acid, two flavonoidal glycosides, quercetin-5-O-[α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside and kaempferol-5-O-[α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside, and a cardenolide, oleandigoside, together with 11 known compounds, were isolated from the leaves of Nerium oleander. Their structures were elucidated on the basis of spectroscopic analysis. The growth inhibitory and cytotoxic activities of eight compounds were evaluated against the MCF-7 human breast cancer cell line using a sulforhodamine B assay. Three compounds, oleandrin, odoroside A and B were further assayed using a panel of 57 human cancer cell lines.