Cytotoxic terpenoid and immunosuppressive phenolic glycosides from the root bark of Dicatamnus dasycarpus

Five new compounds, two degraded terpene glycosides, dasycarpusides A and B (1, 2), and three phenolic glycosides, 2-methoxy-4-hydroxymethylphenol 1-O-alpha-rhamnopyranosyl-(1"-->6')-beta-glucopyranoside (3), 2-methoxy-4-acetylphenol 1-o-alpha-rhamnopyranosyl-(1"-->6')-beta-glucopyranoside (4), and 2-methoxy-4-(8-hydroxyethyl)-phenol 1-O-alpha-rhamnopyranosyl-(1"-->6')-beta-glucopyranoside (5), were isolated from the water-soluble constituents of the root bark of Dictamnus dasycarpus Turcz. (Rutaceae). Their structures were elucidated by spectroscopic analysis and chemical evidence. Moreover, it was found that dasycarpuside A (1) showed weak cytotoxic activity against A-549 (human lung adenocarcinoma) cell line, while 4 and 5 showed more remarkable activity of inhibiting the proliferation of T-cells in vitro.