[Chemical constituents from root barks of Dictamnus dasycarpus and their cytotoxic activities].

Nineteen compounds, including kihadanin D (1), obacunone (2), kihadanin A (3), kihadanin B (4), kihadanin C (5), limonin (6), evodol (7), fraxinellone (8), furo[2,3-b]quinolin-4-ol (9), preskimmianine (10), ifflaiamine (11), dictamnol (12), naringenin (13), diosmetin (14), wogonin (15), scopoletin (16), cleomiscosin A (17), apocynin (18), and methyl pyroglutamate (19), were isolated from the methanol extract of the root barks of Dictamnus dasycarpus by using various column chromatographies. Their chemical structures were extensively determined on basis of UV, IR, NMR, MS, and CD spectroscopic data analyses. Among them, 1 is a new limonoid, 9 was isolated from plant kingdom for the first time, 11, 13-14 and 17-19 were obtained from the genus Dictamnnus for the first time. Cytotoxicities of compounds 1-18 were tested, and the results indicated that 1 exhibited cytotoxicities against three human cancer cell lines MDA-MB-231, A549 and HT29 with IC₅₈ values of 16.22, 21.72 and 31.06 μmol·L⁻¹, respectively.