The chemical constituents of the water extraction of the aerial parts of Isodon henryi were investigated by various chromatographic methods including D-101 macroporous adsorptive resins,silica gel,sephadex LH-20,and semi-preparative HPLC. As a result,ten compounds were separated and purified. By analyses of the UV,IR,MS,NMR spectra,their structures were determined as rabdosinate( 1),lasiokaurin( 2),epinodosinol( 3),rabdosichuanin C( 4),epinodosin( 5),hebeirubescensin k( 6),rubescensin C( 7),enmenol( 8),oridonin( 9),and enmenol-1-β-glucoside( 10). Compounds 1-8 and 10 were isolated from I. henryi for the first time. Compounds 2 and 9 showed inhibitory effects against four tumor cells,with IC50 values of 2. 25-9. 32 μmol·L-1.
Keywords: Isodon henryi; cytotoxic; diterpenes; structural identification.