Separation of Two New Prenylated Dihydroflavonoids from Dolichos tenuicaulis (Baker) Craib by High-speed Counter-current Chromatography

The separation and isolation of chemical constituents from Dolichos tenuicaulis (Baker) Craib by high-speed counter-current chromatography (HSCCC) were achieved. The solvent system composed of petroleum ether-ethyl acetate-ethanol-water (1:1.2:1.2:1, v/v) was selected, the upper phase was used as the stationary phase, the lower phase was used as the mobile phase at a flow rate of 2.0 ml min−1 and then the apparatus was controlled at 800 rpm and 30 °C, and the effluent was monitored at 280 nm. Under the optimized conditions, two pure compounds with the amounts of 95.3 mg and 84.5 mg were produced from 400 mg crude sample only in one run, and the chemical structures of the targets were elucidated as (2S)-5,2′, 6′ -trihydroxy-8-prenyl-6,7-(3-prenyl-2,2-dimethyl-1-keone-cyclohexadiene)-flavanone (1) and (2S)-5,2′, 6′ -trihydroxy-8-prenyl-6,7-(3-prenyl-2,2-dimethylpyrano)-3′, 4′ -(2,2-dimethyl-1-keone-cyclohexadiene)-flavanone (2) by physicochemical properties and spectra data. This separation method was simple, and the compounds 1 and 2 were novel compounds.