ABSTRACT
Four flavonoids including apigenin-7,4'-dimethylether, genkwanin, quercetin, and kaempferol were isolated in a preparative or semi-preparative scale from the leaves of wild Aquilaria sinensis using an improved preparative high-speed counter-current chromatography apparatus. The separations were performed with a two-phase solvent system composed of hexane-ethyl acetate, methanol-water at suitable volume ratios. The obtained fractions were analyzed by HPLC, and the identification of each target compound was carried out by ESI-MS and NMR. The yields of the above four target flavonoids were 4.7, 10.0, 11.0 and 4.4%, respectively. All these four flavonoids exhibited nitrite scavenging activities with the clearance rate of 12.40 ± 0.20%, 5.84 ± 0.03%, 28.10 ± 0.17% and 5.19 ± 0.11%, respectively. Quercetin was originally isolated from the Thymelaeaceae family, while kaempferol was isolated from the Aquilaria genus for the first time. In cytotoxicity test these two flavonoids exhibited moderate inhibitory activities against HepG2 cells with the IC50 values of 12.54 ± 1.37 and 38.63 ± 4.05 µM, respectively.
Subject(s)
Countercurrent Distribution/methods , Flavonoids/analysis , Flavonoids/isolation & purification , Thymelaeaceae/chemistry , Antineoplastic Agents/analysis , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , Antineoplastic Agents/pharmacology , Cell Survival/drug effects , Flavonoids/chemistry , Flavonoids/pharmacology , Hep G2 Cells , Humans , Plant Leaves/chemistryABSTRACT
Objective: To develop a method for separation and purification of triterpenoids from Helicteres angustifolia by highspeed countercurrent chromatography( HSCCC). Methods: The ethyl acetate extract of Helicteres angustifolia were separated by two-step HSCCC. The structures of the target compounds were identified by ESI-MS and1H-NMR and characterized by FTIR. Results: Six compounds were isolated and prepared from ethyl acetate extract of Helicteres angustifolia,and identified as methyl helicterilate( 1),methyl helicterate( 2),helicterilic acid( 3),helicteric acid( 4),betulic acid( 5),oleanolic acid( 6). The purity of the chemical constituents were determined by HPLC,and the mass fraction was more than 95. 0%,respectively. Conclusion: This method is suitable for the separation and preparation of triterpenoids from Helicteres angustifolia,which is rapid,high purity and high yield.
