Extraction, Purification and Antiradical Activities of Alpinetin and Cardamomin from Alpinia katsumadai Hayata

Abstract

Alpinetin and cardamomin are the major effective ingredients, which exist in Alpinia katsumadai Hayata and have strong activity in inhibiting platelet aggregation and tumor formation, antiinflammatory and antibacterial activities. Using orthogonal experiments L₁₆ (4³), alpinetin and cardamomin were extracted from Alpinia katsumadai Hayata by microwave-assisted extraction. Then, high-speed counter-current chromatography (HSCCC) was used to separate and isolate of alpinetin and cardamomin by two-phase solvent system of n-hexane-ethyl acetate-ethanol-water (5:6:5:5, v/v) in one-step separation. The lower phase was used as the mobile phase in the head-to-tail elution mode. From 158.4 mg of the crude extract, 14.47 mg of alpinetin and 1.72 mg of cardamomin with purities of 99.01 and 97.71 % were obtained, respectively. They were identified by melting points, UV, IR, ¹H and ¹³C NMR. Furthermore, they were tested for 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals scavenging activities. The results showed that alpinetin had strong DPPH free radicals scavenging activities.