Isolation of anticomplementary substances from Cucurbita moschata Duch

Abstract

Chloroform and ethyl acetate extracts of the edible part of Cucurbita moschata Duch, which is commonly used as an oriental medicine as well as a popular food source, showed significant anticomplementary activities on the classical pathway of the complement system. Bioassay-guided chromatographic separation using silica gel, Sephadex LH-20, octadecyl silica gel, thin layer chromatography, and high performance liquid chromatography was performed to isolate the anticomplementary substances. Among the isolated substances, apigenin, phytosterols, and mixture of fatty acids, which were identified by nuclear magnetic resonance and gas chromatography-mass spectrometry, presented the strongest activities. Especially, phytosterols and mixture of saturated fatty acids isolated from the ethyl acetate extracts had 0.74 and 0.67 mg/ml as IC50, respectively, indicating that the ethyl acetate extraction is the best way to isolate the anticomplementary substances from Cucurbita moschata Duch.