Isolation and identification of highly active anticholinesterase ingredients from fermented soybean products

Inhibitory activities of ethanol extracts from seven fermented soybean products, including douchi, sufu, stinky tofu, to acetylcholinesterase were determined, and crude extract from Yongchuan douchi, which showed the strongest inhibitory effect, was further extracted systematically. Highly active anticholinesterase ingredients were mainly found in petroleum ether extracts; after multistep column chromatography, three compounds were purified finally with high-speed countercurrent chromatography. By their spectral data of MS, 1H-NMR, and 13C-NMR, three compounds were identified as genistein, daidzein, and kaempferol, whose further research could lay foundation for research and development of new drugs and foods against Alzheimer’s disease.