Studies On Acetylcholinesterase Inhibitory Activities Of Chemical Constituents From Chimonanthus Praecox Leaves

Chimonanthus praecox, Calycanthaceae(Calycanthaceae) is a Chinese deciduous shrub, growing in Zhejiang, Jiangxi, Hubei, Hunan, Shanxi and Yunnan provinces of China. It is a traditional Chinese medicine, with a variety of pharmacological activities. A lot of studies indicated that C. praecox has acetylcholinesterase inhibitory activity and its extraction has potential of future acetylcholinesterase inhibiting drugs.In this study, we adopted ultrasonic-assisted extraction in room temperature with organic solvents and organic solvent extraction, then we got petroleum ether extract,ethyl acetate extract, n-Buoh extract and water extract. We adopted improved Ellman method to test the antiacetylcholinesterase activity of petroleum ether extract, ethyl acetate extract and n-Buoh extract of C. praecox leaves, with the result that the three parts all have the inhibitory activity, but the biggest one is ethyl acetate extract, its IC50 is 6.809 mg/mL.In this paper, the petroleum ether extracts from leaves of C. praecox were analyzed by gas chromatography-mass spectrometry. At last, 54 compounds were separated and identified which accounted for 84.524% of total extracts from the petroleum ether extracts. And the highest content is ester compound(64.243%).To study the material basis and mechanism of C. praecox leaves acetylcholinesterase inhibitory activity furtherly, the research use column chromatography method and sephadex gel column to study C. praecox leaves and ethanol extract Parts of ethyl acetate systematically and identificate structurally,eleven compounds(1-11) were isolated, according to compounds of the physical and chemical properties and spectral characteristics, 7 compounds were identified which named: β-sitosterol(1), isofraxidin(2), quercetin(3), kaempferol(4), stigmasterol(6),scopoletin(7), 6,7-dimethoxy coumarin(8) 。 Among them, 2(IC50=23.37 μM), 7(IC50=18.86 μM) and 8(IC50=33.16 μM) show good inhibition effects on AChE activity.This study provides the experimental and theoretical basis to the further study on leaves of C. praecox.