Anti-acetylcholinesterase Active Ingredients from Aconitum tanguticum by UPLC-Q-TOF-MS/MS / 中国实验方剂学杂志

ABSTRACT

Objective:To identify the anti-acetylcholinesterase active ingredients in <italic>Aconitum tanguticum</italic>， so as to lay the foundation for finding new anti-Alzheimer's disease （AD） drugs. Method:The anti-acetylcholinesterase active fractions of <italic>A. tanguticum</italic> were screened by the modified Ellman's method， and the chemical composition of the active fraction was analyzed by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry （UPLC-Q-TOF-MS/MS）. The chromatographic separation was performed on an ACQUITY UPLC BEH C₁₈ column （2.1 mm×50 mm， 1.7 μm） with acetonitrile （A）-0.4% ammonia aqueous solution （B） as mobile phase for gradient elution， and the column temperature was set at 30 ℃ with the flow rate of 0.4 mL·min^-1. Phase A of the dichloromethane fraction changed with time as follows：0-3 min， 5%A； 3-7 min， 5%-20%A； 7-11.5 min， 20%-33%A； 11.5-15.5 min， 33%-50%A； 15.5-20.5 min， 50%-80%A； 20.5-23 min， 80%-85%A； 23-25 min， 85%-95%A. Phase A of the <italic>n</italic>-butanol fraction changed with time as follows：0-2 min， 5%A； 2-8 min， 5%-20%A； 8-11 min， 20%-33%A； 11-15 min， 33%-95%A. Mass spectrometry was performed on electrospray ionization， data were collected in positive ion mode， and the detection range was <italic>m</italic>/<italic>z</italic> 100-1 500. Result:Both the dichloromethane and <italic>n</italic>-butanol fractions had a certain inhibitory effect on acetylcholinesterase， their half inhibitory concentration （IC₅₀） values were （64±4.4） mg·L^-1 and （85.7±3.8） mg·L^-1， respectively. By UPLC-Q-TOF-MS/MS analysis， a total of 21 alkaloids were identified from the dichloromethane fraction， and 11 alkaloids were identified from <italic>n</italic>-butanol fraction. Guan-fu base Ⅰ， found in both fractions， was first discovered in <italic>A. tanguticum</italic>. Conclusion:Diterpene alkaloids are the main anti-acetylcholinesterase substances of <italic>A. tanguticum</italic>， which is worth further exploration.