番茄碱的制备及其对乙酰胆碱酯酶的抑制作用  

Preparation of Tomatidine and Its Inhibitory Effect on Acetylcholinesterase

作　　者：姜晓霞 朱艳雯 周丽丽 赵楠 刘玲[1] 岳喜庆[1] 白冰[1] JIANG Xiaoxia;ZHU Yanwen;ZHOU Lili;ZHAO Nan;LIU Ling;YUE Xiqing;BAI Bing(College of Food Science,Shenyang Agricultural University,Shenyang 110866,China)

机构地区：[1]沈阳农业大学食品学院,辽宁沈阳110866

出　　处：《食品科学》2022年第1期14-21,共8页Food Science

基　　金：国家自然科学基金面上项目(31571799);“十三五”国家重点研发计划重点专项(2018YFC1603703)。

摘　　要：本实验采用超高效液相色谱-四极杆飞行时间质谱(ultra-performance liquid chromatography-quadrupole timeof-flight mass spectrometry,UPLC-QTOF-MS)和核磁共振(nuclear magnetic resonance spectroscopy,NMR)氢谱、碳谱鉴定从番茄叶中提取并纯化的番茄碱;利用紫外光谱法、分子荧光光谱法和分子对接技术研究番茄碱对乙酰胆碱酯酶(acetylcholinesterase,AChE)活性的影响,同时探究番茄碱与AChE的结合方式,为番茄碱的神经保护机制提供理论依据。结果表明,纯化产物经UPLC-QTOF-MS和^(1)H NMR、^(13)C NMR分析确定为番茄碱。利用紫外光谱法检测出番茄碱可部分抑制AChE的催化活性,并且番茄碱对AChE的抑制作用为竞争性抑制。分子荧光光谱显示,经番茄碱处理的AChE蛋白在340 nm波长处的发射荧光强度下降,并出现红移现象;Autodock分子对接技术分析结果显示,番茄碱与AChE蛋白中的Ser293、Phe295、Phe338、Phe297、Ser125、Gly121、Ser203、Glu202、Gly120、His447、Gly448、Ile451、Trp86、Tyr124、Tyr337、Tyr341、Ile294形成疏水相互作用并与其中的Trp86形成氢键,表明AChE的微环境发生了变化,竞争性地干扰了底物乙酰胆碱与AChE的结合。因此,番茄碱是通过形成氢键和疏水作用的方式抑制AChE活性。Tomatidine purified from tomato leaves was identified by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-QTOF-MS)and ^(1)H and ^(13)C nuclear magnetic resonance(NMR).The effect of tomatidine on the activity of acetylcholinesterase was evaluated by ultraviolet(UV)spectroscopy,molecular fluorescence spectroscopy and molecular docking,and the mode of combination between tomatidine and acetylcholinesterase was explored.The results showed that the purified product was identified as tomatidine.It partially inhibited acetylcholinesterase(AChE)in a competitive manner.The molecular fluorescence spectra showed that tomatidine decreased the fluorescence emission intensity of AChE at 340 nm and led to a red shift.Molecular docking with Autodock revealed that tomatidine hydrophobically interacted with Ser293,Phe295,Phe338,Phe297,Ser125,Gly121,Ser203,Glu202,Gly120,His447,Gly448,Ile451,Trp86,Tyr124,Tyr337,Tyr341 and Ile294 in AChE,and formed hydrogen bonds with Trp86,indicating that the microenvironment of AChE was changed,competitively interfering with the binding of the substrate acetylcholine to AChE.Therefore,tomatidine can inhibit the activity of AChE by forming hydrogen bonds as well as through hydrophobic interactions.

关 键 词：番茄碱 乙酰胆碱酯酶 酶活性 竞争性抑制 分子对接 

分 类 号：TS201.2[轻工技术与工程—食品科学]