新疆沙枣叶提取物对春尺蠖多酚氧化酶的抑制作用  

Inhibitory effects of two compounds extracted from leaves of Elaeagnus oxycarpa Schlechtend in Xinjiang onpolyphenol oxidase of larva Apochemia cinerarius Ersch

作　　者：徐彤 郑旭东 崔羽歆 王俊 朱慧玲 付建红 姚雪丹 XU Tong;ZHENG Xudong;CUI Yuxin;WANG Jun;ZHU Huiling;FU Jianhong;YAO Xuedan(Xinjiang Key Laboratory of Special Species Conservation and Regulatory Biology,Key Laboratory of Species Diversity Application and Control in Xinjiang,College of Life Science,Xinjiang Normal University,Urumqi 830054,China)

机构地区：[1]新疆师范大学生命科学学院新疆特殊环境物种多样性应用与调控重点实验室新疆特殊环境物种保护与调控生物学实验室,新疆乌鲁木齐830054

出　　处：《生物加工过程》2020年第3期340-345,共6页Chinese Journal of Bioprocess Engineering

基　　金：新疆维吾尔自治区自然科学基金(2016D01A054)。

摘　　要：多酚氧化酶在昆虫的变态发育和免疫防御中起着非常重要的作用,可作为害虫控制的一个重要作用靶标。采用40%饱和度硫酸铵沉淀和Sephadex G-100凝胶过滤等步骤,对产自于乌鲁木齐的春尺蠖幼虫多酚氧化酶进行分离,并研究其酶学性质。结果表明:多酚氧化酶的比酶活为617.21 U/mg,是粗酶液的6.06倍;该酶对焦性没食子酸、邻苯二酚和L-多巴的K m值分别为6.45、1.11和1.3 mmol/L;在pH 6.5、25℃时,多酚氧化酶活性最高;当温度高于45℃时,随着保温时间的延长,酶活力下降明显。采用中压色谱和C18反相制备型色谱技术对尖果沙枣叶乙醇提取物进行分离,得到6个化合物,鉴定了其中2个化合物;将这2个化合物用于多酚氧化酶的抑制实验,结果表明分离到的化合物6和化合物7均显示出抑制活性,IC 50值约为0.125 mg/mL。Polyphenol oxidase plays important roles in metamorphosis development and immune defense of insects,then it can be as an important target against the pest control.The polyphenol oxidase(PO)from Apochemia cinerarius Ersch larvae in Urumqi was partially purified by 40%saturated(NH 4)2 SO 4 and sephadex G-100 gel filtration and enzymatic properties were studied.The results showed that the specific activity of PO was 617.21 U/mg and PO was purified 6.06-fold of the crude enzyme.The kinetic parameters for the oxidation of pyrogallic acid,catechol and L-dopamine(L-DOPA)by the PO were 6.45,1.11 and 1.3 mmol/L,respectively.The optimum pH was 6.5 and the best temperature was 25℃for the tested PO.The enzyme activity decreased obviously with the prolongation of holding time above 45℃.By medium pressure chromatography(MPLC)and C18-reversed phase chromatography,6 compounds were isolated from the ethanol extracts of Elaeagnus oxycarpa Schlechtend leaves,2 of which were identified.The inhibition of PO showed that the isolated compounds 6 and 7 showed inhibition activity and the inhibitor concentrations of leading to 50%activity lost(IC 50)were estimated to be 0.125 mg/mL for the two compounds.

关 键 词：尖果沙枣 春尺蠖 多酚氧化酶 酶学性质 抑制剂 

分 类 号：Q554[生物学—生物化学]