【作者】 李珺； 张英侠；

【Author】 LI Jun,ZHANG Ying-xia (School of Chemical Biology and Phamaceutical Sciences, Capital Medical University, Beijing 100069, China)

【机构】 首都医科大学化学生物学与药学院；

【摘要】 目的元宝枫叶中含有多种生物活性成分,如黄酮、强心甙、绿原酸、甾体、鞣质、多糖等。我们的酶动力学实验研究表明元宝枫叶对脂肪酸合成酶（FAS）有强抑制作用,该酶是治疗癌症的新的潜在靶部位,抑制FAS有可能成为一条新的化疗途径。通过高效液相色谱（HPLC）分离分析,表明元宝枫叶含有游离的没食子酸和大量的水解没食子酸,从基础研究的角度,可探索元宝枫中的生物活性成分的抑癌作用机理;并且为开发中国广博的天然产物资源提供了新的思路。元宝枫中黄酮类化合物含量较高。研究元宝枫叶中主成分之一的黄酮类化合物是否与抑制FAS存在一定的相关性,可以促进元宝枫叶中黄酮的分离和利用。方法采用高效液相色谱法在Diamonsil C18色谱柱（5μm,4.6×250mm）,流动相:甲醇-0.025mol/L磷酸水溶液（15:85）;流速:1.0mL/min;检测波长:272nm;柱温:室温;分离测定了元宝枫叶中游离和水解没食子酸的含量。用HPLC测定元宝枫中游离和水解没食子酸的含量。称取3g元宝枫叶粉末（过40目筛）置于锥形瓶中,加入乙醇溶液,水浴提取,在室温放冷备用。在505nm下测定吸光度,并根据标准曲线测定总黄酮含量。于340nm波长下测定NADPH每分钟吸光度的变化作为酶活性指标——△Ai,只加入萃取溶剂的测活结果?A0做为对照。计算快结合抑制程度I_f:I_f=（1-△A_i/△A₀）×100%,作为对FAS的抑制率。测定不同提取液量对FAS的抑制程度,使FAS酶活力被抑制50%时的提取物浓度（IC50）作为衡量快结合抑制能力的指标。比较元宝枫提取物抑制FAS活性的大小。结果游离没食子酸含量为0.045%;水解没食子酸含量为1.456%。黄酮提取率最高的工艺条件为:35℃温度下,乙醇浓度为70%,固液比为1:30,提取1小时,黄酮的提取率为8.43%。抑制FAS的最佳工艺条件为:55℃温度下,乙醇浓度为50%,固液比为1:30,提取2小时,IC50的值为0.011。结论游离没食子酸含量较少,水解没食子酸含量大。元宝枫叶提取物中黄酮类物质的含量与对FAS抑制效果之间不是正相关,表明只有一部分黄酮类成分对FAS有抑制作用。而元宝枫叶中含有大量的水解没食子酸,抑制FAS元宝枫活性成分可能与没食子酸和黄酮类成分的结合形式有关。更多还原

【Abstract】 OBJECTIVE: To detect free and hydrolysable gallic acid of Acer Truncatum Bunge by HPLC. To select the optimum conditions for extraction of flavonoids from leaves of Acer Truncatum Bunge and compare the inhibitory effect of the extracts against FAS. METHOD A method for determining gallic acid in leaves of Acer Truncatum Bunge by high performance liquid chromatography is described. The operating conditions were Diamonsil C18 column (5 μm, 4.6×250 mm) at room temperature, methanol ~ 0.025 mol/L phosphoric acid solution (15:85) as mobile phase at a flow of 1.0 mL/min and UV detection at 273 nm. The contents of flavonoids and the inhibitory effect against FAS of the extracts from leaves of Acer Truncatum Bunge were investigated. RESULTS The contents of free and hydrolysable gallic acid were 0.045% and 1.456%, respectively. The relative standard deviations of free and hydrolysable gallic acid were 1.06% and 2.43%, respectively. The contents of flavonoids and the inhibitory effect against FAS were not positively relative. CONCLUSION The contents of free and hydrolysable gallic acid of Acer Truncatum Bunge in different dates are different. Parts of flavonoids were effective to inhibit FAS. The inhibitory effect of the extracts against FAS maybe is relative to the combining form of gallic acid and flavonoids.更多还原