槲皮素苯甲酸酯的合成与表征

以槲皮素为原料、浓硫酸作催化剂,85℃与苯甲酰氯反应,TLC板监测反应完毕,过滤、氯仿/甲醇重结晶合成标题化合物。UV表征显示,槲皮素的两个特征吸收峰均发生蓝移,这是形成新化合物共轭体系引起的。IR中ν—OH峰明显减弱,说明槲皮素的5个羟基中有的羟基发生了反应;νCO位于1 745.32 cm-1,酯羰基峰明显增强;νC—O位于1 259.66cm-1,峰变宽增强。1HNMR中3-OH、3'-OH、4'-OH上面的氢消失,说明与苯甲酰氯发生了酯化反应;同时,在δ6.7~8.4处有苯甲酰基的多重峰。MS中m/z 615.2为槲皮素三苯甲酸酯的分子离子峰。因此,槲皮素与苯甲酰氯反应可以得到标题化合物。

Synthesis and Characterization of Quercetin Benzoate Acid Esters

The quercetin benzoic acid esters were synthesized by filtration and recrystallization of chloroform/methanol after the reaction of quercetin,as raw material,with benzoyl chloride at 85 ℃ with the concentrated sulfuric acid as catalyst and the TLC plate as monitor.The UV shows that the two characteristic absorption peaks of quercetin both were blue-shifted,which was caused by the formation of a new conjugate system.The obviously decreased υ-OH peaks in IR indicate the reaction of some hydroxyl groups of the 5 hydroxyl groups of quercetin.The ester carbonyl peak was significantly enhanced as the υC=O at 1 745.32 cm-1.The peak width was enhanced as the υC-O at 1 259.66 cm-1.The disappearance of the hydrogen on 3-OH,3'-OH and 4'-OH in 1HNMR indicates that the esterification with benzoyl chloride occurred.At the same time,there were peaks of benzoyl groups at δ 6.7～ 8.4.The molecular ion peak of quercetin tribenzoate is m/z 615.2 (MS).Therefore,quercetin tribenzoate can be obtained by reaction of quercetin with benzoyl chloride.