枸杞叶黄酮提取物的组成及初步结构表征

本文采用高温乙醇回流法得到一种枸杞叶黄酮提取物，经硝酸铝－亚硝酸钠比色法测定该提取物的总黄酮含量为 347.00 mg/g。采用紫外－可见光谱(UV－Vis)和傅里叶变换红外光谱(FT－IR)对其进行初步结构表征，发现枸杞叶黄酮提取物的 UV－Vis 谱图中含有 A－环苯甲酰和 B－环肉桂酰系统的特征吸收峰，其 FT－IR 谱图也显示有C = C、羟基、酚羟基、甲氧基以及甲基等多种特征官能团的振动吸收峰，具有黄酮类化合物的典型结构。通过高效液相色谱(HPLC)测定枸杞叶黄酮提取物中各黄酮类化合物的组成与含量，得出该提取物含有芦丁、绿原酸、槲皮素、咖啡酸、对香豆酸、山奈酚6 种黄酮类化合物，含量分别为100.74、42.83、23.59、2.94、0.31、0.08 mg/g，表明提取物是一种富含芦丁、绿原酸和槲皮素的天然黄酮类物质，在天然食品添加剂和功能食品原料等方面具有开发利用价值。 

Composition analysis and preliminary structural characterization of the flavonoids from Lycium barbarum leaves

A flavonoids extract was obtained from Lycium barbarum leaves by ethanol refluxing method in high temperature，and its total flavonoids content was 347.00 mg/g detected by aluminum nitrate－sodium nitrite colorimetric method.The preliminary structural characterization of the flavonoids extract were determined by UV － visible spectroscopy (UV － Vis) and Fourier transform infrared spectroscopy (FT－IR) .The results showed that the flavonoids extract in Lycium barbarum leaves contained A－benzoyl ring and B－cinnamoyl ring structures in UV－Vis spectra，and had main characteristics of flavonoids functional groupsincluding C = C group，a hydroxyl group，a phenolic hydroxyl group，methoxy and methyl groups in FT－IR spectra，which indicated that the extract from Lycium barbarum leaves had the typical structure of flavonoids.The composition of flavonoids in the extract was analyzed by high performance liquid chromatography (HPLC) .The result showed that rutin，chlorogenic acid，quercetin，caffeic acid，p－coumaric acid and campherol existed in the flavonoids extract.The contents of them were 100.74，42.83，23.59，2.94，0.31 and 0.08 mg/g respectively，indicating that the extract was a kind of natural flavonoids substances rich in rutin，chlorogenic acid and quercetin，and had the value of development and utilization in natural food additives and functional food materials.