HPLC-DAD及HPLC-MS研究干燥工艺对中药粗榧化学成分的影响

用高效液相色谱-二极管阵列检测器及高效液相色谱-质谱联用技术,发现常压及减压干燥能使粗榧提取物中两个主要的化合物(1号峰和2号峰)发生降解。减压干燥后两个化合物分别减少了20.2%和45.6%,常压干燥后,两个化合物均检测不到。与干燥前相比,减压干燥和常压干燥使3号峰面积分别增加了1.90倍和5.74倍。1~3号峰均具有特征性的黄酮化合物的两个紫外吸收带(240~280 nm和300~400 nm),被推测为黄酮化合物,质谱研究推测1~2号峰发生了苷键断裂生成3号峰。用AB-8大孔吸附树脂,葡聚糖凝胶LH-20,反相硅胶(ODS)柱色谱分离纯化得到1~3号峰的3个化合物,对其进行了红外和核磁测定,鉴定出芹菜素-5-O-α-L-吡喃鼠李糖基(1→4)-β-D-吡喃葡萄糖苷和芹菜素-5-O-α-L-吡喃鼠李糖基(1→4)-6″-O-乙酰基-β-D-吡喃葡萄糖苷两个黄酮苷,干燥过程使它们苷键断裂生成了苷元芹菜素(3号峰)。

Effect of Drying on the Chemical Constituents of Cephalotaxus Sinensis Extract by HPLC-DAD and HPLC-MS

Two major components(peaks 1,2)in the extract of Cephalotaxus sinensis(Rehd et Wile)Li broke up during drying,which was investigated by techniques of high-performance liquid chromatography with photodiode array detection(HPLC-DAD) and high-performance liquid chromatography-electrospray ionization tandem mass spectrometry(HPLC-MS).The two components decreased by 20.2%,45.6%,respectively,after drying in vacuo,and they were not observed after drying under atmospheric pressure.The area of peak 3 increased by 1.90-and 5.74-fold,respectively,after drying in vacuo and under atmospheric pressure.It is inferred that the three peaks are flavones having two characteristic UV absorbance bands(240~280 nm and 300~400 nm) of flavones,and peaks 1~2 produce peak 3 by bond cleavage during drying.The extract was subjected successively to column chromatography on AB-8 macroporous absorbent resin,Sephadex LH-20 and reversephase silica gel(ODS) to afford three compounds.They are identified as apigenin-5-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside](peak 1),apigenin-5-O-α-L-rhamnopyranosyl-(1→4)-6-O-β-D-acetylglucopyranoside](peak 2) and apigenin(peak 3) by IR and NMR analysis,and the two flavone glycosides(peaks 1,2) produce apigenin,the aglycone,after drying.