摘要
Two major isoflavone glycosides [calycosin 7-O-β-D-glucopyranoside （1） and ononin （2）] and their aglycones [calycosin （3） and formononetin （4）] were simultaneously quantified with HPLC/DAD method. Two unknown compounds were identified as calycosin 7-O-β-D-glucopyranoside-6＇＂-O-malonate （U1） and formononetin 7-O-β-D-glucopymnoside-6＇＂-O-malonate （U2）, respectively, with LC/MS^n. Raw Radix astragli were shown to have higher contents of isoflavone glycosides （1, 2）, but lower contents of aglycones （3, 4） than the processed herbal materials. After being moistened with water and stored up for 24 h at 35 ℃, the glycosides and their m_alonates were almost completely transformed to their corresponding aglycones. The different contents of the isoflavone glycosides and their aglycones in raw and processed Radix astragali materials might be due to enzymolysis of the glycosides during processing.
采用高效液相色谱-二极管阵列检测器(HPLC/DAD)方法测定黄芪药材和饮片中主要异黄酮苷及其苷元的含量,并采用高效液相质谱联用技术(LC/MS^n)鉴定主要未知色谱峰的结构。测定了黄芪药材及饮片中2个主要异黄酮苷:毛蕊异黄酮苷(1),芒柄花苷(2)及其相应苷元毛蕊异黄酮(3),芒柄花素(4)的含量,并鉴定了两个主要未知色谱峰的结构分别为毛蕊异黄酮苷6′″-O-丙二酸酯(U1)和芒柄花苷6′″-O-丙二酸酯(U2)。结果表明黄芪药材中异黄酮苷类成分的含量高于饮片,而苷元含量则低于饮片。另外,将黄芪药材粉末用水润湿后在35℃放置24小时,其中的异黄酮苷及其丙二酸酯类成分几乎全部转变成了苷元。黄芪中异黄酮苷类成分在一定条件下可转化为苷元,异黄酮苷和苷元在黄芪药材与饮片中含量的不同可能与饮片制备过程中苷类成分的酶解有关。
基金
National Natural Science Foundation of China(Grant No.20432030 and 20742005).
