紫玉米苞叶花色苷的纯化鉴定及热稳定性分析
Study on purification and identification of anthocyanins from purple corn bract and its thermal characterization
-
摘要: 为明确紫玉米苞叶花色苷的组成及比较单体花色苷的热稳定性,实验采用大孔树脂、凝胶树脂分离纯化紫玉米苞叶花色苷提取物,得到三个不同花色苷组分,并采用液质联机的方法鉴定其结构;将制备的花色苷提取物及三个单体组分进行热重仪器分析,比较不同组分的热稳定性。结果表明紫玉米苞叶中共含有6种花色苷,通过分离纯化后能够得到三个组分,第一个组分为芍药-3-O-葡萄糖苷和天竺葵-3-O-葡萄糖苷的混合物,第二个组分为矢车菊-3-O-葡萄糖苷,第三个组分为矢车菊-3-(6’丙二酰-葡萄糖苷)。其中总花色苷提取物的热稳定性最强,矢车菊-3-(6’丙二酰-葡萄糖苷)次之,芍药-3-O-葡萄糖苷和天竺葵-3-O-葡萄糖苷的混合物与矢车菊-3-O-葡萄糖苷热稳定性相当,均较以上组分弱。Abstract: In order to clarify the anthocyanins composition and assess their thermal characterization in vitro, anthocyanins in the purple corn bract were purified by Amberlite XAD-7 and LH-20 and identified by HPLC-MS. The thermal characterization of anthocyanin was studied by thermogravimetry ( TG) analysis. The results showed that purple corn bract contained 6 kinds of anthocyanins.Three portions were obtained after purifying by LH-20.The first portion was mixture of pelargonidin-3-glucoside and peonidin-3-glucoside, which exhibited the least thermal stability as the second portion containing cyanidin-3-glucoside. The third portion was cyanidin-3- ( 6 ’- malonylglucoside) which exhibited less thermal stability.The total anthocyanin extract purified by Amberlite XAD-7 exhibited the strongest thermal stability.