肉豆蔻酰矢车菊素-3-O-葡萄糖苷在混合溶剂体系中的酶法合成  

Enzymatic Synthesis of Myristoyl Cyanidin-3-O-Glucoside in a Mixed Solvent System

作　　者：张萍玲 赵振刚[1] ZHANG Ping-ling;ZHAO Zhen-gang(School of Food Science and Engineering,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]华南理工大学食品科学与工程学院,广东广州510640

出　　处：《现代食品科技》2021年第2期120-128,共9页Modern Food Science and Technology

基　　金：广东省水资源科学技术创新计划(201624);111项目(B17018);北京市食品营养与人类健康高级创新中心(20182004)。

摘　　要：为了提高矢车菊素-3-O-葡萄糖苷(C3G,Cyanidin-3-O-glucoside)的稳定性及亲脂性,本研究用固定化脂肪酶Lipozyme 435催化肉豆蔻酸甲酯对C3G进行酰基化修饰。首先分别在单一有机溶剂和混合有机溶剂中进行酰基化反应,然后通过半制备液相色谱对C3G酰基化衍生物进行分离纯化,并通过液质联用和核磁共振技术对其进行结构鉴定,最后在20%吡啶-叔戊醇溶剂中通过单因素实验和正交实验获得肉豆蔻酰C3G的最优合成条件。结果表明:在叔戊醇中分别添加20%(V/V)的吡啶、石油醚、正己烷、异辛烷后,C3G在混合有机溶剂体系中的酰基化反应转化率相比于单一有机溶剂体系显著提高(p<0.05)。20%吡啶-叔戊醇作为最佳反应介质使酰基化转化率由10.13%提高到15.62%。酰基化位点很有可能发生于C3G的6″-OH上,获得产物矢车菊素-3-(6″-肉豆蔻酰)-葡萄糖苷。肉豆蔻酰C3G的最优合成条件为:温度60℃、反应时间22 h、C3G与肉豆蔻酸甲酯摩尔比1:250、酶的添加浓度20 mg/mL,最终获得33.25%的转化率。本研究为进一步研究花色苷的稳定性及生物活性,拓展花色苷在脂溶性基质中的应用提供有益参考。In order to improve the stability and lipophilicity of cyanidin-3-O-glucoside(C3 G),immobilized lipase Lipozyme 435 was used in this study to catalyze the acylation of C3 G by methyl myristate.The acylation in a single organic solvent and a mixed organic solvent was investigated.Then,the acylated derivative of C3 G was separated and purified by semi-preparative liquid chromatography,and its structure was characterized by HPLC-MS/MS and NMR techniques.The optimal synthesis conditions of myristoyl C3 G were obtained in 20%pyridine-tert-amyl alcohol by single factor experiments and orthogonal experiments.The results showed that the conversion rate in a mixed solvent system(tert-amyl alcohol plus 20%V/V of pyridine petroleum ether,n-hexane or isooctane)was significantly improved(p<0.05)compared to that in a single organic solvent.The 20%pyridine-tert-amyl alcohol combination was the best reaction medium and allowed the increase of the conversion rate from 10.13%to 15.62%.The acylation most likely occurred on the 6″-OH of the glucose residue of C3 G to yield cyanidin-3-(6″-myristoyl)-glucoside.The highest conversion rate for myristoyl C3 G was achieved(33.25%)under the optimal synthesis conditions:60℃;reaction time,22 h;molar ratio of C3 G to methyl myristate,1:250;enzyme concentration 20 mg/mL.This study provides a useful reference for further research on the stability and biological activity of anthocyanins,and to expands the application of anthocyanins in lipophilic matrices.

关 键 词：矢车菊素-3-O-葡萄糖苷 酰基化 混合溶剂 

分 类 号：TS264.4[轻工技术与工程—发酵工程]