乳酸菌源共轭亚麻酸的分离制备

Isolation and preparation of conjugated linolenic acid from lactic acid bacteria

乳酸菌发酵产生的共轭亚麻酸(CLNA)在慢性疾病中有重要的生理功能,CLNA由多种异构体组成,各种异构体的生理功能存在差异。建立了分离制备乳酸菌发酵液中游离态CLNA异构体的方法,成功获得了结构单一的CLNA异构体。结果表明:在现有条件下乳酸菌源CLNA单一异构体无法通过薄层色谱法分离;高效液相色谱法可实现乳酸菌源CLNA单一异构体的分离,最优分离制备条件为高效液相色谱柱Ultimate(5XB-C30,4. 6 mm×250 mm)、流动相甲醇-水-甲酸(体积比70∶30∶0. 01)、流速1 m L/min、检测紫外波长205 nm和233 nm。在最优分离制备条件下,保留时间和峰面积的相对标准偏差分别为0. 05%～0. 38%、1. 88%～4. 65%,制备得到的CLNA1纯度为97. 48%,CLNA2的纯度为100%,CLNA3的纯度为65. 30%。该方法重复性好,分离度高,适合分离乳酸菌发酵液中游离形式CLNA。

Conjugated linolenic acid( CLNA) produced by lactic acid bacteria fermentation has important physiological functions in chronic diseases. And it has various types of isomers,which play different physiological roles. A method of isolating and preparing free CLNA from lactic acid bacteria fermentation was established and the single CLNA isomer was obtained successfully. The results showed that the single CLNA isomer from lactic acid bacteria could not be separated by thin layer chromatography under the existing conditions,while high performance liquid chromatography could realize. The optimal conditions were obtained as follows: chromatographic column Ultimate( 5 XB-C30,4. 6 mm × 250 mm),mobile phase methanol-water-formic acid( volume ratio 70∶ 30∶ 0. 01),flow rate 1 mL/min,UV wavelengths205 nm and 233 nm. Under the optimal separation and preparation conditions,the relative standard deviations of retention time and peak area were 0. 05%-0. 38% and 1. 88%-4. 65%,and the purity of CLNA1,CLNA2 and CLNA3 were 97. 48%,100% and 65. 30%,respectively. The method had good repeatability and separation,and was suitable for the separation of free CLNA from lactic acid bacteria fermentation.