直观推导式演进特征投影法分辨枸杞类胡萝卜素的异构体

采用高效液相色谱-二极管阵列检测方法,初步分离了枸杞子中的类胡萝卜素。以乙腈-二氯甲烷(体积比为60∶40)为流动相,流速为1.0 mL/min,用C18柱从枸杞类胡萝卜素中分离出7个峰。但由于类胡萝卜素的结构多样性,尤其是顺反异构体的出现使得分离并不完全。利用所得三维数据提供的信息和化学计量学方法直观推导式演进特征投影法(HELP),对其中某些在二维色谱中被定性为单组分的峰进行解析,结果发现原来在二维色谱中被定性为单组分的峰大多是一些多组分峰。以其中第4个峰为例对其进行解析,得到了该类胡萝卜素的同分异构体色谱流出曲线及紫外光谱信息。该方法表明,化学计量学方法与现代分析手段有机结合,大大降低了此类复杂体系对色谱分离的要求,对同分异构体的分析具有一定的借鉴和指导意义。

Resolution of Carotenoid Isomers in Lycium barbarum L. by Heuristic Evolving Latent Projection

Lycium barbarum L., a kind of traditional Chinese herb, is found to have bioactivities such as anticancer, antioxidant, hypoglycemic and immunological activities. In both in vitro and in vivo studies, the carotenoids were found to be a class of the effective compounds. The carotenlysoids in Lycium barbarum L. were separated by high perforance liquid chromatography with diode array detection (HPLC-DAD). Seven peaks were obtained by HPLC on a C18 column with acetonitrile-methylene chloride (60:40, v/v) as mobile phase at a flow-rate of 1.0 mL/min. Most of the peaks that had been validated as single peaks in the 2-dimensional chromatography were found to be overlapping peaks. The overlapping chromatographic peaks were resolved by chemometric method--Heuristic Evolving Latent Projection (HELP) based on 3-dimensional data. As an example, the chromatogram and UV spectra of 4 isomers were obtained by resolving an overlapping peak. These results showed that the combination of chemometric methods and modern analytical instruments provides an effective method for the analysis of complex systems such as isomers.