中药三七乙酰化前后化学组成的检测和比较研究

目的:研究三七提取液衍生化(本文中采用了乙酰化)和蒸发光散射检测器(evaporative 1ight-scattering detector,ELSD)在中药三七组分分析和鉴定中的应用.方法:采用乙腈-水梯度洗脱、紫外检测的方法,比较乙酰化前后的三七样品提取液的高效液相色谱(high performance liquid chromatography,HPLC)图谱差异;分别采用乙腈-水(体积比30:70)和乙腈-水(体积比85:15)作为流动相,比较用ELSD和紫外检测器时三七样品提取液的HPLC图谱差异.结果:在三七提取液乙酰化后,可以观察到在原样品色谱图中较早洗脱出的组分的变化,其中某些组分衍生物的保留时间大大延长.分别用ELSD检测和紫外检测可以得到不同的色谱图,用ELSD检测方法可以得到几种不同变化方式的峰群,从而提供了更多的三七提取液化学组成的信息.结论:三七提取液乙酰化后,其中一些亲水组分的极性大大降低,那些在反相色谱中较早流出、较难分离的组分经衍生化后出峰状况得到改善,ELSD还可以检测到有药理作用但因没有紫外吸收较难检测的糖类,这些都给中药三七的分析和鉴定提供了新的思路.

Comparative study of the composition of TCM Radix notoginseng extract samples before and after acetylation with UV and ELSD detection

To study the derivation,acetylation specifically,as well as the application of e-vaporative light-scattering detector(ELSD)detection of Panax notoginseng extract for a better under-standing of its components,as well as to study the authentication of this Traditional Chinese Medicine(TCM).Methods:Acetonitrile-water gradient elution of the samples was used for the analysis and theultraviolet(UV)detection used to observe the difference between the extract samples before and afteracetylation.Mobile phases containing 30% and 85% acetonitrile,respectively,were used to observe thedifferences between chromatograms of the samples obtained using UV and ELSD detection.Results:Byacetylating the extract before analysis,differentiation of the early-eluting components was observed,someof the derivatives were retained extremely strongly.Different eluting profiles were obtained from the ex-tract samples using UV and ELSD.Using the latter technique,different patterns of change in the reten-tion of peaks could be observed,uncovering more information relating to the composition of the extract.Conclusion:The decrease of polarities of a part of the hydrophilic components as a result of acetylation ofthe extract,and the differentiation of these early-eluting,difficult-to-separate compounds in the chromato-grams should be helpful for the characterization and authentication of the TCM.ELSD can be used to de-tect the carbohydrates,which are known to have pharmacological effects,and sensitize the detection ofglycosides.This is also helpful for the above-mentioned aspects.