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

To study the derivation, acetylation specifically, as well as the application of evaporative light-scattering detector (ELSD) detection of Panax notoginseng extract for a better understanding of its components, as well as to study the authentication of this Traditional Chinese Medicine (TCM).

Acetonitrile-water gradient elution of the samples was used for the analysis and the ultraviolet (UV) detection used to observe the difference between the extract samples before and after acetylation. Mobile phases containing 30% and 85% acetonitrile, respectively, were used to observe the differences between chromatograms of the samples obtained using UV and ELSD detection.

By acetylating the extract before analysis, differentiation of the early-eluting components was observed, some of the derivatives were retained extremely strongly. Different eluting profiles were obtained from the extract samples using UV and ELSD. Using the latter technique, different patterns of change in the retention of peaks could be observed, uncovering more information relating to the composition of the extract.

The decrease of polarities of a part of the hydrophilic components as a result of acetylation of the extract and the differentiation of these early-eluting, difficult-to-separate compounds in the chromatograms should be helpful for the characterization and authentication of the TCM. ELSD can be used to detect the carbohydrates, which are known to have pharmacological effects, and sensitize the detection of glycosides. This is also helpful for the above-mentioned aspects.