HPLC-MS sheds light on Chinese medicine

Analysis of raw and processed Radix Polygoni Multiflori (RPM) using high performance liquid chromatography and mass spectrometry (HPLC-MS) has offered an insight into the ways in which processing the root can lead to changes in its chemical make-up.

Scientists from Hong Kong Baptist University examined five pairs of raw and processed RPM, named R-RPM and P-RPM accordingly.

They used HPLC-MS to look at the levels of different chemicals in the root tubers before and after processing.

Emodin and physcion levels in general were higher in the P-RPM; however, this was not universally the case.

Physcion-8-O-(6-O-malonyl)-glucoside and emodin-8-O-(6-O-malonyl)-glucoside both disappeared following processing.

Both substances are anthraquinones - compounds known to have laxative effects when consumed orally.

The researchers suggest that the demonstrated differences between R-RPM and P-RPM are indicative of a change in chemical content, which may explain the belief in Chinese medicinal culture that the different compounds have differing pharmacological effects when used in patients.