Comparative analysis of the major constituents in three related polygonaceous medicinal plants using pressurized liquid extraction and HPLC-ESI/MS

Abstract

A high-performance liquid chromatography (HPLC) coupled with a diode array detector (DAD) and electrospray ionization mass spectrometry (ESI/MS) method was developed for the simultaneous analysis of fourteen characteristic components, including piceid, 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside, rhaponticoside, torachrysone-8-O-β-D-glucoside, emodin-1-O-β-D-glucoside, resveratrol, emodin-8-O-β-D-glucoside, chrysophanol-8-O-β-D-glucoside, physcion-8-O-β-D-glucoside, aloe-emodin, rhein, emodin, chrysophanol, and physcion, in roots of Rheum officinale Baill. (RO), Polygonum multiflorum Thunb. (PM) and Polygonum reynoutria Makino. (PR). Sample extraction was conducted on a Dionex pressurized liquid extraction (PLE) system, and the sample analysis was performed under the optimized HPLC-ESI/MS conditions. A comprehensive validation of the developed method was conducted, and the method presented a good sensitivity, repeatability and accuracy. The unique properties of the present method were validated by analyzing 15 related herb samples including 5 RO samples, 5 PM samples and 5 PR samples. Fourteen components were identified by online ESI/MS and by comparison with literature data and standard compounds, and eight of them were quantified by using a DAD simultaneously. The key characteristic components for the quality control of a single herb were found by comparing the chemical composition of these three herbs. The overall procedure is highly precise and accurate which is considered suitable for qualitative and quantitative analysis of a large number of samples.