Application of high-speed counter-current chromatography combined with macroporous resin for rapid enrichment and separation of three anthraquinone glycosides and one stilbene glycoside from Rheum tanguticum.

In this paper, an efficient method was successfully established by the combination of macroporous resin (MR) and high-speed counter-current chromatography (HSCCC) for rapid enrichment and separation of aloe-emodin 8-O-ß-D-glucoside, emodin 1-O-ß-D-glucoside, emodin 8-O-ß-D-glucoside and piceatannol 4'-O-ß-D-(6″-O-gallate)-glucoside. Six kinds of macroporous resins were investigated in the first step and X-5 macroporous resin was selected for the enrichment of the target compounds. The recoveries of the target compounds reached 89.0, 85.9, 82.3 and 84.9% respectively after 40% ethanol elution. In the second step, the target compounds were separated by HSCCC with a two-phase solvent system composed of chloroform/ethyl acetate/methanol/water (8:1:6:5, v/v). The established method will be helpful for further characterization and utilization of Rheum tanguticum. The results demonstrate that MR coupled with HSCCC is a powerful technique for separation of bioactive compounds from natural products.

[Determination of trace elements in Niuhuang Jiedu tablets by microwave digestion and ICP-AES].

Niuhuang Jiedu tablets were digested with HNO3-H2O2 system by microwave digestion. The fourteen trace elements of As, Ca, Mg, Al, Mn, Sr, Ba, Se, Ni, Cd, Cu, Zn, Mo and Pb in the solution were determined by ICP-AES. The ICP-AES result proved to be reliable by adding standard recovery experiment to the process. By comparison with the result of chemical experiment, thr present method was accurate, quickly-accessible, and convenient. It was used for Niuhuang Jiedu tablets with result satisfactory.