Chemical assay of glycyrrhizin in medicinal plants by pressurized liquid extraction (PLE) with capillary zone electrophoresis (CZE)

Abstract

Chemical assay of glycyrrhizin in medicinal plants by pressurized liquid extraction (PLE) with capillary zone electrophoresis (CZE)Glycyrrhizin in Radix glycyrrhizae or liquorice was determined using a laboratory made dynamic pressurized liquid extraction (PLE) system coupled with capillary zone electrophoresis (CZE). The amount of glycyrrhizin was determined using CZE with an aqueous buffer of 10 mM of sodium tetraborate at pH 9.25 with UV detection at 254 nm. The effects of pH, buffer concentration, and the applied voltage on the electrophoretic separation were investigated. Temperature was found to be the important parameter in PLE as it was observed that the amount of thermally labile components such as glycyrrhizin extracted from medicinal plants decreased with increasing temperature from 100 to 1608C. The amount of glycyrrhizin extracted by PLE with methanol as solvent for glycyrrhizin in medicinal plants was found to be comparable or higher compared to multiple step ultrasonic extraction using a mixture of methanol/ water (70 : 30). The overall method precision was found to vary from 6.9 to 8.1% (RSD) for glycyrrhizin in medicinal plants. The specificity of the method was checked using standard addition experiments. Figure 1. Chemical structures of A) 18b-glycyrrhetinic acid and B) glycyrrhizin.

Extraction methods and chemical standardization of botanicals and herbal preparations

“…Application of PLE, using commercially available systems based on static extraction to medicinal plants, was reported [32,33]. Our laboratory have reported the used of a laboratory made dynamic PLE system for the extraction of aristolochic acids, berberine, strychnine, ginsenosides, glycyrrhizin, baicalein and others in medicinal plants and herbal preparations [34][35][36][37][38]. It was observed that the extraction efficiency of marker compounds in botanicals and herbal preparations by PLE was comparable or higher than Soxhlet extraction.…”

“…In our laboratory, analytical methods using CE, included the determination of aristolochic acids in R. aristolochiae, strychnine in Strychnos nux-vomica, berberine in Rhizoma coptidis (Huang-lian) and glycyrrhizin in R. glycyrrhizae (liquorice) [35,37,53]. CZE was found to be a method for the rapid separation and determination of four phenylpropanoid glycosides from T. chamaedrys [58].…”

Multi-component HPLC Fingerprinting of Radix Salviae Miltiorrhizae and Its LC-MS-MS Identification

“…In recent years, chromatographic fingerprinting has been shown to be an efficient method for evaluating herbal medicines since the chromatography has very powerful separation ability. 14,15) Multiple components in traditional Chinese medicines can be simultaneously separated by using HPLC, gas chromatography (GC), high performance thin layer chromatography (HPTLC) and capillary electrophoresis (CE). Indeed, the use of HPLC coupled with a diode array detector (DAD) for the fingerprinting of Radix Salviae Miltiorrhizae and its preparations has been reported.…”

Quality Control by Immunoaffinity Concentration Using Monoclonal Antibody

“…For example, various methods for separation and quantification of glycyrrhizin (GC), the main active constituent in licorice (Glycyrrhiza spp. ), have been used such as gas chromatography, high performance liquid chromatography (HPLC), and micellar trokinetic chromatography (Ong, 2002;Lay et al, 2004;Tan et al, 2002). Commercial purification of GC typically progressed through several steps, including crystallization, column chromatography, and liquid partitioning.…”