Applications of HPLC/MS in the analysis of traditional Chinese medicines

Gan-Cao, or licorice, is a popular Chinese herbal medicine derived from the dried roots and rhizomes of Glycyrrhiza uralensis, G. glabra, and G. inflata. The main bioactive constituents of licorice are triterpene saponins and various types of flavonoids. The contents of these compounds may vary in different licorice batches and thus affect the therapeutic effects. In order to ensure its efficacy and safety, sensitive and accurate methods for the qualitative and quantitative analyses of saponins and flavonoids are of significance for the comprehensive quality control of licorice. This review describes the progress in chemical analysis of licorice and its preparations since 2000. Newly established methods are summarized, including spectroscopy, thin-layer chromatography, gas chromatography, high-performance liquid chromatography (HPLC), liquid chromatography/mass spectrometry (LC/MS), capillary electrophoresis, high-speed counter-current chromatography (HSCCC), electrochemistry, and immunoassay. The sensitivity, selectivity and powerful separation capability of HPLC and CE allows the simultaneous detection of multiple compounds in licorice. LC/MS provides characteristic fragmentations for the rapid structural identification of licorice saponins and flavonoids. The combination of HPLC and LC/MS is currently the most powerful technique for the quality control of licorice.

Metabolomics represent a global understanding of metabolite complement of integrated living systems and dynamic responses to the changes of both endogenous and exogenous factors and has many potential applications and advantages for the research of complex systems. As a systemic approach, metabolomics adopts a "top-down" strategy to reflect the function of organisms from the end products of the metabolic network and to understand metabolic changes of a complete system caused by interventions in a holistic context. This property agrees with the holistic thinking of Traditional Chinese Medicine (TCM), a complex medical science, suggesting that metabolomics has the potential to impact our understanding of the theory behind the evidence-based Chinese medicine. Consequently, the development of robust metabolomic platforms will greatly facilitate, for example, the understanding of the action mechanisms of TCM formulae and the analysis of Chinese herbal (CHM) and mineral medicine, acupuncture, and Chinese medicine syndromes. This review summarizes some of the applications of metabolomics in special TCM issues with an emphasis on metabolic biomarker discovery. © Georg Thieme Verlag KG Stuttgart · New York.

This review summarizes the recent advances in the chemical analysis of Danshen and its finished products, including the introduction of the identified bioactive components, analytical methods for quantitative determination of target analytes and fingerprinting authentication, quality criteria of Danshen crude herb and its preparations, as well as the pharmacokinetic and pharmacodynamic studies on the active components of Danshen and its finished products. Danshen contains mainly two types of constituents, the hydrophilic depsides and lipophilic diterpenoidal quinones and both of them are responsible for the pharmacological activities of Danshen. In order to monitor simultaneously both types of components which have different physicochemical properties, numerous analytical methods have been reported using various chromatographic and spectrophotometric technologies. In this review, 110 papers on analysis of Danshen are discussed, various analytical methods and their chromatographic conditions are briefly described and their advantages/disadvantages are compared. For obtaining a quick, accurate and applicable analytical approach for quality evaluation and establishing a harmonized criteria of Danshen and its finished products, the authors' suggestion and opinions are given, including the reasonable selection of marker compounds with high concentration and commercial availability, a simple sample preparation procedure with high recoveries of both the hydrophilic phenols and lipophilic tanshinones, and an optimized chromatographic condition with ideal resolutions of all the target components. The chemical degradation and transformation of the predominant constituent salvianolic acid B in Danshen during processing and manufacturing are also emphasized in order to assure the quality consistency of Danshen containing products.