Fingerprint analyses of AoE Chinese herbal based preparations and their herbal components with combination of chromatographic and chemometric techniques

Abstract

Traditional Chinese medicines (TCMs), including Chinese herbal based preparations are multicomponent chemical systems with components mostly unknown. Therefore this makes quality control of TCM a difficult task. However, chemical analyses of complex systems like TCMs can be greatly improved by chromatographic separation techniques coupled with chemometric methods that provide powerful data manipulation and information extraction. In this research project, these combined techniques were applied to investigate the developed Chinese herbal based preparations and their herbal components in the Area of Excellence (AoE) "Chinese Medicine Research and Further Development" project. The results obtained are found to be useful and reliable for authentication of the AoE herbal materials and for quality control of the preparations. Quality compliance and safety of the finished products of the five AoE Model Projects were evaluated with the use of a new quantitative indicator, similarity index (SI). Our results show that the stability of all the finished products against time is excellent and chemical fingerprints of all these products were set up. Authentication and standardization procedures of the two AoE formulations for treating child asthma were preformed by High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) and Gas Chromatography/Mass Spectrometry (GC/MS). Three identified components were 2,3-dihydro-3,5-dihydroxy-6-methyl-4-pyrone (DDMP), butyl hydroxy toluene (BHT), and cordycepin and they were reported to have pharmacological activities in the literature. Moreover, 29 water soluble components were identified in the formulation and they may serve as potential chemical or biological markers for future study. Discovery of new chemical marker of a herb can enhance quality control in confirming its presence in a formulation. One chemical marker of Baibu, a component herb in a child asthma formulation, was discovered with the use of the chromatographic and the recently developed spectral analysis technique. This demonstrated that the new spectral analysis technique provides much more spectral information than the conventional ones. Compositional variation of a component herb of Women's Aliment formulation, Radix Angelicae Sinensis (Danggui), was studied in detail on classification of its three different parts that were reported having different therapeutic effects in the Compendium of Materia Medica. This study provides new information to these parts in future biological screening studies. On the other hand, a simple, rapid, and non-destructive technique, Near Infrared Diffuse Reflectance Spectroscopy (NIRRS) was applied to quantitative analysis of Z-ligustilide, the major active ingredient of Danggui with results comparable to those of HPLC-DAD. Potential use of NIRRS as an effective alternative analytical method to conventional quantitative analysis of Danggui were successfully demonstrated.