Biological Fingerprinting Analysis For Probing The Interaction Of DNA And Extracts Of Traditional Chinese Medicines

Probing the interaction of the multiple components and the bio-macromolecule plays an important role in both screening of active compounds and understanding of the pharmacology of the traditional Chinese medicines (TCMs). The concept of the biological fingerprinting analysis of TCMs was proposed and a series of methods based on high performance liquid chromatography (HPLC) were developed for the qualitative and quantitative study of the interaction between the multiple active compounds in TCMs and the bio-macromolecules.A method of microdialysis sampling combined with HPLC was applied to the study of DNA-binding property for the extracts of TCMs. A number of alkaloids were found to bind to calf thymus DNA (ct-DNA) from the extracts of Coptis chinensis Franch, Phellodendron amurense Rupr. and Sophora flavescens Ait.. Three of them were identified as berberine, palmatine and jatrorrhizine and their association constants (K) to ct-DNA were determined. Competitive binding behaviors of them to ct-DNA were also investigated.A method by combination of centrifugal ultrafiltration (CUF) sampling with HPLC analysis was established to evaluate the DNA structure and sequence selectivity of the multiple compounds in TCMs. The developed method was applied to analyze the extracts of Coptis chinensis Franch and Rheum palmatum L.. DNA structural binding preference of the multiple active compounds in these two extracts was then evaluated simultaneously without purification.A novel stationary phase for HPLC with immobilization of DNA was prepared.Extract of Coptis chinensis Franch was separated and analyzed on this stationary phase with isocratic and gradient elution. This stationary phase was also applied to the solid phase extraction (SPE) and two-dimensional HPLC separation of TCM extracts.A racemate from Corydalis yanhusuo W.T. Wang, tetrahydropalmatine, was characterized on its enantioselective binding to DNA by the biological fingerprinting analysis. It was found that its (+)-enantiomer was preferential to binding on B-form duplex DNA including calf thymus DNA, AT and GC sequence oligo DNA, as well as triplex oligo DNA. In addition, the DNA structural preference of either enantiomer was also evaluated.