Isolation And Purification Of Chemical Constituents From Galla Chinensis

The system of Traditional Chinese Medicine(TCM) is built on the rich experience of herb users, which has been accumulated since the birth of Chinese cultures several thousands years ago. Although there is no systematic modern studies on the pharmacology of traditional Chinese medicine, efficiency of these herbs were confirmed. Great attentions have been paid to TCM in recent years, because as new drug resources the compounds in TCM have the characteristics of all natural (or natural compounds derivatives) and good disease coverage. With the introduction of modern technique to TCM, there comes the big chance for TCM development. Some complicated pharmacological issue of TCM has at least in part been unveiled. More and more chemical structures of active compounds and relative molecular targets in TCM have been identified. Systematic compounds isolation and chemical structure characterization are key integral parts in TCM modernization, which will not only provide molecular basis for TCM pharmacology but also helps to find more new drugs against certain targets.Galla chinensis is the Melaphis chinensis (Bell) Baker galls of certain plants such as Rhus chinensis Mill, Rhus potaninii Maxim, and Rhus punjabensis Stewart var. sinica (Diels) Rehd.et Wils. Traditionally, Galla chinensis is widely used in some common diseases including lung astringing, fever reducing, diarrhoea relieving, detoxification and wound healing. Due to its complicated chemical constituents, active compounds of Galla chinensis are not very clear. Some primary studies showed that tannin is effective compound in the herb; in-depth pharmacological study still needs to be carried out. Aim of the present paper is to systematically isolate chemical constituents of Galla chinensis by using high performance liquid chromatography (HPLC) and D101macroporous resin chromatography methods. Our results will provide molecular basis for further pharmacological investigation of Galla chinensis.Crude extracts of Galla chinensis was prepared by water boiling method. Crude extracts was concentrated in a vacuum dryer, and then applied to D101macroporous resin column. Five fractions were generated from the primary fractionation. The fractions were further fractionated; six compounds have been isolated so far. Chemical structures of6compounds (Methyl gallate, Ethyl gallate, Pentagalloyl-β-D-glucose) have been deciphered by mass spectrometry (MS),1H-nuclear magnetic resonance (NMR) and13C NMR methods. Purities of the compounds are shown to be100% (Methyl gallate),100% (Ethyl gallate),100%(Ellagic acid),99.1% (1,2,3,6-Tetra-O-galloyl-β-D-glucose),100% (Pentagalloyl-β-D-Gluc ose),100% (Gallic acid)as analysis by area normalization method.