Study On The Method Of Quality Assessment Of The Leaves Of Diospyros Kaki L.f.

Persimmon leaf is the fresh or dried leaves of Diospyros kaki L.f. (Ebenaceae). It has many pharmacological activities and is widely used as medical materials for several hundred years. Persimmon leaf is employed in the treatment of hypertension, heart disease, the internal haemorrhage induced by gastric ulcer, the functional bleeding of ulterus and so on. The chemical constituents are very complex including flavonoids, triterpenoids, coumarins, phenols, etc.The quality control and evaluation of persimmon leaf is mainly by orthodox pharmacognostic methods which have lower technical contents. It's an important task to establish a system for quality control and evaluation of persimmon leaf as the utilization is more and more population and can make it enter the world's market as medical material today.A review on the development of research about chemical constituents and pharmacological activities of the leaves of Diospyros kaki L. f. was presented in this paper. It can give us a detailed understanding about persimmon leaf as a medical material.Our research for quality control and evaluation of the leaves of Diospyros kaki L. f. mainly include three parts.Firstly, we determined the contents of flavonoids in persimmon leaves collected by high performance liquid chromatography. Flavonoids are important components and have many pharmacodynamic actions. Early research on its total contents is mainly by UV Spectrophotometry which has low degree of accuracy. Flavonoids in persimmon leaves mainly are glycoside of quercetin and kaempferol which can hydrolyze in acidic waters. So we applied acidic waters and methanol as extracting solvent and heated at 85℃ to extracting flavonoids. HPLC separation was performed at room temperature (25℃) and a flow rate of 0.8ml/min. The mobile phase is met(?)anol and 0.1% H₃PO₄ water(55 : 45, v/v). The wavelength is 360nm. We investigated 26 samples collected from Shandong province and other habitat and compared their differences influenced by habitats and collection time.Secondly, we studied the chromatographic fingerprints of persimmon leaves and its extract. We also compared the differences between medical materials and its extracts.Chromatographic fingerprint technique is a useful method in the identification of herbal samples or their products, and hence has been widely used for studying traditional Chinese medicines (TCM). It is an advanced technology for quality control and evaluation of Chinese herbal medicine and is generally approved internationally.Traditionally, only a few of markers or pharmacologically active constituents were employed to assess the quality and authenticity of the complex TCM. However, as we know, the therapeutic effects of TCM are based on the complex interaction of numerous ingredients in combination, which are totally different from that of chemical drugs. Thus, many kinds of chemical fingerprint analysis methods to control the quality of TCM have gradually come into being, such as TLC, GC, HPLC, and so on. Among these methods, high-performance liquid chromatographic fingerprint has played more and more important role and was therefore introduced by the WHO as a strategy for identification and quality control of TCM.Unfortunately, although many chemical and pharmacological studies on the leaves of Diospyros kaki L.f. were already reported systematically many years ago, no chromatographic fingerprints for the quality control of the leaves of Diospyros kaki L.f. have been reported until now.In our present research, we focused on developing a simple, accurate and valid chromatographic fingerprint method to control the quality of the leaves of Diospyros kaki L.f. by high-performance liquid chromatography method. By using the professional software named " Similarity Evaluation System for Chromatographic Fingerprint of TCM " published by NPC (Version 2004A), multi-sample batches of samples were examined to generate a mean global chromatogram as the representative standard fingerprint and the similarity of each chromatogram against the mean global chromatogram was also calculated. We also applied SPSS software for sample classifications by Hierarchical clustering analysis method. The chromatographic fingerprint method we established can be used for identifying persimmon leaves of different habitat.Thirdly, we studied seven characteristic peaks in chromatographic fingerprints by HPLC/MS method and presumed their structures, by which we can get the new message of the black box about compositions of characteristic peaks in chromatographic fingerprints.