Лекции Reviews, Lectures
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| 3.3. Leaves with fl owers
A method for determining the authenticity of leaves with hawthorn fl owers was developed by thin layer chro- matography in a mobile phase: ethyl acetate – acetic acid – water (5: 1: 1) in the presence of witness solutions of: rutin, vitexin, chlorogenic acid, hyperoside [44]. In ad- dition, methods for qualitative and quantitative determi- nation of vitexin, rutin, hyperoside and quercetin in raw leaves with hawthorn fl owers was proposed by high per- formance liquid chromatography (HPLC) with spectro- photometric detection after preliminary extraction with 70% ethanol [45]. Foreign scientists have also developed a procedure for quantifi cation of procyanidins in leaves with haw- 115 Pharmacy & Pharmacology V. 6 N 2, 2018 DOI:10.19163/2307-9266-2018-6-2-104-120 atization of the research results in the fi eld of chemical standardization of hawthorn raw materials in Pharma- copoeias of various countries showed that the methods used to analyze the raw materials of the species of the genus Hawthorn (Crataegus L.), included into domes- tic and foreign Pharmacopoeias, various methodical and methodological approaches to standardization of fruits, fl owers and leaves are used. In addition, it was found out that raw materials of the same naming unit are analyzed by a variety of tech- niques. In our opinion, the use of various extractants in the methods is not always justifi ed from the point of view of the physico-chemical and spectral characteristics of the substances being analyzed. We have also shown that in the methods of qualitative and quantitative analysis of active substances (fl avonoids, procyanidins), the orienta- tion to diagnostically signifi cant standard substances is not always conducted. In this regard, a deeper study of the chemical composition of the hawthorn raw materials is necessary in order to identify signifi cant substances diagnostically, to select optimal extractants and extraction conditions, which will make it possible to develop scientifi cally validated approaches to standardization and to unify the methods of analysis of raw materials and preparations of hawthorn species. thorn fl owers by the method of ultra-effi cient liquid chro- matography with fl uorometric detection with preliminary preparation of water-acetone extraction from hawthorn raw materials [46].
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