Extraction and chromatographic determination of phenolic compounds from medicinal herbs in the Lamiaceae and Hypericaceae families: A review

The review is devoted to the study of the peculiarities of extraction of phenolic compounds from medicinal herbs of the Hypericaceae and Lamiaceae families, their identification and determination. The phenolic compounds of these herbs are biologically active substances which include mainly phenolcarboxylic and cinnamic acids and their derivatives, flavonoids, among which are flavones, isoflavones, flavanols, flavanones, flavanones, flavans, flavans 3,4-diols, catechins, biflavonoids and proanthocyanidins. In addition to these compounds, polynuclear compounds like hypericin, pseudohypericin, prenylated phloroglucinols and their derivatives have also been studied. It has been shown that the Hypericaceae and Lamiaceae families, as the main sources of valuable biologically active compounds (BAC), have widely been used in pharmacology. A large numbers of data on the extraction, identification and determination of pharmacological substances have been reported in the literature which critically presented in this review. The main methods of extraction of various components from plant raw materials using different chemical and physical factors have been reviewed along with their advantages and disadvantages. The lack of unified methods for extracting BAC from medicinal herbs or medicinal raw materials (MRM), the use of various options for their extraction, makes it very difficult to carry out the procedure for identifying and determining the composition in plant objects. Also, there have been problems in identifying the majority of phytocomponents due to their variety and at the same time similarity in physicochemical properties and structures. Thus, in the present review, the results of literature reported investigations concerning the extraction of phenolic compounds (PC) from medicinal herbs of the Hypericaceae and Lamiaceae families have been critically summarized, and their identification and determination by chromatography methods with different detection techniques have also been reviewed. In addition, the approaches to the development of analytical schemes for the determination of BAC in the representatives of the Hypericaceae and Lamiaceae families have also been summarized