The C-glycoside embinin and its mono- and diacetate derivatives have immunotropic and cardiotonic activity, which makes the search for plants that contain them interesting. Embinin and its acetate derivatives were previously isolated only from some plants of the genus Iris, the habitat and growing conditions of which are very different from those of the genus Rubus. As a result of the study, the structure of seven C-glycosides, embinin derivatives, isolated from the leaves of Rubus chamaemorus L. (Rosaceae) was established. Using HR-ESI-MS, HPLC-MS, as well as one- and two-dimensional NMR spectroscopy, the structure of three substances isolated in individual form was established: embinin (1) and its diacetyl derivatives – 2''',3'''-diacetylembinin (5) and 3''',4'''-diacetylembinin (7). The method of stepwise hydrolysis of C-glycoside acetate residues proposed in this study, followed by HPLC analysis of the resulting hydrolysis products, made it possible to establish the structure of minor flavone C-glycosides contained in the leaves of Rubus chamaemorus L.: 2'''-acetylembinin (2), 3'''-acetylembinin (3), 4'''-acetylembinin (4) and 2''',4'''-diacetylembinin (6). All these compounds were found in the leaves of Rubus chamaemorus L. for the first time. The C-glycosides - embinin and its acetate derivatives are rare metabolites of higher plants, the presence of which is determined by the peculiarity of their physiology, and the biological activity determines the prospects for medical use.

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The aim of the study is to review the literature data on the chemical constituents of arial and underground parts of Geum rivale L. (Rosaceae) and the pharmacological activity of its extracts and individual compounds.Materials and methods. The study was carried out using Internet resources (Google Scholar, PubMed) and library databases (e-Library, Scopus, Web of Science). The main research methods were a review and analysis of the literature data on the topic for the period from 1958 up to the present.Results. For the period from 1958 up to the present more than 80 components in the arial and underground parts of G. rivale have been identified.  Among them there were components of the essential oil, phenolic acids and coumarins, aglycones of flavonoids, including luteolin, apigenin, quercetin and kaempferol, as well as a number of their glycosides and glucuronides, ellagitannins (hemin A, B, C, D, pedunculagin, stachiurin/casuarinin, tellimagrandin I). Some aspects of the pharmacological activity of total extracts and individual secondary metabolites of G. rivale have been studied, anti-inflammatory, antioxidant, antimicrobial, antiviral activities have been experimentally confirmed.Conclusion. The analysis of the literature data showed that a further study of the composition of metabolites of G. rivale and their pharmacological activity is an urgent task, the solution of which will expand the range of use of this plant in medical practice and consider G. rivale as a promising source of pharmaceutical substances for the creation of new drugs and biologically active additives.

В результате фитохимического исследования листьев морошки были выделены и установлены структуры одного нового (1) и четырех известных природных соединений (2 – 5). Соединение 1 – 4-О-α-L-арабинофуранозилэллаговая кислота и соединение 2 — (-)-эпикатехин относятся к классу таннинов. Соединения 3 – 5 представляют собой глюк- уроновые гликозиды флавоноидов — кверцетин-3-O-β-D-глюкуронид (3), кверцетин-3-O-β-D-2″-галлоилглюкуронид (4) и кемпферол-3-O-β-D-глюкуронид (5). Соединения 4 и 5 были идентифицированы и выделены из сырья Rubus chamaemorus L. впервые. Прогноз спектров биологической активности для выделенных соединений 1 – 5 с применением программы PASS позволил определить наиболее перспективные направления экспериментальных исследований их биологической активности.