DEVELOPMENT AND VALIDATION OF A SPECTROPHOTOMETRIC METHOD FOR THE QUANTITATIVE DE-TERMINATION OF ANTHOCYANINS IN SEA BUCKTHORN LEAVES

Expanding the raw material base is one of the directions of the current stage of development of pharmacognosy. Search for new promising sources of biologically active substances, incl. among the morphological groups of official raw materials that are not currently being harvested on an industrial scale, will contribute to the further development and implementation of new domestic medicinal herbal preparations. Sea buckthorn leaves are rich in various biologically active substances (tannins, amino acids and organic acids, carotenoids, B vitamins, ascorbic acid, flavonoids, etc.). According to the literature, leaves rarely contain anthocyanins, but this does not exclude the presence of leucoanthocyanins, which can color «sour» extracts with a cherry-red color during long-term extraction, consequences of transformation under such conditions of extraction of anthocyanin compounds themselves. Based on the above, the purpose of the study was to develop and validate a spectrophotometric method for the quantitative determination of leukoanthocyanins in sea buckthorn leaves. The object of the study is the dried leaves of sea buckthorn (Hippophae rhamnoides L.) (humidity no more than 10%) of various phenological phases of the life of a plant growing in the Voronezh region (I (early June) - fruit set phase, II (mid-July) - phase the beginning of fruit ripening, III (late August-early September) - phase of mass fruiting). It has been established that the content of leucoanthocyanins in raw materials ranges from 1.8 to 2.3% depending on the phenological phase of the plant’s life. The developed methodology was validated according to the following indicators: precision (at the repeatability stage), detection limit, quantitative detection limit, linearity, linearity range. According to the results obtained, the method is valid and suitable for assessing the quality of sea buckthorn leaves. Since early harvesting of leaves can affect the quality of pharmacopoeial raw materials (fruits), the recommended phase for harvesting is the phase of mass fruiting (late August-early September). The results obtained will be included in the draft pharmacopoeial articles for sea buckthorn leaves. The results obtained contribute to expanding the understanding of the composition of the polyphenolic complex of biologically active substances of this annually available renewable plant material.