Polyprenols from Vitis vinifera Leaves and Their Hepatoprotective Activity

Abstract

Polyprenols from leaves of Vitis vinifera L. (Vitaceae) growing in Surkhandarcya Oblast were studied. It was shown that V. vinifera was richer in polyprenols than cultivated varieties. A study of the biological activity of the total polyprenols identified their hepatoprotective activity.The grape Vitis vinifera L. (Vitaceae) is cultivated in the Caucasus, Ukraine, Moldova, Crimea, and Central Asia. The variety V. vinifera is subdivided into three principal ecological-geographical groups. The east-Asian group includes over 40 species of poorly studied grape varieties [1], in the leaves of which sugar, quercetin, inositol, tanning agents, carotene, betaine, tocopherol, ascorbic acid, and organic acids (tartaric, malic, and protocatechoic) and the macroscopic and trace elements K, Ca, Na, Mg, Fe, Al, Zr, Si, P, S, Cl, etc. were detected [2, 3]. The preparation Vivisan for treating varicose veins was developed based on the EtOH extract of cultivated V. vinifera leaves. Tincture of dry grape leaves is used for rinsing and treating several skin diseases. The cold tincture of the leaves is used to strengthen eyes and to treat rheumatism. The decoction of the leaves makes urine basic and gradually dissolves urate kidney stones. Powder of dried grape leaves is inhaled for nose bleeds. The EtOH extract of grape leaves possesses antioxidant activity [4].We studied previously polyprenols (PP) from leaves of the white grape variety Buvaki growing in Tashkent Oblast and developed the optimum extraction method [5]. Herein we present data on the constituent composition of total neutral substances (NS) from leaves of wild red grape and their biological activity.Raw material (200 g) was extracted with EtOH (96%). PP were isolated by condensing the EtOH extract to 1/3 the volume and treating it with weak NaOH solution to remove free acids. The precipitate was saponified by the literature method [6] to afford total NS [10.4 g, 5.2% of air-dried mass (ADM)]. The PP content in total NS was determined by HPLC. The standards were Rhus coriaria PP [7]. Table 1 presents the data.The remaining constituents of total NS were determined by GC/MS analysis without fractionation. According to the HPLC analysis, the PP content in total NS was 45.7% (2.35% of ADM). Other constituents of total NS (GC/MS analysis) included hydrocarbons, phytol, farnesol, geraniol, linalool, ethyl palmitate, etc. (Table 2).The selected conditions did not allow the constituents to be well separated. The main constituent of the total NS was phytol (Table 2), the content of which was 66.15%. Minor constituents were volatile terpenes and hydrocarbons, the contents of which were 2.87%. PP were isolated from the total NS by column chromatography. The yield of the PP fraction was 4.48 g (44.8% of total NS) with PP content 75.2%. IR, PMR, and 13 C NMR spectra were used for the identification. The spectral characteristics of the isolated PP agreed with those in the literature [5,8].PP exhibit various biological activities. The abilities to stimulate regenerative processes in ...