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Chemical constituents of the leaves of alnus nepalensis D. Don. (Betulaceae)

Taraxeryl acetate (1), physcion (2), 1-nonacosanol (3), β-sitosterol (4), quercetin (5), βsitosterol 3-O-β-D-glucopyranoside (6), and quercitrin (7) were isolated from the leaves of Alnus nepalensis D. Don. (Betulaceae). Their structures were determined by spectroscopic methods. | Journal of Chemistry, Vol. 46 (4), P. 521 - 525, 2008 CHEMICAL CONSTITUENTS OF THE LEAVES OF ALNUS NEPALENSIS D. DON. (BETULACEAE) Received 28 March 2008 TRUONG THI TO CHINH1,2, PHAN MINH GIANG1, PHAN TONG SON1 1 Laboratory of Chemistry of Natural Products, Faculty of Chemistry, College of Natural Science, Vietnam National University, Hanoi, Vietnam 2 Vietnam Institute of Industrial Chemistry, Hanoi, Vietnam Summary Taraxeryl acetate (1), physcion (2), 1-nonacosanol (3), β-sitosterol (4), quercetin (5), βsitosterol 3-O-β-D-glucopyranoside (6), and quercitrin (7) were isolated from the leaves of Alnus nepalensis D. Don. (Betulaceae). Their structures were determined by spectroscopic methods. Keywords: Alnus nepalensis; Betulaceae; flavonoid; anthraquinone; phytosterol; triterpenoid. I - INTRODUCTION Woody plants have been known to produce many biologically active metabolites. In addition to the studies on chemical constituents of herbal medicinal plants, our phytochemical program also targets woody plants as potential sources of useful natural compounds. Alnus nepalensis D. Don. (Betulaceae) (Vietnamese name: Tống quán sủi) is a woody plant that reaches up to 10 - 15 m in height. The bark of A. nepalensis is used to treat diarrhoea, bacillary dysentery, and inflammatory diseases [1]. The study on A. nepalensis should be of interest since the constituents of Alnus species have been demonstrated to possess antioxidant [2], anti-inflammatory [3 - 5], anticancer [6] and hepatoprotective effects [2, 7]. In this paper the isolation and structural elucidation of seven compounds, taraxeryl acetate (1), physcion (2), 1-nonacosanol (3), β-sitosterol (4), quercetin (5), β-sitosterol 3-O-β-D-glucopyranoside (6), and quercitrin (7) (Fig. 1) from the MeOH extract of the leaves of A. nepalensis D. Don. (Betulaceae) collected in mountainous areas of northern Vietnam were reported. II - EXPERIMENTAL General Procedure Electron-impact (EI) mass spectra (70 eV) were measured on a