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Journal of Chemistry, Vol. 42 (1), P. 132, 2004 short communication TWO LONG CHAIN ALKYL ALCOHOLS FROM THE LEAVES OF aCROTON TONKINENSIS GAGNEP., EUPHORBIACEAE Received 18-9-2003 Phan Minh Giang, Phan Tong Son Faculty of Chemistry, College of Natural Science, Vietnam National University In continuation of our reports on the chemical constituents of Croton tonkinensis Gagnep. (Euphorbiaceae) [1] this paper deals with the isolation and structure elucidation of two long chain alkyl alcohols. Two compounds 1 and 2 were isolated by repeated silica gel column chromatography of the n-hexane soluble fraction obtained from the methanol extract of the dried leaves of C. tonkinensis by liquid - liquid fractionation [2]. The long aliphatic chains of both compounds 1 and 2 were characterized by the 1H and 13C NMR spectra: H 0.88 (3H, t, J = 6.6 Hz), C 14.1 (q) for the terminal methyl groups; H 1.25 (m) and 1.56 - 1.6 (m), C 22.7 - 32.8 (all t) for the chain methylene groups. In the 1H and 13C NMR spectra of compound 1 the signals for the second methyl group at H 1.19 (3H, d, J = 6.3 Hz), C 23.5 (q) and for the neighbouring carbinol methine at H 3.8 (1H, sextet, J = 6.3 Hz), C 68.2 (d) were indicative for a secondary alcohol. The molecular ion peak was not visible in the EIMS spectrum of 1, but the peak at m/z 406 ([M-H2O]+.) allowed us to calculate the molecular formula of 1 as C29H60O. Thus the structure of 1 was elucidated as n-nonacosan-2-ol. Differing from alcohol 1 which possesses a secondary structure, the primary structure of alcohol 2 was deduced from the NMR signals at H 3.6 (2H, t, J = 6.6 Hz), C 63.1 (t). Compound 2 was determined as ntriacontan-1-ol on the basis of the EIMS peak at m/z 420 ([M-H2O]+.), C30H62O. 132 n-Nonacosan-2-ol (1). White powder. EIMS (70 eV) m/z 406 ([M-H2O]+.); 1H-NMR (300 MHz, CDCl3): 0.88 (3H, t, J = 6.6 Hz, CH3-29), 1.19 (3H, d, J = 6.3 Hz, CH3-1), 1.25 (m) and 1.60 (m) (26 CH2), 3.8 (1H, sextet, J = 6.3 Hz, CH-2); 13 C-NMR (300 MHz, CDCl3): 14.1 (q, C-29), 23.5 (q, C-1), 22.7, 25.8, 29.4, 29.7, 31.9 (all t, 25 CH2), 39.4 (t, C-3), 68.2 (d, C-2). n-Triacontan-1-ol (2). White powder. EIMS (70 eV) m/z 420 ([M-H2O]+.); 1H-NMR (300 MHz, CDCl3): 0.88 (3H, t, J = 6.6 Hz, CH3-30), 1.25 (m) and 1.56 (m) (29 CH2), 3.6 (2H, t, J = 6.6 Hz, CH2-1); 13C-NMR (300 MHz, CDCl3): 14.1 (q, C-30), 22.7, 25.7, 29.4, 29.6, 31.9, 32.8 (all t, 28 CH2), 63.1 (t, C-1). Acknowledgements: This research was supported by the International Foundation for Science, Stockholm, Sweden, through a grant to Phan Minh Giang, and the National Basic Research Program in Natural Sciences. References 1. Phan Tong Son, Van Ngoc Huong, Phan Minh Giang, C. Taylor Walter. Vietnam J. Chem., Vol. 37, No. 1-2 (1999). 2. Phan Tong Son, Phan Minh Giang, C. Taylor Walter. Austr. J. Chem., Vol. 53, P. 1003 - 1005 (2000). 3. Phan Minh Giang, Jung Joon Lee, Phan Tong Son. Vietnam J. Chem., Vol. 41, No. 1 (2003).