Biologically Active Compounds from Climacoptera obtusifolia

Abstract

Arid soils cover 34% of Kazakhstan. A multitude of halophytes grow on them. The chemistry of halophytes is of significant scientific and practical interest. Mainly salt-accumulating plants of the family Chenopodiaceae, which is represented in Kazakhstan by 47 genera and 218 species [1][2][3], exhibit halophilicity. These include plants of the genus Climacoptera, of which 14 species grow in Kazakhstan [4][5][6][7].Herein we communicate results for the chemical composition of C. obtusifolia collected during flowering in Almaty Region. An analysis of the constituents detected flavonoids (1.4%), saponins (2.3%), amino acids (2.7%), phenolic acids (1.8%), carbohydrates (2.5%), and coumarins (0.1%).Biologically active compounds from this plant were studied by extracting ground raw material with EtOH (70%) in a raw material-extractant ratio of 1:6-8 for 3 d at room temperature. The aqueous EtOH extract was concentrated. The concentrate was worked up successively with CHCl 3 , EtOAc, and n-BuOH with subsequent condensing of each fraction. Column chromatography over silica gel of the CHCl 3 fraction isolated 1-4 upon elution by CHCl 3 -hexane (9:1 and 8:2). Biologically active compounds were isolated from the n-BuOH extract using absorption-distributive chromatography over a nanosorbent produced by carbonization of plant raw material (rice husks) at the Institute of Combustion Problems, Al-Farabi Kazakh Nat. Univ.[7]. The eluents were H 2 O and aqueous EtOH in various ratios. Thus, compound 5 was isolated pure from the n-BuOH fraction.The isolated compounds were identified based on physicochemical data and comparisons with the literature as stigmasterol (1), C 29 H 28 O, FAB-MS m/z 412 [7] and dehydrodiconiferylaldehyde (2), C 20 H 21 O 6 , EI-MS m/z [M] + 356, white amorphous compound, [D] D 25 +20.0° (c 0.1, MeOH), mp 205°C (dec.), R f 0.5 (CHCl 3 -MeOH, 9.3:0.7). The IR spectrum of 2 exhibited absorption bands for CHO stretching vibrations (1670 cm -1 ) and skeletal benzene ring vibrations (1608, 1505). 1 Í NMR spectrum (300 MHz, CDCl 3 , G, ppm, J/Hz): 6.90 (s, H-2), 6.90 (s, H-5), 6.90 (s, H-6), 5.65 (d, J = 7.9, H-7), 3.70 (m, H-8), 3.96 (s, H-9), 7.05 (d, J = 1.3, H-2c), 7.13 (d, J = 1.3, H-6c), 7.40 (d, J = 17.5, H-7c), 6.61 (dd, J = 17.5, 8.5, H-8c), 9.65 (d, J = 8.5, H-9c), 3.88 (s, ÎMe), 3.94 (s, ÎMe), 5.70 (s, 4-ÎÍ), 9.65 (d, J = 8.5, 4-ÑÍÎ) [8]. 3-[2-(4-Hydroxy-3-methoxyphenyl)-3-hydroxymethyl-7-methoxy-2,3-dihydro-1-benzofuran-5-yl]propan-1-ol(3). C 20 H 25 O 6 , [M] + 360, white amorphous compound, [D] D 25 +5.5° (c 0.18, MeOH), mp 209°C (dec.), R f 0.5 (CHCl 3 -MeOH, 9.3:0.7). 1 Í NMR spectrum (300 MHz, CDCl 3 , G, ppm, J/Hz): 6.93 (d, J = 1.83, H-2), 6.86 (d, J = 8.09, H-5), 6.90 (dd, J = 8.09, 1.83, H-6), 5.54 (d, J = 7.48, H-7), 3.59 (m, H-8), 3.94 (dd, J = 10.91, 4.42, H-9a), 3.88 (dd, J = 10.91, 6.02, H-9b), 6.67 (s, H-2c), 6.65 (s, H-6c), 2.66 (t, H-7c), 1.87 (m, H-8c), 3.68 (t, J = 6.41, H-9c), 3.88 (s, ÎMe), 3.94 (s, ÎMe), 5.70 (s, 4-ÎÍ), 3.87 (s, 9-ÎÍ) >9@. 5,4c-Dihydroxy-6,7,3c-trimethoxyflavone ...