Chemical constituents of the Moringa oleifera LAM. leaves collected in Bac Ninh province

Study on the chemical constituents of methanol extract from leaves of Moringa oleifera Lam. (Moringaceae) has resulted in the isolation of four compounds: Vitexin, isoquercitrin, tricosanol and tetradecanoic acid. Their structures were determined by spectroscopic methods.
Nội dung trích xuất từ tài liệu:
Chemical constituents of the Moringa oleifera LAM. leaves collected in Bac Ninh provinceJOURNAL OF SCIENCE OF HNUE DOI: 10.18173/2354-1059.2016-0051Natural Sci. 2016, Vol. 61, No. 9, pp. 21-25This paper is available online at http://stdb.hnue.edu.vn CHEMICAL CONSTITUENTS OF THE Moringa oleifera LAM. LEAVES COLLECTED IN BAC NINH PROVINCE Nguyen Thi Tam, Do Thu Huong and Pham Huu Dien Faculty of Chemistry, Hanoi National University of Education Abstract. Study on the chemical constituents of methanol extract from leaves of Moringa oleifera Lam. (Moringaceae) has resulted in the isolation of four compounds: vitexin (1), isoquercitrin (2), tricosanol (3) and tetradecanoic acid (4). Their structures were determined by spectroscopic methods. Keywords: Moringa oleifera, leaves, vitexin, isoquercitrin.1. Introduction Moringa is the sole genus in the small flowering plant family Moringaceae, which contains13 species from tropical and subtropical climates. Vietnam has only one species of this genus,Moringa oleifera. It is a small or medium-sized, about 10 m-high tree native to India andcultivated all over the country these days [1]. Moringa oleifera is considered one of the world’smost useful trees: its roots are useful for the treatment of asthma, gout, lumbago, rheumatism,enlarged spleenor liver, meanwhile its leaves, and flowers are used as a nutritive vegetable [2-5].Chemical study revealed that all parts of the plant contained steroids, flavonoids, triacylglycerols,and monoterpenes [2-5]. Among them, several biological activities including anti-microbial, anti-hypertensive [5, 6], anti-tumor promoter [2, 3], and anti-inflammatory [7] activities have beenreported. This paper describes the isolation but structural elucidation of four compounds of leavesof Moringa oleifera Lam., which were collected in Bac Ninh Province of Vietnam.2. Content2.1. Materials and methods * Plant material Leaves of Moringa oleifera Lam. were collected in Bac Ninh Province in November, 2014and identified by Mr. Do Huu Thu, PhD. (Institute of Ecology, Natural Resources and Biology,VAST, Vietnam). Voucher specimens are currently deposited at Faculty of Chemistry, HanoiUniversity of Education (TA201411).Received October 10, 2016. Accepted November 25, 2016.Contact Pham Huu Dien, e-mail address: dienph@hnue.edu.vn 21 Nguyen Thi Tam, Do Thu Huong and Pham Huu Dien * General procedure TLC was carried out on pre-coated Si gel GF254 (Merck Co., Germany), and TLC spots wereviewed at 254,302 and 366 nm and visualized by spraying vanillin-10% H2SO4 solution. Columnchromatography was carried out on silica gel 60 (60-100 M, Merck). NMR (1H, 13C NMR,DEPT, HSQC and HMBC) spectra were recorded on a Bruker Avance 500MHz. The chemicalshift (δ) values were given in ppm with TMS at internal standard, coupling constant J - by Hz.Mass spectra, including high resolution MS were recorded on a HP 5989B mass spectrometer andFT-ICR-MS (Varian 910-MS TQFTMS-7 Tesla). * Extraction and Isolation Dried powder of Moringa oleifera leaves (3,000 g) was extracted with methanol. Themethanolic extract was condensed to give a residue (350 g) which was further partitioned into n-hexane, EtOAc, BuOH and water. The ethyl acetate crude extract (14.5 g) was subjected tocolumn chromatography over silica gel and eluted gradient with n-hexane - ethyl acetate from 4:1to 1:1, ethyl acetate - methanol from 10:1 to 0:10. Eight fractions were successively obtained.Fraction 3 (125 mg) was separated by column chromatography (SiO2; n-hexane - ethyl acetate) toafford 1 (32 mg); fraction 7 (120 mg) - to afford 2 (25 mg). The n-hexane crude extract (10.5 g)was subjected to column chromatography over silica gel and eluted gradient with n-hexane - ethylacetate from 10:1 to 1:1. Four fractions were obtained. Fraction 2 (185 mg) were precipitatedwhite powder, after its crystallization to afford 3 (26 mg). Fraction 3 (78 mg) was separated bycolumn chromatography (SiO2; n-hexane - ethyl acetate) to afford 4 (5 mg). Compound 1: light yellow needles; ESI-FTICR-MS: m/z [M+H]+ calcd for C21H21O10:433.11347; found 433.11014. 1H NMR (500 MHz, DMSO-d6):  13.2 (1H, s, OH-5), 8.02 (2H, d,J = 8.5 Hz, H-2’, H-6’), 6.89 (2H, d, J = 8.5 Hz, H-3’, H-5’), 6.77 (1H, s, H-3), 6.21 (1H, s, H-6),4.68 (1H, d, J = 9.5 Hz, H-1”), 3.84 (1H, t, J = 9.0 Hz, H-2”), 3.76 and 3.53 (2H, m, H-6”), 3.26(1H, m, H-5”), 3.35 (1H, m, H-3”), 3.34 (1H, m, H-4”). 13C NMR (125 MHz, DMSO-d6): 182.1(C-4), 163.9 (C-2), 162.5 (C-7), 161.1 (C-5), 160.1 (C-4’), 156.0 (C-9), 128.9 (C-2’, 6’), 121.6(C-1’), 115.8 (C-3’, 5’), 104.6 (C-8), 104.0 (C-10), 102.4 (C-3), 98.1 (C-6), 81.8 (C-5”), 78.7 (C-3”), 73.4 (C-1”), 70.8 (C-2”), 70.5 (C-4”), 61.3 (C-6”). Compound 2: light yellow needles; ESI-FTICR-MS: m/z [M+H]+ calcd for C21H21O12:465.10331; found 465.10172. 1H NMR (500 MHz, CD3OD):  7.73 (1H, d, J =1.5 Hz, H-2’), 7.59(1H, dd, J = 8.5 2.0 Hz, H-6’), 6.89 (1H, d, J =6.5 Hz, H-5’), 6.41 (1H, d, J =1.5 Hz, H-8), 6.22(1H, d, J = 1.5, H-6), 5.26 (1H, d, J = 7.5 Hz, H-1”), 3.73 and 3.60 (2H, m, H-6”), 3.51 (1H, t, J =7.0 Hz, H-2”), 3.45 (1H, t, J = 8.5 Hz, H-3”), 3.37 (1H, t, J = 8.5 Hz, H-4”), 3.25 (1H, m, H-5”).13 C NMR (125 MHz, CD3OD): 179.5 (C-4), 166.0 (C-7), 163.0 (C-5), 159.0 (C-2), 158.5 (C-9),149.8 (C-4’), 145.9 (C-3’), 135.6 (C-3), 123.2 (C-1’), 123.1 (C-6’), 117.6 (C-2’), 116.0 (C-5’),105.7 (C-10), 104.4 (C-1”), 99.9 (C-6), 94.7 (C-8), 78.4 (C-5”), 78.1 (C-3”), 75.7 (C-2”), 71.2 (C-4”), 62.6 (C-6”). Compound 3: LC-MS: m/z 341.2 [M+H]+. 1H NMR (500 MHz, CDCl3): H 3.64 (2H, dd, J= 10.5 6 ...