Study on the chemical constituents in roots of Smilax glabra Roxb. cultivated in Thai Nguyen province

Abstract. From the ethanol extract of the Smilax glabra growing in Thai Nguyen province, five compounds such as stigmasta-5,22-diene-3β-ol (1), 3β-sitosterol-glucopyranoside (2), 4’,5,7-trihydroxyflavanone-3-O-α-Lrhamnopyranoside (engeletin) (3), 3’,5,5’,7-tetrahydroxyflavanone-3-O-α-Lrhamnopyranoside (smitilbin) (4), and 3’,4’,5,7-tetrahydroxyflavanone-3-O- α-L-rhamnopyranoside (astilbin) (5), were isolated. Their chemical structures were elucidated by IR, ESI-MS, 1D and 2D NMR experiments.

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JOURNAL OF SCIENCE OF HNUE Natural Sci., 2010, Vol. 55, No. 6, pp. 62-70 STUDY ON THE CHEMICAL CONSTITUENTS IN ROOTS OF Smilax glabra Roxb. CULTIVATED IN THAI NGUYEN PROVINCE Pham Thi Hong Minh, Nguyen Quyet Tien Institute of Chemistry, VAST Tran Thi Thanh Hang Thai Nguyen University of Education Pham Huu Dien(∗) Hanoi National University of Education (∗)E-mail: dienhp@gmail.com Abstract. From the ethanol extract of the Smilax glabra growing in Thai Nguyen province, five compounds such as stigmasta-5,22-diene-3β-ol (1), 3β-sitosterol-glucopyranoside (2), 4’,5,7-trihydroxyflavanone-3-O-α-L- rhamnopyranoside (engeletin) (3), 3’,5,5’,7-tetrahydroxyflavanone-3-O-α-L- rhamnopyranoside (smitilbin) (4), and 3’,4’,5,7-tetrahydroxyflavanone-3-O- α-L-rhamnopyranoside (astilbin) (5), were isolated. Their chemical struc- tures were elucidated by IR, ESI-MS, 1D and 2D NMR experiments. Keywords: Smilax glabra Roxb., isolation, steroits, engeletin, smitilbin, astilbin 1. Introduction Smilax glabra Roxb. plant belongs to the Smilacaceae family, wildly growing in several Provinces of Vietnam such as Lang Son, Quang Ninh (Tien Yen), Thai Nguyen (Dai Tu), Bac Giang, Vinh Phuc, Hai Duong, Ha Tay, Hoa Binh, Ninh Binh, Nghe An, Hue, Da Nang, Quang Nam, Kon Tum, Lam ong, Khanh Hoa, Ninh Thuan. In the world, Smilax glabra Roxb. plant is discovered in India, Myanma, China, Laos, Cambodia and Thailand. Smilax glabra Roxb. is medicinal plant of Vietnam to treat several diseases such as: piercing pain in the bones, detoxication, scabies, nephritis, cystitis, syphilis,... [1, 2]. Some compounds were found from Smilax glabra Roxb. roots such as dihydrokaempferol 3-O-α-L-rhamnopyranoside and astilbin [3]. 62 Study on the chemical constituents in roots of Smilax glabra Roxb... 2. Content 2.1. Materials and methods 2.1.1. General experimental procedures Melting points were determined by using an Electrothermal IA-9200 appara- tus. IR spectra was obtained by an IMPACT 410 type spectrometer in KBr disks. EI-MS was obtained by using a Hewlett Packard 5989 B MS spectrometer. ESI-MS was obtained by using a HP-1100 LS/MS Trap spectrometer. 1H-NMR (500 MHz) and 13C-NMR (125 MHz) spectra were recorded by a Bruker AM500 FT-NMR spec- trometer and TMS was used as internal standard. Column chromatography (CC) was performed on silica gel (Kieselgel 60, 70-230 mesh and 230-400 mesh, Merck). 2.1.2. Plant material The roots of Smilax glabra Roxb. were collected in Dai Tu, Thai Nguyen province, Vietnam, in January. 2007 and identified by Dr. Le Ngoc Cong, Education University of Thai Nguyen. A voucher specimen (No.PHM20070125) is deposited in the Hebarium of Dept. of Organic Chemistry, Hanoi National University of Education. 2.1.3. Extraction and Isolation The dried and powdered roots of Smilax glabra Roxb. (2.0 kg) were extracted three times with hot EtOH (at 600C). The combined extracts were then evaporated to give the ethanolic residue (118.6 g), which was suspended in water and extracted sequentially with n-hexane, ethyl acetate and methanol. Stigmasta-5,22-dien-3β-ol (23.0 mg), β-sitosterol-glucopyranoside (25.1 mg) were obtained from the n-hexane extract (8.3 g) by column chromatography. The ethyl acetate extract (37.3 g) was subjected to chromatography on a silica gel column, using chloroform-methanol (9:1) as eluent to yield six fractions (fractions A-F). Fraction C (1.6 g) and the combined fractions D-E (1.8 g) were separated on an YMC RP-8 column using MeOH-CHCl3 (7:3) as eluent. Three compounds were isolated as engeletin (20 mg) from fraction C; smitilbin (37.2 mg) and astilbin (29.1 mg) from the fraction E-D. * Stigmasta-5,22-dien-3β-ol (1): 1H-NMR (500 MHz, CDCl3); δ (ppm): 0.68 (3H, s, 18-Me); 1.01 (3H, s, 19- Me); doublet-doublet at δ 0.81 and 0.88 (2×3H, d, J 7.7 Hz, 26-Me and 27-Me); 0.83 (3H, t, 7.32 Hz, 29-Me); 0.92 (3H, d, J 10 Hz, 21-Me); 3,52 (1H, m, H-3α); 5.35 (1H, d, J 5 Hz, H-6). 13C-NMR (125 MHz, CDCl3); δ (ppm): 140.8 (s, C-5); 121.7 (d, C-6); 71.8 (d, C-3); 56.8 (d, C-14); 56.1 (d, C-17); 50.2 (d, C-9); 45.9 (d, C-24); 42.3 (s, C-13); 63 Pham Thi Hong Minh, Nguyen Quyet Tien, Tran Thi Thanh Hang and Pham Huu Dien 42.3 (t, C-4); 39.8 (t, C-12); 37.3 (t, C-1); 36.5 (s, C-10); 36.2 (d, C-20); 33.9 (d, C-8); 31.9 (t, C-7); 31.7 (t, C-2); 29.2 (d, C-25); 28.3 (t, C-16); 26.2 (t, C-23); 24.3 (t, C-15); 21.1 (t, C-11); 19.8 (q, C-26); 19.4 (q, C-19); 19.1 (q, C-27); 18.8 (q, C-21); 11.9 (q, C-29); 11.9 (q, C-18); 23.1 (t, C-28); 42.3 (t, C-4). * 3β-Sitosterol-glucopyranoside (2): FT-IR νmax (cm −1): 3390; 2934, 1644, 1464, 1461, 1373, 1073, 1026. ESI-MS: m/z (%): 396 [M - C6H12O6] + . 1H-NMR (500 MHz, DMSO-d6), δ (ppm): 0.70 (3H, s, 18-Me), 0.93 (3H, s, 19-Me), 0.94 (3H, s, Me). 13C-NMR (125 MHz, DMSO-d6), δ (ppm): 140.8 (s, C-5), 122.3 (d, C-6), 101.5 (d, C-1), 79.5 (d, C-3), 76.9 (d, C-5), 76.2 (d, C-3), 74.0 (d, C-2), 70.8 (d, C-4), 62.3 (t, C-6), 57.2 (d, C-14), 56.5 (d, C-17), 50.7 (d, C-9), 46.4 (d, C-24), 42.7 (s, C-13), 40.2 (t, C-12), 39.1 (t, C-4), 37.6 (t, C-1), 37.1 (s, C-10), 36.4 (d, C-20), 34.4 (t, C-22), 32.3 (d, C-8), 32.2 (t, C-7), 29.9 (t, C-16), 29.7 (t, C-25), 28.5 (t, C-2), 26.7 (t, C-23), 24.6 (t, C-15), 23.5 (t, C-28), 21.4 (t, C-11), 19.9 (q, C-19), 19.5 (q, C-21), 19.2 (q, C-26), 19.0 (q, C-27), 12.1 (q, C-29), 12.0 (q, C-18). * 4’,5,7-Trihydroxyflavanone-3-O-α-L-rhamnopyranoside (engeletin) (3): FT-IR νmax (cm −1): 3419, 2937, 1634, 1591, 1518, 1458, 1379, 1290, 1170, 1026, 977, 826. ESI-MS (m/z ): 433 [M - H]+ calc. for M = 434 (C21H22O10) 1H-NMR (500 MHz, MeOD), δ (ppm): 7.38 (2H, d, J 8,5 Hz, H-2 and H-6), 6.87 (2H, d, J 8.5 Hz, H-3 v H-5), 5.94 (1H, d, J 2.0 Hz, H-6), 5.92 (1H, d, J 2.0, H-8), 5.16 (1H, d, J 10.8 Hz, H-2), 4.63 (1H, d, J 10.8 Hz, H-3), 4.25 (1H, dd, J 3.6 and 10.8 Hz, H-3), 4.04 (1H, d, J 1.2 Hz, H-1), 3.67 (1H, dd, J 3.2 and 9.6 Hz, H-4), 3.53 (1H, dd, J 1.3 and 3.7 Hz, H-2), 1.20 (3H, d, J 6.2 Hz, H-6). 13C-NMR (125 MHz, DMSO-d6), δ (ppm): 196.02 (C-4), 168.60 (C-7), 165.49 (C-5), 164.11 (C-9), 159.42 (C-4), 130.03 (C-2), 130.03 (C-6), 128.60 (C-1), 116.46 (C-3), 116.46 (C-5), 102.52 (C-10), 102.22 (C-1), 97.43 (C-6), 96.29 (C-8), 83.84 (C-2), 78.70 (C-3), 73.78 (C-5), 72.17 (C-4), 71.76 (C-2), 70.54 (C-3), 17.83 (C-6). * 3’,5,5’,7-Tetrahydroxyflavanone-3-O-α-L-rhamnopyranoside (smi- tilbin) (4): FT-IR νmax (cm −1): 3493, 3443, 3314, 2950, 1619, 1581, 1465, 1366, 1153, 1042, 975. ESI-MS (m/z ): 451 [M + H]+ calc. for M = 450 (C21H22O11) 1H-NMR (500 MHz, DMSO-d6), δ (ppm): 11.74 (1H, s, 5-OH), 8.85 (2H, brs, 64 Study on the chemical constituents in roots of Smilax glabra Roxb... 3,5-OH ), 6.84 (1H, d, J 1.2 Hz, H-2), 6.74 (1H, s, H-4), 6.72 (1H, s, H-6), 5.94 (1H, d, J 2.0 Hz, H-8), 5.92 (1H, d, J 2.0 Hz, H-6), 5.54 (1H, d, J 2.5 Hz, H-2), 4.76 (2H, brs, H-1 ), 4.21 (1H, d, J 2.5 Hz, H-3), 3.47 (1H, brs, H-2), 3.19 (1H, dt, J 8.9 and 10.9 Hz, H-3), 3.05 (1H, t, J 6.1 and 9.1 Hz, H-4), 2.46 (1H, dd, J 6.4 v 9.4 Hz, H-5), 0.84 (3H, d, J 6.2 Hz, H-6). 13C-NMR (125 MHz, DMSO-d6), δ (ppm): 193.02 (C-4), 167.04 (C-7), 163.94 (C-5), 162.44 (C-9), 145.10 (C-3), 144.93 (C-5), 126.34 (C-1), 117.57 (C-4), 115.07 (C-6), 114.06 (C-2), 100.26 (C-10), 98.82 (C-1), 96.15 (C-6), 95.15 (C-8), 79.92 (C-2), 73.32 (C-3), 71.21 (C-4), 70.22 (C-3), 70.22 (C-2), 68.96 (C-5), 17.56 (C-6). * 3’,4’,5,7-Tetrahydroxyflavanone-3-O-α-L-rhamnopyranoside (astil- bin) (5): FT-IR νmax (cm −1): 3427, 3263, 2912, 1640, 1603, 1519, 1476, 1363, 1301, 1177, 1070, 977. ESI-MS (m/z ): 449 [M - H]+ calc. for M = 450 (C21H22O11). 1H-NMR (500 MHz, MeOD), δ (ppm): 6.97 (1H, d, J 1.8 Hz, H-2); 6.86 (1H, dd, J 8.2 v 1.8 Hz, H-6); 6.82 (1H, d, J 8.1 Hz, H5); 5.94 (1H, d, J 2.2 Hz, H-6); 5.92 (1H, d, J 2.0 Hz, H-8); 5.10 (1H, d, J 10.6 Hz, H-2); 4.58 (1H, d, J 10.7 Hz, H-3); 4.25 (1H, dd, J 3.6 and 6.3 Hz, H-1); 4.08 (1H, d J 1.3 Hz, H-1); 3.67 (1H, dd, J 3.3 and 10.6 Hz, H-3); 3.56 (1H, dd, J 3.1 and 1.6 Hz, H-2); 3.34 (1H, d, J 11.6 Hz, H-4); 1.20 (3H, d, J 6.3 Hz, H-6). 13C-NMR (125 MHz, MeOD), δ (ppm): 195.95 (C-4), 168.61 (C-7), 165.49 (C-5), 164.08 (C-9), 147.36 (C-4), 146.53 (C-3), 129.18 (C-1), 120.48 (C-6), 116.35 (C-2), 115.50 (C-5), 102.49 (C-10), 102.14 (C-1), 97.39 (C-6), 96.28 (C-8), 83.94 (C-2), 78.57 (C-3), 73.81 (C-4). 2.2. Results and discussion Repeated column chromatography of the n-hexane and ethyl acetate extracts of the dried and powdered roots of Smilax glabra on silica gel and YMC RP-8 yielded the five compounds as stigmasta-5,22-dien-3β-ol (1), 3β-sitosterol-glucopyranoside (2), engeletin (3), smitilbin (4) and astilbin (5). The chemical structures of com- pounds (1) and (2) obtained from n-hexane extract, were determinated by IR, ESI-MS, 1D and 2D NMR experiments and comparison of their spectral data with stigmasta-5,22-dien-3β-ol and 3β-sitosterol-glucopyranoside in reference [12]. Three remaining compounds engeletin (3), smitilbin (4) and astilbin (5) were isolated from ethyl acetate extract. The 1H-NMR and 13C-NMR spectra of (3), (4), (5) were typical for flavonoids possessing sugars [5-11] (see Table 1, 2, 3). 65 Pham Thi Hong Minh, Nguyen Quyet Tien, Tran Thi Thanh Hang and Pham Huu Dien R = H: Stigmasta-5,22-diene-3β-ol (1) R = Gluc: 3β-Sitosterol-glucopyranoside (2) R1 R2 R3 Engeletin (3) H OH H Smitilbin (4) OH H OH Astilbin (5) OH OH H Compound 3: yellow red crystals; mp. 178 - 1800C. The ESI-MS of (3) provided the molecular formula C21H22O11 (observed m/z: 451 [M + H] +; calcd for C21H22O11). According to 1H-NMR, 13C-NMR, DEPT of (3), this compound have total 21 carbon atoms, including 7 quartenary carbons at δC 102.52, 128.60, 159.42, 164.11, 165.48, 168.60 and 196.02; 14 methine groups (CH) at δC 70.54, 71.76, 72.17, 73.78, 78.70, 83.84, 96.29, 97.43, 102.22, 116.46, 116.46, 130.03, 130.03 and one methyl group (CH3) at δC 17.83. In 1H-NMR, olefin proton signals belong to aromatic at δH 5.94 (d, J 2.0 Hz, H-6), 5.92 (d, J 2.0 Hz, H-8), 7.38 (d, H-2), 7.36 (d, H-6), 6.87 (H-3), 6,85 (H-5) correlative with the carbon in succession at δC 97.43 (C-6), 96.29 (C-8), 130.03 (C- 2,6), 116.46 (C-3,5). In addition, the other proton signals at δH/C 5,16 (d, J 10.8 Hz, H-2)/83.84 (d, C-2), 4.63 (d, J 10.8 Hz, H-3)/78.70 (d, C-3) belong to cycle C. The proton doublet signal at δH/C 4.04 (d, J 1.2 Hz, H-1)/102.22 (C-1) belongs to sugar moiety. 1H-NMR, 13C-NMR, DEPT, HSQC and HMBC spectral data confirm that (3) is a flavonoid with rhamnopyranose sugar attach to C-3 of aglicon. 66 Study on the chemical constituents in roots of Smilax glabra Roxb... Compound 3 had determinated to be engeletin by 1H-NMR, 13C-NMR, DEPT, HSQC and HMBC spectral data and comparison with the spectral data of 4’,5,7- trihydroxyflavonone-3-O-α-L-rhamnopyranoside in references [6, 7, 9]. Table 1. 1H-NMR and 13C-NMR spectral data of (3) (in CD3OD) Compound 3 4’,5,7-trihydroxyflavonone No -3-O-α-L-rhamnopyranoside [6,7,9] δC δH ppm (J Hz) δC (DMSO) δH ppm (J Hz) (CD3OD) 2 83.84 5.16 (1H, d, J 10.8 Hz) 81.8 5.15 (1H, d, J 11.5 Hz) 3 78.70 4.63 (1H, d, J 10.8 Hz) 76.3 4.25 (1H, d, J 11.5 Hz) 4 196.02 195.4 5 165.48 163.7 6 97.43 5.94 (1H, d, J 2.0 Hz) 96.4 5.9 (1H, d, J 2.4 Hz) 7 168.60 167.4 8 96.29 5.92 (1H, d, J 2.0 Hz) 95.4 5.97 (1H, d, J 2.4 Hz) 9 164.11 162.5 10 102.52 101.3 1 128.60 126.8 2 130.03 7.37 (2H, d, J 8.5 Hz) 129.4 7.35 (2H, d, J 9.0 Hz) 3 116.46 6.86 (2H, dd, J 8.5 Hz) 115.5 6.92 (2H, dd, J 9 Hz) 4 159.42 158.2 5 116.46 6.86 (2H, dd, J 8.5 Hz) 115.5 6.92 (2H, dd, J 9 Hz) 6 130.03 7.37 (2H, d, J 8.5 Hz) 129.4 7.35 (2H, d, J 9.0 Hz) 1 102.22 4.04 (1H, d, J 1.2 Hz) 100.6 4.02 (1H, d, J 1.5 Hz) 2 71.76 69.3 3 73.78 3.10-3.84 70.4 3.1-3.80 (m, rhamnose) 4 72.17 70.7 5 70.54 71.9 6 17.83 1.20 (d, J 6.2 Hz) 18.0 1.03 (m) Compound 4: White amorphous solid; mp. 1650C. The IR spectrum of (4) exhibited hydroxyl absorption at 3493 cm−1 CH bonds at 2950 cm−1 and carbonyl at 1619 cm−1 (C=O. The ESI-MS of (4) provided the molecular formula C21H22O11 (observed m/z: 451 [M + H]+; calcd for C21H22O11). 67 Pham Thi Hong Minh, Nguyen Quyet Tien, Tran Thi Thanh Hang and Pham Huu Dien Table 2. 1H-NMR and 13C-NMR spectral data of (4) (in DMSO) Compound 4 3’,5,5’,7-Tetrahydroxyflavonone No -3-O-α-L-rhamnopyranoside [10] δC δH ppm (J Hz) δC (DMSO) δH ppm (J Hz) (DMOD) 2 79.92 5.54 (1H, d, J 2.5 Hz) 80.85 5.43 (1H, d, J 2.0 Hz) 3 73.32 4.21 (1H, d, J 2.5 Hz) 74.38 4.15 (1H, d, J 2.0 Hz) 4 193.02 193.64 5 163.94 163.94 6 96.15 5.92 (1H, d, J 2.0 Hz) 97.30 5.90 (1H, brs) 7 167.04 167.77 8 95.15 5.94 (1H, d, J 2.0 Hz) 96.20 5.92 (1H, brs) 9 162.44 163.30 10 100.26 101.19 1 126.34 127.38 2 114.06 6.84 (1H, d, J 1.2 Hz) 115.00 6.81 (1H, brs) 3 145.10 145.86 4 117.57 6.72 (1H, s) 118.87 6.70 (2H, brs) 5 144.93 145.62 6 115.07 6.74 (1H, s) 118.87 6.70 (2H, brs) 1 98.82 4.76 (1H, s) 99.55 4.74 (1H, s) 2 70.22 3.47 (1H, brs) 71.01 3.47 (1H, brs) 3 70.22 3.19 71.01 3.20 4 71.21 3.05 72.11 3.04 5 68.96 2.46 69.84 2.37 6 17.56 0.84 (3H, d, J 6.2 Hz) 18.11 0.79 (3H, d, J 6.0 Hz) 5- OH 11.74 (1H, s) 11.63 (1H, s) 13C-NMR and DEPT spectra of (4) show that molecular has a total of 21 carbon atoms, among them 8 quartenary carbon atoms at δC 126.34, 144.93, 145.10, 162.44, 163.94, 167.04 and 193.02; 12 methin groups (CH) at δC 68.96, 70.22, 70.22, 71.21, 73.32, 79.92, 95.15, 96.15, 98.82, 114.06, 115.07 and 117.57 and one methyl group (CH3) at δC 17.56. In the 1H-NMR spectra, proton signals of hydroxyl groups appear at δH 11.74 (5-OH) and δH at 8.85 (3,5-OH), 5 olefin protons belong to aromatic cycle B at δH 6.84 (d, J 1.2 Hz, H-2), 6.74 (1H, s, H-4), 6.72 (1H, s, H-6), 5.94 (1H, d, J 2.0 Hz, H-8) and 5.92 (1H, d, J 2.0 Hz, H-6) correlative with the carbon in succession at δ 114.06 (C-2), 117.57 (C-4), 115.07 (C-6), 95.15 (C-8) and 96.15 (C-6) in the 13C-NMR spectra. Other proton signals at δH/C 5.54 (d, J 2.5 Hz, H-2)/79.92 (C-2) and 4.21 (d, J 2.5 Hz, H-3)/73.32 (C-3) belong to cycle C, methin proton signal of rhamnose sugar moiety appears at δH/C 4.76 (brs, H-1)/98.82 (C-1). According to analysis of 68 Study on the chemical constituents in roots of Smilax glabra Roxb... 1H-NMR, 13C-NMR, DEPT, HSQC, HMBC spectra and spectral comparison with data of 3’,5,5’,7-tetrahydroxyflavanone-3-O-α-L-rhamnopyranoside in reference [10], compound 4 was elucidated as smitilbin. Compound 5: yellow amorphous solid; mp. 142 - 1430C. The ESI-MS of (5) provided the molecular formula C21H22O11 (observed m/z: 449 [M - H] +; calcd for C21H22O11). Table 3. 1H-NMR and 13C-NMR spectral data of (5) (in CD3OD) Compound 5 3’,4’,5,7-Tetrahydroxyflavonone No -3-O-α-L-rhamnopyranoside [8, 11] δC δH ppm (J Hz) (CD3OD) δC (CD3OD) δH ppm (J Hz) (CD3OD) 2 83.94 5.09 (1H, d, J 10.6 Hz) 84.8 5.12 (1H, d, J 9.8 Hz) 3 78.57 4.59 (1H, d, J 10.7 Hz) 79.4 4.52 (1H, d, J 9.5 Hz) 4 195.95 196.7 5 165.94 166.3 6 97.39 5.94 (1H, d, J 2.2 Hz) 98.2 5.84 (1H, d, J 1.5 Hz) 7 168.61 169.7 8 96.28 5.92 (1H, d, J 2.0 Hz) 97.2 5.86 (1H, d, J 1.2 Hz) 9 164.08 164.9 10 102.49 103.2 1 129.18 130.0 2 116.35 6.82 (1H, d, J 8.1 Hz) 117.1 6.83 (s) 3 146.53 147.3 4 147.36 148.1 5 115.50 6.97 (1H, d, J 1.8 Hz) 116.3 6.69 (brd, J 8.2 Hz) 6 120.48 6.86 (dd, J 1.8 and 8.2 Hz) 121.3 6.73 (d, J 8.2 Hz) 1 102.14 4.08 (1H, d, J 1.3 Hz) 102.9 4.02 (brs) 2 71.77 3.56 72.6 3.38 (brs) 3 72.17 3.67 72.9 3.42 4 73.81 3.34 74.6 3.13 5 70.51 4.25 71.3 3.81 (m) 6 17.83 17.83 (d, J 6.3 Hz) 18.6 1.01 (d, J 6.0 Hz) According to 1H-NMR, 13C-NMR, DEPT, HSQC, HMBC spectral data (see Table 3) and comparison with spectral data of 3’,4’,5,7-tetrahydroxyflavonone-3-O- α-L-rhamnopyranoside in [8, 11] references, compound 5 was elucidated as astilbin. 3. Conclusion Smilax glabra Roxb. is a medicinal plant of Vietnam to treat several dis- eases such as: piercing pain in the bones, detoxicating, scabies, nephritis, cystitis, syphilis,... From ethanol extracts of Smilax glabra Roxb. cultivating in Thai Nguyen, 69 Pham Thi Hong Minh, Nguyen Quyet Tien, Tran Thi Thanh Hang and Pham Huu Dien 5 compounds were isolated and structurally elucidated in the first time by various spectral methods, such as IR, MS, 1H-NMR, 13C-NMR, DEPT, HSQC, HMBC. They are stigmasta-5,22-diene-3β-ol (1), 3β-sitosterol-glucopyranoside (2), engeletin (3), smitilbin (4) and astilbin (5). Acknowledgements: This publication is completed with financial support from the Main point Project of Science and Technology, Theme Code: B2010-17-275TD. REFERENCES [1] Do Tat Loi, 2000. Medicinal plants and remedy of Vietnam. Medicine Publishing House, Hanoi, p. 498. [2] List of Vietnamese plants, Vol.III, Agriculture Publishing House (2005), 3, pp. 465-468. [3] Tran Van Loc, Tran Van Chien, Tran uc Quan, Pham Van Ly, Trinh Thi Thuy, Tran Van Sung, 2007. Isolation of dihydrokaempferol 3-O-L-rhamnopyranoside and astilbin from roots of Smilax glabra Roxb. and transfer them into aurenols. J. Science and Technology, Vol. 47 (3A), pp. 138-141. [4] Goad, L. J. and Akihisa, T., 1997. Analysis of sterols. Chapman & Hall, pp. 324-333. [5] P.K. Agrawal, 1989. Carbon -13 NMR of flavonoids. Studies in Organic Chem- istry 39. Elservier Science Publishing Company, pp. 133-135. [6] Dulce H.S. Silva, Massayoshi Yoshida and Massuo J. Kato, 1997. Flavonoids from Iryanthera sagotiana. Phytochemistry, Vol. 46, No. 3, pp. 579-582. [7] Johannes Reisch, Raouf A. Hussain and Iuliu Mester, 1984. Flavonoids from Flindersia australis. Phytochemistry, Vol. 23, No. 9, pp. 2114-2115. [8] John De Brito, Visuvasam Soosai Manickam, Subbarayan Gopalakrishnan, 1995. Determination of Aglycone Chirality in Dihydroflavonol 3-O-α-L-Rhamnosides by 1H-NMR Spectroscopy. Chem, Pharm, Bull, Vol. 43, No. 2, pp. 338-339. [9] Ryu S.H., Ahn B.Z., Pack M.Y., 1985. The cytotoxic principle of Scutellariae radix against L 1210 cells. Planta Medica, Vol. 51, pp. 355. [10] Tenji Konishi, Kiyonori Yamazoe, Masahiro Kanzato, Takao Konoshima and Yasuhiro Fujiwara, 2003. Three Diterpenoids (Excoecarins V1-V3) and a Flavanone Glycoside from the Fresh Stem of Excoecaria agallocha. Chem, Pharm, Bull, Vol. 51, No. 10, pp. 1142-1146. [11] Ting Chen, Jianxin Li, Jingsong Cao, Qiang Xu, Katsuko Komatsu and Tsuneo Namba, 1999. A new Flavanone Isolated form Rhizoma Smilacis glabrae and the Structural Requirements of its Derivatives for Preventing Immunologycal Hepatocyte Damage. Planta Med, Vol. 65, pp. 56-59. [12] Goad L. J. and Akihisa T., 1997. Analysis of sterols. Chapman & Hall, pp. 324-333. 70