3-methyl-1-buten-3-yl-6-o--xylopyranosyl--D-gluco- pyranoside from Paederia scanders

Journal of Chemistry, Vol. 44 (1), P. 88 - 90, 2006<br /> <br /> <br /> 3-methyl-1-buten-3-yl-6-o- -xylopyranosyl- -D-gluco-<br /> pyranoside from Paederia scanders<br /> Received 26 August 2004<br /> Dang Ngoc Quang1, Nguyen Xuan Dung2<br /> 1<br /> Faculty of Chemistry, Hanoi University of Education<br /> 2<br /> Faculty of Chemistry, College of natural Science, VNU<br /> <br /> <br /> Summary<br /> 3-methyl-1-buten-3-yl-6-o- -xylopyranosyl- -D-glucopyranoside has been isolated from the<br /> methanolic extract of the roots of Vietnamese Paederia scanders. Its structure was elucidated by<br /> the combination of 2D NMR, IR and high resolution FAB-MS spectroscopy and chemical<br /> reaction, such as acetylation.<br /> <br /> <br /> <br /> I - Introduction NMR spectra were recorded on Varian<br /> Unity 600 (600 MHz), using either CDCl3 or<br /> Paederia scanders (Lour.) Merril belonging CD3OD as solvent. Mass spectra including high-<br /> to Rubiaceae widely grows in East Asia, such as resolution and high-resolution FAB mass<br /> Vietnam, China, Japan, and Philippines [1]. The spectra were recorded on a JEOL JmS AX-500<br /> aerial parts of this plant are utilized for diuretic, spectrometer. IR spectra were measured on<br /> emetic, rheumatic arthritis and curing bacillary JASCO FT/IR-5300 spectrophotometer. The<br /> dysentery, while the young leaves are eaten as specific optical rotations were measure on a<br /> vegetable [2, 3]. Previously, several glucosides, JASCO DIP-1000 polarimeter with CHCl3 as<br /> such as paederoside, paederosidic acid, solvent. HPLC was performed on Shimadzu<br /> asperuloside, and scandoside, et al. have been liquid chromatography LC-10 AS with RID-6A<br /> isolated from the leaves and sterm of P and SPD-10A detectors using a Waters 5C 18-<br /> scandens [4, 5]. Later, some of which performed AR-II column. TLC was performed on silica gel<br /> the inhibitory effect on Epstein-Barr virus plates (Kiesegel 60 F254, Merck) and reversed<br /> activation [3]. In the course of our inverstigation phase C18 silica gel plates (Merck).<br /> of the biologically active compounds from 2. Materials<br /> Vietnamese medicinal plants, we reported the<br /> isolation and structural elucidation of three Fresh roots of Paederia scandens (Lour.)<br /> sulfur-containing bis-iridoid glucosides and two Merril were collected in Hanoi, Vietnam in July<br /> iridoid glucosides from the roots of Vietnamese 2000 and then identified by Dr. Tran Ngoc Ninh<br /> P. scandens [6]. In continuation, a new (Institute for Ecology and Natural Resources,<br /> glycoside is reported in this paper. Hanoi Vietnam). The vourcher specimen (VN<br /> 02001) has been deposited in Faculty of<br /> II - Experimental Pharmaceutical Sciences, Tokushima Burin<br /> University Japan.<br /> 1. General 3. Extraction and isolation<br /> 88<br />  The roots of P. scandens (3.2 kg) were dried Positive FAB-MS: 403 [M+Na]+. HR-FABMS:<br /> at room temperature and powdered, the extracted m/z 403.1562 (C16H28O10Na, requires m/z<br /> with MeOH using Soxhlet apparatus. The MeOH 403.1580). IR (KBr): 3390, 2979, 2927, 1645,<br /> extract was concentrated to give a residua (118.6 1417, 1366, 1264, 1087, 928 cm-1. 1H and 13C-<br /> g), which was partitioned between butanol and NMR (CD3OD) (table 1).<br /> water. The butanol layer was concentrated to Acetylation of 1: Compound 1 (14.5 mg) was<br /> give (57.2 g) a stick residue. The butanolic acetylated with Ac2O in pyridine. Work up as<br /> extract (19.79 g) was chromatographed on silica usual gave compound 2 (12.9 mg). [ ]20D - 33.5o<br /> gel column, using CHCl3-MeOH-H2O (65 15 :<br /> (c 1.13, CHCl3). Positive FAB-MS: 655<br /> 10, lower phase) as eluent resulted in the<br /> [M+Na]+. HR-FABMS: m/z 655.2234<br /> isolation of 6 fractions. Fraction 6 (683 mg) was<br /> (C28H40O16Na, requires m/z 655.2214). IR<br /> purified repeatedly by reversed phase preparative<br /> (KBr): 2926, 2853, 1752, 1714, 1640, 1433,<br /> HPLC, H2O-MeOH (1.5 : 1) as solvent system to<br /> 1369, 1221, 1039, 910 cm-1. 1H and 13C NMR<br /> give 1 (22.2 mg). [ ]D20 - 47.6o (c 0.84, CHCl3). (CDCl3) (table 1).<br /> <br /> Table 1: 1H and 13C NMR spectral data for 1 (CD3OD) and 2 (CDCl3)<br /> Compound 1 Compound 2<br /> Position 1 13 1 13<br /> H C H C<br /> 5.12 (dd, 1.4, 11.0) 5.18 (dd, 0.8, 11.0)<br /> 1 114.5 114.9<br /> 5.22 (dd, 1.4, 17.9 5.19 (dd, 0.8, 17.6)<br /> 2 6.02 (dd, 11.0, 17.9) 145.2 5.81 (dd, 11.0, 17.6) 142.7<br /> 3 79.2 78.5<br /> 4 1.38 s 26.6 1.33 s 26.0<br /> 5 1.33 s 27.9 1.27 s 27.3<br /> 1’ 4.32 (d, 8.0) 99.6 4.53 (d, 8.0) 95.8<br /> 2’ 3.14 (dd, 8.0, 9.1) 75.1 4.92 (dd, 8.0, 9.9) 71.4<br /> 3’ 3.33 m 78.0 5.13 (t, 8.2) 73.0<br /> 4’ 3.31 (t, 8.8) 71.5 4.88 (t, 9.6) 68.7<br /> 5’ 3.34 m 76.6 3.62 m 73.0<br /> 4.01 (dd, 1.4, 11.6) 3.35 (dd, 8.5, 11.8)<br /> 6’ 69.7 61.9<br /> 3.71 (dd, 4.8, 11.6) 4.13 (dd, 4.9, 11.8)<br /> 1’’ 4.30 (d, 7.4) 105.4 4.55 (d, 6.6) 100.2<br /> 2’’ 3.20 (dd, 7.4, 9.1) 74.9 5.17 m 71.4<br /> 3’’ 3.30 m 77.6 4.92 m 70.6<br /> 4’’ 3.48 m 71.2 3.94 m 69.1<br /> 3.86 (dd, 5.5, 11.6) 3.58 (dd, 7.1, 10.4)<br /> 5’’ 66.8 67.6<br /> 3.99 (dd, 10.4, 11.6) 3.77 (dd, 1.7, 10.4)<br /> 1.99 s, 2.02 s, 2.04 s, 169.2, 69.3, 169.6,<br /> CH3CO<br /> 2.05 s, 2.05 s, 2.05 s 169.8, 170.1, 170.3<br /> <br /> III - Results and discussion Butanoic layer was concentrated and purified by<br /> using a combination of silica gel column<br /> The crude methanol extract of P.scandens chromatography and preparative reversed-phase<br /> was partitioned between butanol and water. HPLC to give a new glycoside as showed in the<br /> <br /> 89<br /> experimental section. Thanks are also due to Prof. Y. Asakawa and<br /> The FAB-MS spectrum of 1 showed the Dr. T. Hashimoto (TBU, Japan) for their help<br /> molecular peak at 403 [M + Na]+ and the high and valuable discussions.<br /> solution FAB-MS indicated the molecular<br /> formula of C16H28O10. Its 1H- and 13C NMR 4'' 5''<br /> spectrum (table 1) revealed the signals of three O<br /> RO 1'' O 6' 4 5<br /> olefinic protons, two singlet methyls, together OR 3'' 2''<br /> OR 4' 5' O<br /> with 13CH- protons arising from sugar moieties.<br /> The 13C-NMR spectrum of 1 exhibited 16 carbon 1' O 3<br /> RO 2<br /> RO 3' 2'<br /> signals due to 5 carbons of an aglycone and 11 OR<br /> sugar carbons as summaried in table 1. 1<br /> Investigation of 1H-1H COSY and HMBC spectra<br /> (figure 2) of the aglycone of 1 showed that it is 1. R = H; 2. R = Ac<br /> 3-methyl-1-butene which was connected with Figure 1: Structure of 1 and 2<br /> the first sugar moiety at C-3 by the HMBC<br /> correlation between H-1’ and C-3. The large<br /> coupling constant of the anomeric proton (<br /> 4.32, 1H, d, J = 8.0 Hz, H-1’) in the 1H NMR<br /> spectrum suggested the presence of a<br /> glucopyranosyl moiety [6]. The identification of<br /> the remaining sugar moiety was partly<br /> established by interpretation of its 2D NMR<br /> spectrum, in which another anomeric proton (<br /> 4.30, 1H, d, J = 7.4 Hz, H-1’’) has a big coupling<br /> constant and partly by comparing with those of Figure 2: The important HMBC<br /> previous literature [7] indicated that it was -D- correlations of 1<br /> xylopyranose. The linkage between two sugars<br /> was clearly detected by the correlation between References<br /> H-1’’ and C-6’ in the HMBC spectrum (figure<br /> 2). Acetylation of 1 with acetic anhdydride in 1. S. Kadota. Investigation on Natural Drug<br /> pyridine resulted in the formation of hexaacetate Resources, 16 - 68 (2000).<br /> (2). Its molecular formula was found to be 2. N. N. Tran. J. of Biology (Vietnam), 9, 40 -<br /> C28H40O16 by HR-FABMS indicating that 1 44 (1987).<br /> contain six hydroxyl groups.<br /> 3. G. J. Kapadia, S. C. Sharma, H. Tokuda, H.<br /> From the above discussion, 1 was Nishino and S. Ueda. Cancer Lett., 102, 223<br /> determined to be 3-methyl-1-buten-3-yl-6-o- - - 226 (1996).<br /> D-xylopyrnosyl- -D-glucopyranoside as shown 4. H. Inouye, S. Inouye, N. Shimokawa and M.<br /> in figure 1. Previously, many iridiod glucoside Okigawa. Chem. Pharm. Bull., 17, 1942 -<br /> have been isolated from P. scandens around the 1948 (1969).<br /> worlk [3, 4]. However, this is the first report of<br /> glycoside from P. scandens. 5. H. Inouye, S. Saito, H. Taguchi and T. Endo.<br /> Tetrahedron Lett., 28, P. 2347 - 2350 (1969).<br /> Acknowledgements: The author thanks Miss Y. 6. N. D. Quang, T. Hashimoto, M. Tanaka, N.<br /> Okatomo and Dr. M. Tanaka (Tokushima Bunri X. Dung and Y. Asakawa. Phytochemistry,<br /> University, Japan) for the recording Mass and 60, 505 - 514 (2002).<br /> NMR spectra, and Dr Tran Ngoc Ninh 7. S. Yamamura, K. Ozawa, K. Ohtani, R.<br /> (Institute for Ecology and Natural Resources, Kasai and K. Kamasaki. Phytochemistry,<br /> Hanoi, Vietnam) for identification of the plant. 48, P. 131 - 136 (1998).<br /> 90<br /> 91<br />