Gleditschiaside a, a new carbohydrate ester of cinnamic acid from the leaves of gleditschia australis hemsl

Journal of Chemistry, Vol. 45 (special issue), P. 111 - , 2007<br /> <br /> <br /> GLEDITSCHIASIDE A, A NEW CARBOHYDRATE ESTER OF<br /> CINNAMIC ACID FROM THE lEAVES OF GLEDITSCHIA<br /> AUSTRALIS HEMSL.<br /> Received 15 October 2007<br /> PHAN VAN KIEM, NGUYEN THI HONG VAN, NGUYEN THE DUNG, CHAU VAN MINH<br /> Institute of Natural Products Chemistry, VAST<br /> <br /> SUMMARY<br /> A new carbohydrate ester of cinnamic acid named gleditschiaside A was isolated from the<br /> methanolic extract of the leaves of Gleditschia australis Hemsl., (Caesalpiniaceae). Its structure<br /> was elucidated by means of ESI-mass spectrometry, 1H-NMR, 13C-NMR (CPD and DEPT), HSQC<br /> and HMBC spectra in comparison with the literature.<br /> <br /> I - INTRODUCTION Products Chemistry (INPC), VAST.<br /> 2. General experimental procedures<br /> In previous papers, we have reported the<br /> isolation and the structural elucidation of the Melting points were determined using an<br /> new cinnamic acid derivative [1], 5-O- Electro thermal IA-9200. The IR spectra were<br /> caffeoylquinic acid and cinnamic acid [2], and obtained on a Hitachi 270-30 type spectrometer<br /> flavonoid constituents [3] from Gleditschia with KBr discs. Optical rotations were<br /> australis Hemsl., (Caesalpiniaceae). This paper determined on a Jasco DIP-1000 KUY polari<br /> deals with the isolation and structural meter. The electrospray ionization (ESI) mass<br /> determination of a new carbohydrate ester of spectra were obtained using an AGILENT 1100<br /> cinnamic acid named gleditschiaside A from the LC-MSD Trap spectrometer. The 1H-NMR (500<br /> same source. Its structure was elucidated as 1- MHz) and 13C-NMR (125 MHz) spectra were<br /> O-trans-cinnamoyl- -L-rhamnopyranosyl- recorded on a Bruker AM500 FT-NMR<br /> (1 6)- -D-glucopyranose (1) by means of ESI- spectrometer and TMS was used as an internal<br /> mass spectrometry, 1H-NMR, 13C-NMR (CPD standard. Column chromatography (CC) was<br /> and DEPT), HSQC and HMBC spectra in performed on silica gel (Kieselgel 60, 70-230<br /> comparison with the literature. mesh and 230-400 mesh, Merck) and YMC RP-<br /> 18 resins.<br /> II - EXPERIMENTAL 3. Extraction and isolation<br /> 1. Plant material Dried leaves of G. australis were powdered<br /> and then extracted three times with MeOH. The<br /> The leaves of G. australis Hemsl. were MeOH extract (70 g) was suspended in water<br /> collected in Tam Dao Mountain, Vinh Phuc and partitioned in turn with n-hexane,<br /> province, Vietnam and was identified by Dr chloroform, ethyl acetate, and n-BuOH to obtain<br /> Tran Huy Thai, Institute of Ecology and n-hexane, chloroform, ethyl acetate, and n-<br /> Biological Resources, VAST. The voucher of BuOH fractions. The n-BuOH fraction (8.0 g)<br /> specimen was deposited at Institute of Natural was chromatographed on silica gel column<br /> using CHCl3-MeOH-H2O (30:10:1) and on The sugar residue was then dissolved in 1 ml<br /> YMC column using MeOH-H2O (3:1) to yield anhydrous pyridine, 2 mg L-leucine methyl<br /> compounds 1 (35 mg) as amorphous powder. ester hydrochloride was added, and the mixture<br /> was warmed at 60oC for 1 h. Then 2 mg NaBH4<br /> 1-O-trans-cinnamoyl- -L- were added, and the mixture was stirred for 1 h<br /> rhamnopyranosyl-(1 6)- -D-glucopyranose at ambient temperature. Then 0.2 ml of<br /> (gleditschiaside A, 1): Amorphous powder., trimethylsilylation reagent trimethylchlorosilane<br /> mp. 168 - 170oC; [ ]25D -42o; IR (KBr) max cm-1: was added and warming at 60oC was continued<br /> 3250 - 3435 (OH), 1712 (>C=O, ester), 1635 for another 30 min. The leucine derivatives were<br /> (C=C), 1030 (C-O-C); ESI-MS m/z: 479 subjected to GC analysis to identify the sugars.<br /> [M+Na]+; 455 [M-H]- (C21H28O11); 1H-NMR Column temperate 200oC; injection temperate<br /> (500 MHz, CD3OD) and 13C-NMR (125 MHz, 250oC; carrier gas N2 at flow rate of 32.2<br /> CD3OD): see Table 1. ml/min; derivatives of D-glucose and L-<br /> Acid Hydrolysis of 1 [5]: Compound 1 (4 rhamnose 13.91 and 8.88 min, respectively.<br /> mg) in 10% HCl-dioxane (1 : 1, 1 ml) were<br /> heated at 80oC for 4 h in water bath. The III - RESULTS AND DISSCUSSION<br /> reaction mixture was neutralized with Ag2CO3,<br /> filtered, and then extracted with CHCl3 (1 ml). Compound 1 was isolated from the<br /> The CHCl3 layer afforded cinnamic acid methanolic extract of the leaves of G. australis<br /> comparing by TLC [n-hexane-acetone (3 :1), Rf Hemsl. The IR spectrum exhibited the presence<br /> = 6.3] with authentic sample. After of OH, >C=O, C=C and C-O-C groups at max<br /> concentration, the water layer was examined by 3250-3435, 1712, 1635, 1030 cm-1, respectively.<br /> TLC with CHCl3-MeOH-H2O (55 : 45 : 10) and The 13C-NMR and DEPT spectra (Table 1)<br /> compared with authentic samples. revealed the presence of 21 carbon atoms (1 ×<br /> Determination of Sugar Components: The CH2, 17 × CH, 2 × C and 1 × CH3). Analysis the<br /> monosaccharide subunits were obtained by NMR spectra, the presence of a disaccharide<br /> hydrochloric acid hydrolysis as described above. moiety in the upfield range (12 resonances) and<br /> a downfield cinnamoyl group was suggested.<br /> <br /> 6"<br /> H3C<br /> 4" OHO<br /> OR 5"<br /> <br /> 1 R= HO<br /> 3 HO<br /> 4' 6' 2 4 2"<br /> 5' O 8<br /> 3"<br /> 1<br /> HO 2' O 9 7 6<br /> 5<br /> OH<br /> 3' 1'<br /> HO<br /> OH O<br /> O 1a R = HO<br /> HO<br /> OH<br /> <br /> Figure 1: Structures of 1 and 1a<br /> <br /> Comparing the NMR spectra of 1 with those resonance at 6.57 and 7.82 (1H, each, J = 16.0<br /> of 1-O-trans-cinnamoyl- -D-glucopyranosyl- Hz) were attributable to trans-olefinic protons.<br /> (1 6)- -D-glucopyranose [4] (table 1) A doublet at 5.6 (1H, J = 7.5 Hz) indicated a<br /> suggested that the sugars moiety of 1 were a -configurated anomeric proton (vicinal H-1 /2<br /> glucopyranose and a rhamnopyranose. The 1H- in trans position). A broad-singlet at 4.74 (1H)<br /> NMR spectrum of 1 clearly confirmed the indicated a -configuration anomeric proton<br /> presence of a trans-cinnamic acid. Proton (vicinal H-1 /2 in trans position). A methyl<br /> group of the rhamnopyranose was assigned at C that the rhamnopyranose linked to C-6 of the<br /> 17.95/ H 1.28 (d, J = 6.5 Hz), and an glucopyranose by ether kinkage, and C-1 of the<br /> oxymethylene group of the glucopyranosyl was glucopyranose linked to C-9 of cinnamic acid<br /> assigned at C 67.73/ H 4.00 (d, J = 10.0 Hz) by ester linkage. Acid hydrolysis of 1 afforded<br /> and 3.68 (overlapped). The H-C connections in cinnamic acid, D-glucose and L-rhamnose.<br /> the structure of 1 were deduced from the HSQC Furthermore, the ESI-MS spectrum of 1<br /> and the partial structure of 1 were deduced from exhibited the quasi ion peaks at m/z (positive)<br /> the results of HMBC spectrum in comparison 479 [M+Na]+; (negative) 455 [M-H]-<br /> with the NMR data of 1-O-trans-cinnamoyl- - corresponding to the molecular formula of<br /> C21H28O11. From the above data, compound 1<br /> D-glucopyranosyl-(1 6)- -D-glucopyranose<br /> [4]. In the HMBC, proton H-1 ( 5.60) was determined to be 1-O-trans-cinnamoyl- -<br /> correlated with C-9 ( 167.00), and proton H-1 L-rhamnopyranosyl-(1 6)- -D-glucopyranose,<br /> and named as gleditschiaside A, a new natural<br /> ( 4.75) correlated with C-6 ( 67.73) indicated<br /> product.<br /> <br /> Table 1: NMR data of 1 and 1a<br /> 1<br /> Pos. 1ae a,c a,b<br /> C DEPT H (J, Hz) HMBC<br /> Cinnamic acid 1 136.4 135.54 - - -<br /> 2,6 131.3 129.36 CH 7.63 (m) C-1, C-7<br /> 3,5 131.9 130.03 CH 7.43 (m) C-1<br /> 4 134.0 131.77 CH 7.43 (m)<br /> 7 150.8 147.66 CH 7.82 (d, 16.0) C-1, C-8, C-9<br /> 8 118.7 118.19 CH 6.57 (d, 16.0) C-1, C-7, C-9<br /> 9 169.9 167.00 - - -<br /> Glucose 1 96.9 95.84 CH 5.60 (d, 7.5) C-9, C-2 , C-3<br /> 2 75.8 73.95 CH 3.46 (dd, 7.5, 8.0) C-1 , C-4<br /> 3 78.4 77.91 CH 3.50 (dd, 9.0, 8.0) C-1 , C-4 , C-5<br /> 4 72.3 71.14 CH 3.42 (dd, 9.0, 9.0) C-2 , C-5 , C-6<br /> 5 78.1 77.73 CH 3.58 (m) C-3 , C-6<br /> 6 70.9 67.73 CH2 4.00 (d, 10,0) C-5 , C-1<br /> 3.68* C-5 , C-1<br /> Other sugar 1 105.3 102.20 CH 4.74 (br s) C-6 , C-2<br /> 2 74.7 69.77 CH 3.70*<br /> 3 78.5 73.95 CH 3.37*<br /> 4 71.7 72.07 CH 3.70*<br /> 5 78.6 72.31 CH 3.87 (m) C-4 , C-6<br /> 6 63.5 17.95 CH3 1.28 (d, 6.5) C-4 , C-5<br /> a b c d<br /> Measured in CD3OD 125 MHz, 500 MHz, Measured in D2O, Chemical shift ( ) in ppm,<br /> *Overlapped signals, e C of 1a [4].<br /> Acknowledgments: The authors would like to 3. N. T. H. Van, P. V. Kiem, C. V. Minh, N. T.<br /> thank Dr Tran Huy Thai, Institute of Ecology Dung, 5-O-caffeoylquinic acid and cinamic<br /> and Biological Resources, VAST for the plant acid from Gleditschia australis Hemsl.,<br /> identification. (Caesalpiniaceae), Vietnamese Journal of<br /> Chemistry, accepted (2007).<br /> REFERENCES 4. S. Latza, D. Ganber and R. Berger,<br /> Carbohydrate esters of cinnamic acid from<br /> 1. P. V. Kiem, N. T. H. Van, P. K. Tiep, C. V. fruits of Physalis peruviana, Psidium<br /> Minh, L. M. Huong, N. D. Tomasi, A. guajava and Vaccinium Vitis-Idaea,<br /> Braca, A new E-cinnamic acid derivative Phytochemistry, Vol. 43(2), 481-485<br /> from Gleditschia australis Hemsl., (1996).<br /> Vietnamese Journal of Pharmacy, Vol. 5. Ito, H. B. Chai, L. B. S. Kardono, F. M.<br /> 372(4), 33-36 (2007). Setowati, J. J. Afriastini, N. R. Farnsworth,<br /> 2. N. T. H. Van, P. V. Kiem, C. V. Minh, N. T. G. A. Cordell, J. M. Pezzuto, S. M.<br /> Dung. Vietnamese Journal of Pharmacy, Swanson, A. D. Kinghorm, J. Nat. Prod.,<br /> 379(11), 36-39 (2007). Vol. 67, 201-205 (2004).<br /> 6.<br /> <br /> <br /> <br /> Gleditschiaside A, mét cacbohydrat este míi cña axit cinnamic tõ l¸ c©y bå kÕt Gleditschia australis<br /> Hemsl.<br />