A New Saponin from Mate, Ilex paraguariensis

Abstract

F a c u l a de F a d i a , Universia Federal do RioG r a d do SUI, Av. Ipirange, 2752, 90610 Port0 Alegre, RS, Brad and 0. SELIGMANN lnstitut f f i Phannazuttirche Siologie &r Unimikit Miinrhm, Karlstrase 29, D-8000 Mumben 2, West G m n y Assmcr.-Matesaponin 1, a new saponin obtained from the leaves of Ilexparaguarimsis, has been characterized by 'H nmr, 13C nmr, eims, fabms, and chemical reactions. The structure has been determined as ursolic acid-3-0-[f3-~-glucopyranosyl-( 1e3)-a-~-arabincpyranosyl)-(28~ l)-~-D-g~ucopyranosy~ ester.Ilex paraguariensis St. Hil. (Aquifoliaceae) is widely used as a traditional beverage known as mate (Paraguay tea) in southern Brazil, Argentina, Paraguay, and Uruguay. It is also used in popular medicines and employed in commercial herbal preparations as a stimulant to the central nervous system, a diuretic, and an antirheumatic. Apart from the wellknown xanthines, very little is known about its secondary metabolites (1). This paper reports the isolation and elucidation of the structure of a new saponin, named matesaponin 1, from the leaves of this medicinal plant.Matesaponin 1 was obtained from the n-BuOH extract through cc. After acid hydrolysis, the sugar components were identified as glucose and arabinose by tlc, whereas the identity of the aglycone moiety as ursolic acid was confirmed byThe eims of the acetyl derivative of matesaponin 1 showed peaks at mlz 438 and 331, which were attributed to the aglycone and the terminal hexose, respectively.The molecular mass of matesaponin 1 was shown to be 912 through fabms, which exhibited molecular ion peaks at m/z919EM+Li)+ and935 [M+Na]+. The fab mass spectrum, obtained in the negative ion mode, confirmed the molecular mass and gave information about the sequence of the sugars by the peaksatmlz911EM-H)-, 749[(M-H) -hexose)-, 587 [(M -H -hexose) H and 13C nmr (2-5). 1 -hexose)-, and 455 [(M -H -hexose -hexose) -pentose)-.The 'H-nmr spectrum of the acetyl derivative of matesaponin 1 showed three anomeric proton signals at 6 4.63 pprn (d,],,, = 8 Hz) and 6 4.3 1 ppm (d, ]1,2 = 8 Hz) attributed to glucose and arabinose, respectively, at C-3, and at 6 5.53 pprn (d,J1,,=8 Hz) corresponding to glucose at C-28 (6). These assignments were supported by the 13C-nmr spectrum of matesaponin 1, which showed three anomeric proton signals at 6 (pprn) 107.2, 106.0, and 95.5, the latter in full agreement with the presence of a f3-glucopyranose linked in the form of an ester (7-9). The f3 configuration for the two glucopyranosyl units and the CY configuration for the arabinopyranoside were inferred from the] values of the respective anomeric protons.The interglycosidic linkage was determined by the observed downfield shift (A6 9.3) for C-3 of the inner a-Larabinose, by comparing with the corresponding methylglycoside (10). This deshielding clearly indicated that the terminal glycosyl unit is attached at this position; the rest of the carbons were unaffected (Table 1).Matesaponin 1 on partial hydrolysis afforded a prosapogenin. Its fabms spectrum indicate...

HPLC method to assay total saponins in Ilex paraguariensis aqueous extract

“…From this solution, designed saponin fraction (SF), 1 mL was diluted to 10 mL with acetonitrile. This solution was filtered through a 0.45 µm membrane (Millipore, HVHP) 4,2005 and analyzed by HPLC. The evaluation was repeated three times.…”

“…1 Besides the substantial amounts of purine alkaloids 2 and caffeoyl-quinic acid derivatives, 3 the leaves of Ilex paraguariensis contain also a significant amount of triterpenoid saponins. Monodesmosidic and bidesmosidic saponins have been isolated from the aerial parts of Ilex paraguariensis, [4][5][6][7][8] all compounds containing the ursolic or oleanolic moieties ( Figure 1). These bitter and highly water-soluble compounds are likely to be partially responsible for the taste of the beverage 9 and also for foaming observed in the "mate".…”

“…These substances were previously isolated from Ilex paraguariensis leaves. 4 They were pure substances according to the 1 H and 13 C NMR spectra. …”

Foam-forming properties of Ilex paraguariensis (mate) saponin: foamability and foam lifetime analysis by Weibull equation

“…After the empirical linearization of the Weibull function (Equations 3 and 4), the intercept and slope calculated by the least squares method were compared by means of one-tail T test (P 0. (6) where: SQE is the regression standard deviation, S xx = S(x i --x) 2 , and n the sample size.…”

“…The occurrence, isolation and identification of the main saponins from mate leaves and fruits are well described in literature. [2][3][4][5][6][7][8][9] Mate saponins occur almost as bidesmosidic glycosides derived from oleanolic and ursolic acids having one or two sugar chains attached at the C-3 and C-28. 5 Alike other saponins from superior plants (e.g.…”