“…The 13 C NMR spectrum contained 46 resonances; 30 of them, attributed to the sapogenol moiety, were in good agreement with cyclocanthogenin. 5 Full assignment of the 1 H and 13 C signals of the aglycon part of 1, secured by 1 H-1 H DQF-COSY and HSQC spectra, showed marked glycosylation shifts for C-3 (δ 90.1) and C-6 (δ 80.4). All connectivities within 1 were also confirmed by a HMBC experiment.…”
Section: Resultsmentioning
confidence: 93%
“…The known saponins were identified as cycloastragenol, 6 astragaloside I, 6 astragaloside II, 6 astragaloside IV, 6 and cyclocanthoside E 5 by spectral data and comparison of their physical properties with those reported previously for these compounds. 5,6 Compounds 3, 4, and cycloastragenol were isolated from A. microcephalus, whereas compounds 1-3 and the other saponins, except 4, were isolated from A. brachypterus.…”
Three new cycloartane-type triterpene glycosides, brachyosides A (1), B (3), and C (2), from the roots of Astragalus brachypterus and one new glycoside, cyclocephaloside II (4), from the roots of Astragalusmicrocephalus have been isolated together with five known saponins, astragalosides I, II, and IV, cyclocanthoside E, and cycloastragenol. The structures of the new compounds were established as 3-O-[beta-D-xylopyranosyl(1-->3)-beta-D-xylopyranosyl-6-O-beta-D-gluc opyranosyl-3beta,6alpha,16beta,24(S),25-pentahydrox ycycloartane (1), 3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-24-O-beta-D-glucop yranosyl-3beta,6alpha,16beta,24(S),25-pentahydroxyc ycloartane (2), 20(R),24(S)-epoxy-6-O-beta-D-glucopyranosyl-3beta,6alpha,16beta , 25-tetrahydroxycycloartane (3), and 20(R), 24(S)-epoxy-3-O-(4'-O-acetyl)-beta-D-xylopyranosyl-6-O-beta-D-glucopy ranosyl-3beta,6alpha,16beta,25-tetrahydroxycycloart ane (4). For the structure elucidations, 1D- and 2D-NMR experiments and FABMS were used.
“…The 13 C NMR spectrum contained 46 resonances; 30 of them, attributed to the sapogenol moiety, were in good agreement with cyclocanthogenin. 5 Full assignment of the 1 H and 13 C signals of the aglycon part of 1, secured by 1 H-1 H DQF-COSY and HSQC spectra, showed marked glycosylation shifts for C-3 (δ 90.1) and C-6 (δ 80.4). All connectivities within 1 were also confirmed by a HMBC experiment.…”
Section: Resultsmentioning
confidence: 93%
“…The known saponins were identified as cycloastragenol, 6 astragaloside I, 6 astragaloside II, 6 astragaloside IV, 6 and cyclocanthoside E 5 by spectral data and comparison of their physical properties with those reported previously for these compounds. 5,6 Compounds 3, 4, and cycloastragenol were isolated from A. microcephalus, whereas compounds 1-3 and the other saponins, except 4, were isolated from A. brachypterus.…”
Three new cycloartane-type triterpene glycosides, brachyosides A (1), B (3), and C (2), from the roots of Astragalus brachypterus and one new glycoside, cyclocephaloside II (4), from the roots of Astragalusmicrocephalus have been isolated together with five known saponins, astragalosides I, II, and IV, cyclocanthoside E, and cycloastragenol. The structures of the new compounds were established as 3-O-[beta-D-xylopyranosyl(1-->3)-beta-D-xylopyranosyl-6-O-beta-D-gluc opyranosyl-3beta,6alpha,16beta,24(S),25-pentahydrox ycycloartane (1), 3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-24-O-beta-D-glucop yranosyl-3beta,6alpha,16beta,24(S),25-pentahydroxyc ycloartane (2), 20(R),24(S)-epoxy-6-O-beta-D-glucopyranosyl-3beta,6alpha,16beta , 25-tetrahydroxycycloartane (3), and 20(R), 24(S)-epoxy-3-O-(4'-O-acetyl)-beta-D-xylopyranosyl-6-O-beta-D-glucopy ranosyl-3beta,6alpha,16beta,25-tetrahydroxycycloart ane (4). For the structure elucidations, 1D- and 2D-NMR experiments and FABMS were used.
“…Similarly, long-range correlations between C-1‘ (δ 105.4 d) and H-3 (δ 3.69) and C-1‘‘ (δ 106.4 d) and H-24 (δ 3.44, dd, J = 9.2, 1.8 Hz) were observed. 1 H- and 13 C-NMR data for H-24 and C-24 are comparable to those reported for analogous compounds having a 24 S configuration. , 1 Fragments of 2 Deduced from 2D-NMR Measurements …”
Section: Resultsmentioning
confidence: 99%
“…The roots of various Astragalus species represent very old and well-known drugs in traditional medicine, used for antiperspirant, diuretic, and tonic purposes and for the treatment of nephritis, diabetes, leukemia, and uterine cancer . Previous studies performed on this genus have resulted in the isolation of a series of cycloartane-type triterpenoid glycosides. − Also reported for Astragalus species are their antiinflammatory, analgesic, diuretic, hypotensive, sedative, and cardiotonic activities . The current report describes the isolation and structure elucidation of four novel cycloartane-type triterpene glycosides named as macrophyllosaponins A ( 1 ), B ( 2 ), C ( 3 ), and D ( 4 ) from the roots of Astragalus oleifolius DC.…”
Four novel cycloartane-type triterpene glycosides, macrophyllosaponins A-D (1-4) were isolated from the roots of Astragalus oleifolius. By means of chemical (acetylation, alkaline hydrolysis) and spectroscopic methods (IR, 1D- and 2D-NMR, FABMS), their structures were established as 3-O-alpha-L-rhamnopyranosyl-24-O-(4"-O-acetyl)-beta-D-xylopyranosyl-1 alpha,3 beta,7 beta,24(S), 25-pentahydroxycycloartane (1), 3-O-alpha-L-rhamnopyranosyl-24-O-beta-D-xylopyranosyl-1 alpha,3 beta, 7 beta,24(S), 25-pentahydroxycycloartane (2), 3-O-alpha-L-rhamnopyranosyl-25-O-beta-D-glucoyranosyl-1 alpha, 3 beta,7 beta,24(S),25-pentahydroxycycloartane (3), and 3-O-alpha-L-rhamnopyranosyl-24-O-(2-O-beta-D-xylopyranosyl) -beta-D-xylopyranosyl-1 alpha,3 beta,7 beta,24(S), 25-pentahydroxycycloartane (4).
“…Thus, 2 appeared to have an acyclic side chain. The configuration of the C-24 chiral center was determined by comparing the 13 C NMR spectral data of compound 2 and of cyclocanthosides A, B, C, E, and G. 5 The C-24 atom, having the S-configuration, 5 resonates at δ 77.1. In contrast, the C-24 atom, having the R-configuration, resonates at δ 80.5.…”
A novel cycloartane-type glycoside, cyclocephaloside I (1) was isolated from the roots of Astragalus microcephalus in addition to known glycosides cyclocanthoside E (2) and astragaloside IV (3). The structure of 1 was determined by spectral (IR, 1 H and 13 C NMR, and FABMS) and chemical (acetylation) methods and established as 20,25-epoxy-3β-(β-D-xylopyranosyl)oxy-6R-(β-D-glucopyranosyl)oxy-cycloartane-16β,24R-diol.In the flora of Turkey, the genus Astragalus (Leguminosae) is represented by approximately 380 species, which are listed under several sections. 1 Astragalus species, growing wild in Turkey, are of economical importance. Gum tragacanth is a very well-known foodstuff and pharmaceutical emulsifier, derived from Astragalus species. In Turkey, A. microcephalus is primarily used for the production of tragacanth. 2 Recently, we reported the isolation of eight cycloartane saponins from Astragalus melanophrurius Boiss., which were found to stimulate lymphocyte transfer in vitro, 3 and four novel cycloartane saponins from Astragalus oleifolius DC. 4 This paper describes the isolation and structure elucidation of a novel cycloartane-type glycoside, cyclocephaloside I (1), in addition to known glycosides cyclocanthoside E (2) 5 and astragaloside IV (3) 6 from the roots of A. microcephalus Willd.The water-soluble part of the 80% aqueous ethanolic extract of the roots of A. microcephalus was first fractionated on Si gel. The fraction rich in saponins was subjected to medium-pressure liquid chromatography (MPLC) using LiChroprep C-18 as stationary phase and eluting with MeOH-H 2 O mixtures (60-75% MeOH in H 2 O) to yield the compounds 1, 2, and 3, respectively.The IR spectrum of 1 showed hydroxyl absorption bands. The FABMS of 1 exhibited quasimolecular ion peaks at m/z 807 [M + Na] + and at m/z 1569 [2 M + H] + , which are compatible with the molecular formula C 41 H 68 O 14 . The 1 H NMR spectrum of 1 showed characteristic signals due to cyclopropane-methylene protons as an AX system (δ 0.16 and 0.54, AX system, J AX ) 4.0 Hz; H 2 -19) and seven tertiary methyl groups. Additionally, the resonances for two anomeric protons were observed at δ 4.80 (d, J ) 7.4 Hz) and 4.87 (d, J ) 7.6 Hz). Thus, compound 1 was considered to be a cycloartane-type triterpene diglycoside. This observation was supported by the 13 C NMR spectral data of 1. The NMR signals were analyzed by the use of COSY and TOCSY coupled with HMQC. The 1 H and 13 C NMR data supported the assignment of the sugar moieties in 1 as β-D-xylopyranose and β-D-glucopyranose.
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