The configuration and conformation of the arabinose moiety in platycodins, saponins isolated from , and mi-saponins from based on carbon-13 and hydrogen-1 nmr spectroscopic evidence: The total structures of the saponins

Ishii, Hiroshi; Kitagawa, Isao; Matsushita, Kazuhiro; Shirakawa, Kamon; Tori, Kazuo; Tozyo, Takehiko; Yoshikawa, Masayuki; Yoshimura, Y.

doi:10.1016/s0040-4039(01)90369-7

Cited by 68 publications

(49 citation statements)

References 7 publications

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“…Finally, shift values (6 66.5 and 6 64.2) attributed (Table 1, Py-d,) to A-4 and A-5, respectively, accorded neither with the corresponding values (6 69.1 and 6 66.6, respectively) given for reference methyl a-L-arabinopyranoside nor with the values (6 70.8 and 6 63.9, respectively) given (21) for methyl P-L-arabinopyranoside. However, we have found shifts similar to those reported (19) for carbons 4 and 5 of the 2-linked a-arabinopyranose units of a series of glycosides. In conclusion, a-configuration of the arabinose unit in muscaroside A rests only on the evidence afforded by the application of Klyne's rule.…”

supporting

confidence: 87%

Glycosides from Muscaricomosum. 4. Structure of muscaroside A

Adinolfi¹,

Barone²,

Lanzetta³

et al. 1983

Can. J. Chem.

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supporting

confidence: 87%

Glycosides from Muscaricomosum. 4. Structure of muscaroside A

Adinolfi¹,

Barone²,

Lanzetta³

et al. 1983

Can. J. Chem.

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“…The small 3 J H-1,H-2 coupling constant (3.0 Hz) for the anomeric proton of the arabinopyranosyl moiety of the trisaccharide chain at C-3 suggests that it has a 1 C 4 conformation rather than the usual 4 C 1 conformation. [20][21][22] Furthermore, the other coupling constants assignable to the remaining signals for the arabinopyranosyl moiety were in good agreement with those reported in the literature. 20,22) Thus the structure of the echinosophoroside B (2) was deter-…”

supporting

confidence: 89%

“…The HR-FAB-MS of acetyl-subproside II methyl ester (5a) displayed an [MϪH] Ϫ ion at m/z 999.5160, which was consistent with the molecular formula as C 50 H 80 O 20 . Acid hydrolysis of 5a gave kudzusapogenol A 16) and L-arabinose, Lrhamnose, and D-glucuronic acid.…”

mentioning

confidence: 62%

Triterpenoid Saponins from the Roots of Sophora koreensis

Byun

Kim

Kang

et al. 2004

CHEMICAL & PHARMACEUTICAL BULLETIN

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Sophora koreensis NAKAI (syn. Echinosophora koreensisNAKAIϭKeyserlingia koreensis NAKAI) (Fabaceae) is a perennial nonclimbing shrub native to Korea.1) This plant bears characteristic four-winged fruit.2) There have been several reports on the isolation of flavonoids, 3-7) a coumarin, 5,8) alkaloids 6,9-12) sterols, 8) triterpenes, 11) and others 13) from the roots, flowers, and aerial parts of this plant. In a previous paper, 7) we reported on the isolation and structure elucidation of a saponin, kudzusaponin A 3 , 14,15) from this plant. Further study on this plant has yielded four known saponins, sophoraflavoside I (3), kudzusaponin SA 3 (4) subproside II (6), and azukisaponin V (7) and three new saponins, which we have called echinosophorosides A 1 (1) and B (2), and acetyl-subproside II (5). We report here the isolation and structure determination of these saponins.The dried and powdered roots of S. koreensis was extracted and partitioned as described in the Experimental section. Methylation of the n-butanol (BuOH) fraction with CH 2 N 2 , followed by successive chromatography using silica, Sephadex LH-20, and reverse-phase C 18 afforded compounds 1-7 as their methyl esters. The structures of these isolated compounds were established through analysis of their NMR and MS spectra, which enabled the characterization of compounds 1, 2, and 5 as novel and compounds 3, 4, 6, and 7 as known. Spectra for known saponins confirmed their structures to be sophoraflavoside I (3), kudzusaponin SA 3 (4), subproside II (6), and azukisaponin V (7).Echinosophoroside A 1 methyl ester (1a) was obtained as an amorphous powder. High-resolution (HR) FAB-MS gave the composition C 53 H 86 O 23 . An inspection of the 1 H-and 13 C-NMR spectra of the compound readily indicated the presence of four monosaccharide units through easily identifiable signals for anomeric protons and carbons. Acid hydrolysis of 1a afforded kudzusapogenol A (3b,21b,22b,24,29-pentahydroxyolean-12-ene) 16) as an aglycon and arabinose, rhamnose, and glucuronic acid as the sugar components identified on TLC analysis by comparison with authentic samples. Absolute configurations for sugars were determined to be the Lform except for glucuronic acid (D-form), according to the procedure developed by Hara et al.17) The negative-ion mode FAB mass spectrum of 1a exhibited an [MϪH] Ϫ ion at m/z 1089 which is consistent with a tetrasaccharide glycoside carrying two arabinose, one rhamnose, one glucuronic acid methyl ester, and an aglycon with a molecular mass of 490. Comparison of the 13 C-NMR data of the aglycon moiety of 1a with kudzusapogenol A 16) showed that the signals for C-3 and C-22 of 1a were significantly shifted downfield by ϩ11.3 and ϩ13.8 ppm, respectively, due to a glycosidation shift. 18)The 13 C-NMR spectrum of 1a was superimposable on that of kudzusaponin A 1 15) except for the xylopyranosyl signals at C-22 which were substituted for by the arabinopyranosyl moiety in 1a. From these observations, it was deduced that 1a was a 3,22-bisdesmoside of kudzu...

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“…The a-anomeric configurations of the L-arabinose was determined by its 3 J H1,H2 coupling constants (2.5 Hz) and J C1,H1 coupling constant (170 Hz). 4,9) The L-rhamnose was determined to have the a-configuration based on the broad singlet of its anomeric proton.…”

mentioning

confidence: 99%