木虫 (文坛精英)
假装忧伤的枯木桩 ![]()
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happykeren2008(金币+1000, 翻译EPI+1):谢谢 2010-10-10 20:46:36
Compound 1
Compound 1, white powered, melting point 246~248℃, which exhibits positive in Libermann-Burchard reaction and red in Ehrlish reaction was supposed to be furostanol saponins. Detection of D-glucose and D-galactose with acid hydrolysis and D-glucose with emulsin enzymolysis indicates that D-galactose was connected to the aglycone. ESI-MS manifests molecularion peak at 920.
For 1H-NMR test (C5D5N, δ, ppm), anomeric proton signal of carbohydrate are 5.28(1H, d, J=7Hz), 4.91(1H, d, J=8Hz) and 4.80(1H, d, J=8Hz), while coupling constant values of compound 1 indicates the β-configuration of all anomeric carbons. 1.32(3H, d), 1.03(3H, d), 0.98(3H, s) and 0.88(3H, s) are four methyl hydrogen signals.
For 13C-NMR test (C5D5N, δ, ppm), δ105.7, 104.8, 102.2 and 110.4 are anomeric carbons signals of carbohydrate and 110.4 represents C-1. Excluding carbon from carbohydrate in upfield region, there are four CH3，twelve CH2，seven CH and three quaternary carbons. Aglycone of compound 1 contains twenty-seven carbons.
In accordance with chemical shift and type of carbons in the aglycone, it is suspected that the structure of aglycone is 25(s)-22-hydroxy-5β furostanol-3β, 26-glycol. Based upon the analysis listed above, carbohydrate connected to C3 of aglycone is β-D-glucopyranosyl(1→2)-β-D-galactopyranose and C26 of aglycone is β-D-glucopyranose.
Compound 2
Compound 2, which is buff acicular crystal, exhibits dirty green in reaction with FeCl3 and almon pink in HCL-Mg reaction. ESI-MS manifests molecularion peak at m/z445 [M+Na]+, 423[M+1]+ indicates molecular mass of compound 6 is 422.
For 1H-NMR test (DMSO-d6, δ), 4.61(1H, d, J=9.8Hz) represents one glucose anomeric proton which exists as β-glucoside bond. In addition, 6.39(1H, s), 6.88(1H, s) and 7.40(1H, s) are three aromatic protons.
For 13C-NMR and DEPT (DMSO-d6, δ) test, 179.1 is carbonyl signal in downfield region and twelve signals of 163.6, 161.4, 156.3, 153.8, 150.8, 143.6, 111.8, 108.1, 107.5, 102.6, 101.3, and 93.4 indicate the compound includes two benzene rings. 81.5, 78.8, 73.1, 70.5, 70.2 and 61.4 represents a hexose signal in upfield region. |
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