A new flavonol glycoside, 5,7,3,4 tetrahydroxy 3 methoxyflavonol 3 O β D glucopyranoside(1) was isolated along with quercetin(2), quercetin 3 O α L rhamnopyranoside(3), quercetin 3 O β D ...A new flavonol glycoside, 5,7,3,4 tetrahydroxy 3 methoxyflavonol 3 O β D glucopyranoside(1) was isolated along with quercetin(2), quercetin 3 O α L rhamnopyranoside(3), quercetin 3 O β D glucopyranoside(4) and kaempferol 3 O β D (6' O p coumaroyl) glucopyranoside(5) from Anaphalis sinica Hance. Their structures were determined on the basis of spectral data(MS, UV, IR, 1H and 13 C NMR). The structure of compound 1 was confirmed by X ray crystallographic analysis.展开更多
Six ent-kaurene type diterpenoids have been isolated from the leaves of Rabdosia nervosa. Among them, ganervosin A and B were new compounds, the structures of which were elucidated as 1 and 2 respectively by spectral ...Six ent-kaurene type diterpenoids have been isolated from the leaves of Rabdosia nervosa. Among them, ganervosin A and B were new compounds, the structures of which were elucidated as 1 and 2 respectively by spectral and chemical methods. The other four were identified as odonicin (3), novelrabdosin (4), nodosin (5) and shikokianal acetate (6), Compounds 5 and 6 were for the first time isolated from this herb.展开更多
Fast atom bombardment mass spectrometry (FAB-MS) is applied to distinguish N- terminal series ions from C-terminal series ions of a peptide by on-probe acetylation, it provides valuable information about the sequence ...Fast atom bombardment mass spectrometry (FAB-MS) is applied to distinguish N- terminal series ions from C-terminal series ions of a peptide by on-probe acetylation, it provides valuable information about the sequence of an unknown peptide. The FAB mass spectra contain a number of characteristic ions at low-mass region in addition to the sequence ions at high-mass region. It was found that the ions below m/z 200 are characteristic of the amino acid composition of the peptide, from which the amino acid composition of the peptide could be estimated. Additionally, mixture analysis is also discussed.展开更多
文摘A new flavonol glycoside, 5,7,3,4 tetrahydroxy 3 methoxyflavonol 3 O β D glucopyranoside(1) was isolated along with quercetin(2), quercetin 3 O α L rhamnopyranoside(3), quercetin 3 O β D glucopyranoside(4) and kaempferol 3 O β D (6' O p coumaroyl) glucopyranoside(5) from Anaphalis sinica Hance. Their structures were determined on the basis of spectral data(MS, UV, IR, 1H and 13 C NMR). The structure of compound 1 was confirmed by X ray crystallographic analysis.
文摘Six ent-kaurene type diterpenoids have been isolated from the leaves of Rabdosia nervosa. Among them, ganervosin A and B were new compounds, the structures of which were elucidated as 1 and 2 respectively by spectral and chemical methods. The other four were identified as odonicin (3), novelrabdosin (4), nodosin (5) and shikokianal acetate (6), Compounds 5 and 6 were for the first time isolated from this herb.
文摘Fast atom bombardment mass spectrometry (FAB-MS) is applied to distinguish N- terminal series ions from C-terminal series ions of a peptide by on-probe acetylation, it provides valuable information about the sequence of an unknown peptide. The FAB mass spectra contain a number of characteristic ions at low-mass region in addition to the sequence ions at high-mass region. It was found that the ions below m/z 200 are characteristic of the amino acid composition of the peptide, from which the amino acid composition of the peptide could be estimated. Additionally, mixture analysis is also discussed.
