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Kaempferol Glycosides (kaempferol + glycoside)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Two New Kaempferol Glycosides from Androsace umbellata

HELVETICA CHIMICA ACTA, Issue 7 2009
Jun Lei
Abstract Two new kaempferol glycosides, 5-hydroxy-2-(4-hydroxyphenyl)-4-oxo-7-(, - L -rhamnopyranosyloxy)-4H -chromen-3-yl 2- O -acetyl-3- O - , - D -glucopyranosyl- , - L -rhamnopyranoside (1) and 5-hydroxy-2-(4-hydroxyphenyl)-4-oxo-7-(, - L -rhamnopyranosyloxy)-4H -chromen-3-yl , - D -glucopyranosyl-(1,2)-6- O -[(2E)-3-(4-hydroxyphenyl)prop-2-enoyl]- , - D -glucopyranosyl-(1,2)- , - D -glucopyranoside (2), along with ten known compounds, were isolated from the 95% EtOH extract of the whole plant of Androsace umbellata. The structures of the new glycosides were determined on the basis of detailed spectroscopic analyses, including 1D- and 2D-NMR, MS, and chemical methods. [source]

Kaempferol Glycosides from Lobularia maritima and Their Potential Role in Plant Interactions

CHEMISTRY & BIODIVERSITY, Issue 2 2009
Antonio Fiorentino
Abstract Six kaempferol glycosides, four of them characterized for the first time, were isolated from the leaf extract of Lobularia maritima. The structural elucidation was performed by a combined approach using Electrospray-Ionization Triple-Quadrupole Mass-Spectrometric (ESI/TQ/MS) techniques, and 1D- and 2D-NMR experiments (1H, 13C, DEPT, DQ-COSY, TOCSY, ROESY, NOESY, HSQC, HMBC, and HSQC-TOCSY). The isolated kaempferol derivatives have different disaccharide substituents at C(3) and four of them have a rhamnose unit at C(7). To evaluate their potential allelopathic role within the herbaceous plant community, the compounds, as well as the aglycone obtained from enzymatic hydrolysis, have been tested in vitro on three coexisting plant species, Dactylis hispanica, Petrorhagia velutina, and Phleum subulatum. The results obtained allow us to hypothesize that the type of the sugar modulates the biological response. The bioassay data, analyzed by a multivariate approach, and grouping the compounds on the basis of the number of sugar units and the nature of carbohydrates present in the disaccharide moiety, indicate a structure,activity relationship. [source]

Two New Kaempferol Glycosides from Androsace umbellata

HELVETICA CHIMICA ACTA, Issue 7 2009
Jun Lei
Abstract Two new kaempferol glycosides, 5-hydroxy-2-(4-hydroxyphenyl)-4-oxo-7-(, - L -rhamnopyranosyloxy)-4H -chromen-3-yl 2- O -acetyl-3- O - , - D -glucopyranosyl- , - L -rhamnopyranoside (1) and 5-hydroxy-2-(4-hydroxyphenyl)-4-oxo-7-(, - L -rhamnopyranosyloxy)-4H -chromen-3-yl , - D -glucopyranosyl-(1,2)-6- O -[(2E)-3-(4-hydroxyphenyl)prop-2-enoyl]- , - D -glucopyranosyl-(1,2)- , - D -glucopyranoside (2), along with ten known compounds, were isolated from the 95% EtOH extract of the whole plant of Androsace umbellata. The structures of the new glycosides were determined on the basis of detailed spectroscopic analyses, including 1D- and 2D-NMR, MS, and chemical methods. [source]

Kaempferol Glycosides from Lobularia maritima and Their Potential Role in Plant Interactions

CHEMISTRY & BIODIVERSITY, Issue 2 2009
Antonio Fiorentino
Abstract Six kaempferol glycosides, four of them characterized for the first time, were isolated from the leaf extract of Lobularia maritima. The structural elucidation was performed by a combined approach using Electrospray-Ionization Triple-Quadrupole Mass-Spectrometric (ESI/TQ/MS) techniques, and 1D- and 2D-NMR experiments (1H, 13C, DEPT, DQ-COSY, TOCSY, ROESY, NOESY, HSQC, HMBC, and HSQC-TOCSY). The isolated kaempferol derivatives have different disaccharide substituents at C(3) and four of them have a rhamnose unit at C(7). To evaluate their potential allelopathic role within the herbaceous plant community, the compounds, as well as the aglycone obtained from enzymatic hydrolysis, have been tested in vitro on three coexisting plant species, Dactylis hispanica, Petrorhagia velutina, and Phleum subulatum. The results obtained allow us to hypothesize that the type of the sugar modulates the biological response. The bioassay data, analyzed by a multivariate approach, and grouping the compounds on the basis of the number of sugar units and the nature of carbohydrates present in the disaccharide moiety, indicate a structure,activity relationship. [source]