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).
View Article and Find Full Text PDFAlkali metal cation adducts, [M+Alk](+), and [M-H](-) ions of four known glycosylated furofuran lignans, (+)-pinoresinol 4-O-beta-D-glucopyranoside, (+)-phylliroside, (+)-8-hydroxypinoresinol 4-O-beta-D-glucopyranoside, and (+)-8-hydroxypinoresinol 8-O-beta-D-glucopyranoside, recently isolated from Carex distachya, were generated by electrospray ionization and allowed to undergo collisionally activated dissociation (CAD) in a quadrupole ion trap (QIT) and in a triple quadrupole (TQ) mass spectrometer. CAD mass spectra of [M+Na](+) and [M+Li](+) adducts revealed the presence of structurally diagnostic product ions. CAD mass spectra of deprotonated glycosylated furofuran lignans showed the typical neutral loss of 162 Da when the glucose residue was bound to a phenolic oxygen atom.
View Article and Find Full Text PDFIn the present study, the chemical composition and antioxidant properties of root methanol extract of Carex distachya Desf. (Cyperaceae) were assessed to use this plant as sources of food additives and nutraceuticals. The IC50 of the extract (4.
View Article and Find Full Text PDFOne new and six known flavone glycosides were isolated from the MeOH extract of Melilotus neapolitana Ten. The new compound, identified as 7-O-beta-D-glucopyranosyloxy-4',5-dihydroxy-3-[O-alpha-L-rhamnopyranosyl-(1-->6)-3-O-beta-D-glucopyranosyloxy]flavone (1) by 1D and 2D NMR techniques and mass spectra, was isolated along with kaempferol-3-O-rutinoside (2), kaempferol-3-O-glucoside (3), rutin (4), quercetin-3-O-glucoside (5), isorhamnetin-3-O-rutinoside (6), and isorhamnetin-3-O-glucoside (7). The antioxidant and radical scavenging activities of these compounds and the whole crude methanol extract were evaluated.
View Article and Find Full Text PDFSeven cinnamic acid amides have been isolated from Chenopodium album. The structures have been attributed by means of their spectral data. One of them, N-trans-4-O-methylferuloyl 4'-O-methyldopamine, is described for the first time.
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