title: Flavonoids in Leguminosae: analysis of extracts of T. pratense L., T. dubium L., T. repens L., and L. corniculatus L. leaves using liquid chromatography with UV, mass spectrometric and fluorescence detection.
abstract: Reversed-phase LC on C-18 bonded silica with a methanol-ammonium formate gradient was used to determine the main flavonoids in leaves of four species of the Leguminosae family. The detection modes were diode-array UV absorbance, fluorescence, and (tandem) mass spectrometry. LC-UV was used for a general screening, sub-classification, and the calculation of total flavonoid contents. LC-FLU was included to identify isoflavones on the basis of their native fluorescence. Most structural information regarding aglycons, sugar moieties, and acidic groups was derived from LC-MS in both the full-scan and extracted-ion mode, using negative-ion atmospheric pressure chemical ionization. MS/MS did not provide much additional information, because the same fragments were observed as in full-scan MS. In T. pratense and T. repens, the main constituents were flavonoid glucoside-(di)malonates, while T. dubium and L. corniculatus mainly contained flavonoid (di)glycosides. Satellite sets comprising an aglycon, the glucoside and glucoside-malonates or -acetates, were abundantly present only in T. pratense. Generally speaking, the main aglycons and sugars in the four plant species are surprisingly different. In addition, while the results for T. pratense are similar to those reported in the literature, there is little agreement in the case of the other species. Finally, total flavonoid contents ranged from 50-65 mg/g for L. corniculatus and T. dubium, to 15 mg/g for T. pratense and only 1 mg/g for T. repens.
authors.affiliation: Department of Analytical Chemistry and Applied Spectroscopy, Free University, de Boelelaan 1083, 1081 HV Amsterdam, The Netherlands. drijke@few.vu.nl
authors.forename: Eva
authors.initials: E
authors.lastname: de Rijke
authors.forename: Herman
authors.initials: H
authors.lastname: Zappey
authors.forename: Freek
authors.initials: F
authors.lastname: Ariese
authors.forename: Cees
authors.initials: C
authors.lastname: Gooijer
authors.forename: Udo A T
authors.initials: UA
authors.lastname: Brinkman
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D007887:Fabaceae / Q000737:chemistry*; D005419:Flavonoids / Q000032:analysis* / Q000737:chemistry*; D005453:Fluorescence; D013058:Mass Spectrometry / Q000379:methods; D015394:Molecular Structure; D010936:Plant Extracts / Q000032:analysis* / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D005419:Flavonoids; D010936:Plant Extracts