Affiliation: | aCentro de Estudos Farmacêuticos, Faculdade de Farmácia, Universidade de Coimbra, 3000-295 Coimbra, Portugal bLaboratório de Farmacognosia, Faculdade de Farmácia, Universidade de Coimbra, 3000-295 Coimbra, Portugal cUnidad de Nutrición y Bromatología, Facultad de Farmacia, Universidad de Salamanca, 37007 Salamanca, Spain dDepartamento de Ambiente, Instituto Politécnico de Viseu, Campus Politécnico de Repeses, 3504-510 Viseu, Portugal |
Abstract: | Leaves from cultivated Cymbopogon citratus were extracted with methanol, 80% aqueous ethanol and water (infusion and decoction) and the extracts were assessed for their antiradical capacity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay; the infusion extract exhibited the strongest activity. Tannins, phenolic acids (caffeic and p-coumaric acid derivatives) and flavone glycosides (apigenin and luteolin derivatives) were identified in three different fractions obtained from an essential oil-free infusion, and a correlation with their scavenger capacity for reactive oxygen species was studied. The tannin and flavonoid fractions were the most active against species involved in oxidative damage processes. In the flavonoid fraction, representing 6.1% of the extract, thirteen compounds (O- and C-glycosylflavones) were tentatively identified by high performance liquid chromatography, coupled to photodiode-array and electrospray ionization mass spectrometry detectors (HPLC–PDA–ESI/MS), nine of which were identified for the first time in this plant, all of them being C-glycosylflavones (mono-C-, di-C- and O,C-diglycosylflavones). The potential beneficial and protective value of the identified polyphenols for human health is discussed. |