title: Flavan hetero-dimers in the Cymbopogon citratus infusion tannin fraction and their contribution to the antioxidant activity.
abstract: Cymbopogon citratus (lemongrass) leaf infusion, a commonly used ingredient in Asian, African and Latin American cuisines, is also used in traditional medicine for the treatment of several pathological conditions; however, little is known about their bioactive compounds. Recent studies revealed the crucial role of the phenolic compounds namely flavonoids and tannins on the infusion bioactivity. Flavonoids have already been characterized; however the tannin fraction of lemongrass infusion is still uncharted. The aim of the present work is to characterize this fraction, and to evaluate its contribution to the antioxidant potential of this plant. Chemical characterization was achieved by HPLC-DAD-ESI/tandem MS and the antioxidant activity was evaluated using DPPH, ABTS and FRAP assays. Hetero-dimeric flavan structures have been described for the first time in lemongrass consisting of apigeniflavan or luteoliflavan units linked to a flavanone, either naringenin or eriodictyol, which may occur as aglycone or glycosylated forms. The antioxidant capacity of the fraction containing these compounds was significantly higher than the infusion, indicating its potential as a source of natural antioxidants.
authors: Centre for Pharmaceutical Studies, School of Pharmacy, University of Coimbra, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal. mtpmb@ff.uc.pt.
authors: Gustavo
authors: G
authors: Costa
authors: Susana
authors: S
authors: González-Manzano
authors: Ana
authors: A
authors: González-Paramás
authors: Isabel Vitória
authors: IV
authors: Figueiredo
authors: Celestino
authors: C
authors: Santos-Buelga
authors: Maria Teresa
authors: MT
authors: Batista
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D047310:Apigenin / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D031743:Cymbopogon / Q000737:chemistry*; D020834:Ethnopharmacology; D044950:Flavanones / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D005419:Flavonoids / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D006027:Glycosides / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D047311:Luteolin / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D008519:Medicine, Traditional; D015394:Molecular Structure; D008970:Molecular Weight; D018515:Plant Leaves / Q000737:chemistry*; D011174:Portugal; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D013634:Tannins / Q000032:analysis / Q000302:isolation & purification; D000069459:Teas, Herbal / Q000032:analysis*
chemical_list: D000975:Antioxidants; D044950:Flavanones; D005419:Flavonoids; D006027:Glycosides; D013634:Tannins; D000069459:Teas, Herbal; D047310:Apigenin; C005273:naringenin; D047311:Luteolin; C007619:eriodictyol