Antioxidant compounds from the fresh pericarp of Vicia faba L. cultivar rena mora cultivated in Egypt

DPPH screening of both seed and pericarp extracts of Vicia faba L. cv. Rena Mora in fresh and dried form revealed that the 70% alcoholic extract of fresh pericarp showed maximum antioxidant activity. It was then fractionated using different organic solvents. The antioxidant activity of the different fractions was determined by DPPH method. The IC₅₀ were calculated, using ascorbic acid standard. Ethyl acetate "VE", n- butanol "VB" and aqueous "VQ" fractions showed the highest activity with IC₅₀ values of 29.25, 149.35 and 22.47µg/ml respectively. Chromatographic fractionation of fraction "VE" led to isolation of quercetin-7- O-α-L-rhamnopyranoside, kaempferol-7- O-α-L-rhamnopyranoside and kaempferol-3-O-(6''-O-acetyl)- β- D-galactopyranoside-7- O-α-L-rhamnopyranoside, while chromatographic fractionation of fraction "VB" led to the isolation of asparagine, L-DOPA and tyrosine. The chemical structures of the isolated compounds were established by UV, HRESI-MS, 1D and 2D NMR experiments. HPLC/amino acid analysis of fraction "VQ" revealed presence of sixteen amino acids; aspartic acid, threonine, serine, glutamic acid, glycine, alanine, cystine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, histidine, lysine and arginine.