Bioactive constituents of germinated fenugreek seeds with strong antioxidant potential

Germinated fenugreek seeds rich in bioactive antioxidant substances are used extensively as an important ingredient in daily food preparations and herbal formulations. The present study was carried out to isolate and identify active antioxidant principles from germinated fenugreek seeds. The partitioned extracts, column fractions and sub-fractions of germinated fenugreek seeds were subjected to activity assessment using standard in vitro antioxidant assays. Compounds with high antioxidant activity were identified by UV scan, mass analysis, NMR and LC-MS/MS. Bioactivity guided fractionation of the ethyl acetate extract led to isolation of vitexin (1) and isovitexin (2) as the major antioxidant compounds. These compounds were found to exert their effect at various levels of antioxidant action. LC-MS/MS analysis of ethyl acetate extract showed pre-dominance of apigenin, kaempferol and caffeic acid derivatives which may also additionally contribute to the observed antioxidant activity. This is the first report describing the phytochemical composition of germinated fenugreek seeds.