A study on the contents of allelochemical phenolic acids from different cultivars of alfalfa

The contents of five allelochemical phenolic acids(chlorogenic acid,p-coumaric acid,p-hydroxybenzoic acid,caffeic acid,and ferulic acid) from ten cultivars of alfalfa were analyzed by high performance liquid chromatography(HPLC).The allelochemical phenolic acids were aqueous extracts of aerial parts and roots and they differed between the alfalfa cultivars.The chlorogenic acid and caffeic acid contents of the extracts from the cultivar Alize were higher than those from other alfalfa cultivars.The chlorogenic acid contents of the extracts from aerial parts and roots of the cultivar Alize were 94.72 and 23.98 μg/g respectively and of caffeic acid were 30.49 and 6.3 3 μg/g respectively.The ferulic acid contents of extracts of aerial part and roots from the cultivar Alegro were 48.97 and 6.75 μg/g respectively,higher than those from other alfalfa cultivars.The p-hydroxybenzoic acid contents of the alfalfa extracts showed a highly significant positive correlation with the contents of caffeic acid,chlorogenic acid,and ferulic acid.The p-coumaric acid content of extracts from the aerial parts of alfalfa showed a highly significant positive correlation with the contents of caffeic acid and of ferulic acid,while the p-hydroxybenzoic acid content showed a highly significant positive correlation with the p-coumaric acid content.The caffeic acid content of the aqueous extracts of alfalfa roots showed a highly significant positive correlation with the chlorogenic acid and ferulic acid contents,and the chlorogenic acid content showed a highly significant positive correlation with the ferulic acid content.In addition,the phenolic acid content of the aqueous extracts of the same alfalfa cultivar differed between aerial parts and roots.