Phenolic Acids

Abstract

To idenrify the major phenolic acids responsible for their antioxidative activities, four kinds of Korean soybeans (yellow, brown, black and small black Soybeans) were extracted with n-hexane, dicholoromethane, ethyl acetate, n-butanol and water sequentially. The highest antioxidative activity of soybeans was found in ethyl acetate fraction. The phenolic acids identified by TLC, HPLC and UV spectra in ethyl acetate fraction were p-coumaric, p-hydroxy benzoic, trans-cinnamic, syringic, ferulic and salicylic acids, Antioxidative activities of 0.05% standard phenolic acids were compared and chlorogenic, p-hydroxy benzoic, trans-cinnamic acid were turned out to have strong antioxidative activities. When we compared the antioxidative effect of phenolic acids in soybean itself, antioxidative activities wire highest in the following order, syringic, ferulic, p-hydroxy benzoic, trans-cinnamic and p-coumaric acid. Interestingly, syringic acid contained in small amount in soybean showed quite strong antioxidative effect.