Distribution and physiological functions of caffeoylquinic acid derivatives in leaves of sweetpotato genotypes

Six caffeoylquinic acid derivatives of sweetpotato leaves, Ipomoea batatas (L.) Lam. were identified and quantified using 1389 genotypes collected worldwide. These were divided into 3 categories based on the leaf polyphenol. content: high, medium, and low polyphenol accumulator. RP-HPLC analysis was used to quantify caffeic acid, chlorogenic acid (3-o-caffeoylquinic acid), 3,4-di-o-caffeoylquinic acid, 3,5-di-o-caffeoylquinic acid, 4,5-di-o-caffeoylquinic acid and 3,4,5-tri-o-caffeoylquinic acid. The caffeic acid and derivatives were positively correlated with the total polyphenol contents, and the correlation coefficients varied widely among the different categories. The caffeoylquinic acid derivatives showed higher DPPH-radical scavenging activity (%), and higher antimutagenicity by showing effectively inhibiting the reverse mutation induced by Trp-P-1 on Salmonella typhimurium TA 98.