Abstract
Cinnamic and hydoxycinnamic acid esters (alpha, beta-unsaturated esters), functional derivatives of cinnamic acids (cinnamic, ferulic, sinapic, caffeic) are secondary plant methabolites derived from phenylpropanoid pathway. Cinnamates, of both natural and synthetic origin, continue to elicit great interest due to diversity of biological activities they possess, such as: antioxidant, antimicrobial, anticancer, anti-inflammatory, anti-tyrosinase and etc.
Herein, the reduction of N alpha- and side chain protected amino acids to N-protected amino alcohols and the coupling of the latest with hydroxycinnamic (sinapic and ferulic) acids is described. 1,1-Diphenyl-2-picrylhydrazyl (DPPH radical) scavenging activities of hydroxycinnamates were compared with their corresponding N-hydroxycinnamoyl amino acid amides. Free hydroxycinnamic acids were used as positive controls.
The results indicated that N-hydroxycinnamoyl amino acid amides exhibited lower scavenging ability than the corresponding free hydroxycinnamic acids, but higher one than hydroxycinnamates.