Hydroxycinnamic acid clustered by a calixarene platform: radical scavenging and antioxidant activity

Novel hydroxycinnamic acid-calix[4]arene hybrids 4 and 5 were synthesized. Their radical scavenging and antioxidant activities were determined by using DPPH radical and AIBN-induced linoleic acid peroxidation test, respectively. Preliminary studies showed that compounds 4 and 5 possess enhanced activity with respect to the corresponding hydroxycinnamic acid and phenetidine derivative. Kinetic solvent effects were taken in account to understand the different antioxidative behaviour of the synthesized compounds.