Antioxidative activities of caffeoyl-proline dipeptides

► Twenty caffeoyl-proline dipeptides CA-Pro-Xaa-NH2 were synthesised. ► Antioxidant activity was measured by DPPH
- scavenging and lipid peroxidation tests. ► CA-Pro-His-NH2 suppressed lipid peroxidation most efficiently. ► CA-Pro-His-NH2 mainly exists as cis proline conformer. ► This explains the exceptionally enhanced antioxidant activity of CA-Pro-His-NH2.