[Synthesis and characterization of protocatechuic acid derivants].

To explore the effects of protocatechuic acid (PCA) and its derivants on angiogenesis of the chick embryo chorioallantoic membrane (CAM) and scavenging DPPH radical in vitro. The protection of benzyl and alkaline hydrolysis of benzyl ester were employed. The structures of PCA-1, PCA-2 and PCA-3, the derivates of PCA, were elucidated by 1H, 13C-NMR and MS data The bioactivity of PCA and its derivants was evaluated on the models of DPPH radical and chick embryo chorioallantoic membrane (CAM), respectively. PCA and PCA-1 showed the best activity of scavenging DPPH radical among all the compounds. In contrast to PCA-2, PCA and PCA-3 displayed inhibition to angiogenesis (P < 0.001). Pyrocatechol hydroxyl is the active site of PCA on scavenging DPPH radical in vitro. PCA with carboxyl and without pyrocatechol hydroxyl seems to show promotion to angiogenesis, but it needs more evidences.