Synthesis of phthalide derivatives and evaluation on their antiplatelet aggregation and antioxidant activities.

As part of our continuing efforts to discover structurally interesting bioactive phthalide derivatives, 23 of them with a structure incorporating thiophen or halogens were designed and synthesized, 17 of which are previously unreported. In vitro antiplatelet aggregation activity screening showed that 14b could significantly inhibit platelet aggregation induced by arachidonic acid, compared with edaravone (p < 0.01). Meanwhile, oxidative damage models using SH-SY5Y and PC12 cells induced by H₂O₂ were built to evaluate the antioxidant activity of the phthalide derivatives. In SH-SY5Y cells, compared with aspirin, 1a significantly increased the relative cell survival rate (p < 0.05). Compared with edaravone, 1a (p < 0.01) and 15b (p < 0.05) significantly increased the relative cell survival rate. In PC12 cells, 1a (p < 0.01), 15b (p < 0.01), and 12a (p < 0.05) remarkably increased the cell survival rate compared with edaravone. The present study identified lead structures to develop potential anti-ischemic stroke agents.