Synthesis of protocatechuic acid grafted chitosan copolymer: Structure characterization and in vitro neuroprotective potential

•Antioxidant protocatechuic acid-g-chitosan (PCA-g-CS) copolymer was prepared via free radical-induced grafting reaction firstly.•The copolymer had the ability to scavenge free radicals in vitro.•The neuroprotective effect of the copolymer against H2O2 and GLU-induced apoptosis neuron-like cells was evaluated.