Alkyl esters of hydroxycinnamic acids with improved antioxidant activity and lipophilicity protect PC12 cells against oxidative stress

► Methyl, ethyl, propyl and butyl esters of caffeic and ferulic acids were tested. ► Caffeate esters were stronger antioxidants and more lipophilic than parent compound. ► Ferulate esters were weaker antioxidants, but more lipophilic than parent compound. ► Caffeate esters inhibited oxidative stress-induced PC12 neuronal cell death. ► Antioxidant capacity and lipophilicity are both important for neuroprotection.