Synthesis and radical scavenging activity of new phenolic hydrazone/hydrazide derivatives: Experimental and theoretical studies

•A series of new phenolic hydrazone/hydrazide derivatives has been synthesized.•The hydrazones are better radical scavengers than the hydrazone-hydrazide analogs.•The C = O group plays a negative role in the antiradical activity of hydrazide derivatives.•The NH group of the hydrazone is more reactive than that of the hydrazide and the OH groups.•Hydrazone (4) is a radical scavenger as potent as vitamin C and Trolox.