Novel carvacrol derivatives containing a thiosemicarbazide moiety: As potential antioxidants and α-glucosidase inhibitors

In this study, using the plant-derived active compound carvacrol as the lead structure, a series of carvacrol derivatives incorporating a thiosemicarbazide moiety were synthesized and their structures were characterized by 1H NMR,13C NMR, and HRMS. Subsequently, the in vitro antioxidant and α-glucosidase inhibitory activities of these compounds were evaluated. The bioassay results indicated that the target compounds exhibited certain in vitro antioxidant and α-glucosidase inhibitory activities. Among them, compound 2-(2-(5-isopropyl-2-methylphenoxy)acetyl)-N-phenylhydrazine-1-carbothioamide (4i) displayed the most potent in vitro antioxidant activity, with IC50 values of 4.98 μg/mL for DPPH scavenging activity and 2.34 μg/mL for ABTS scavenging activity, which were superior to those of vitamin C and trolox. Meanwhile, compound N-(4-fluorophenyl)-2-(2-(5-isopropyl-2-methylphenoxy)acetyl)hydrazine-1-carbothioamide (4j) exhibited excellent in vitro α-glucosidase inhibitory activity, with an IC50 value of 8.32 μg/mL, outperforming both carvacrol and acarbose.