Antioxidant activities of thiosemicarbazones from substituted benzaldehydes and N-(tetra-O-acetyl-β-d-galactopyranosyl)thiosemicarbazide

Reaction of N-(2,3,4,6-tetra-O-acetyl-β-d-galactopyranosyl)thiosemicarbazide and different substituted benzaldehydes gave some new substituted benzaldehyde N-(2,3,4,6-tetra-O-acetyl-β-d-galactopyranosyl)thiosemicarbazones. The reaction was performed using conventional and microwave-assisted heating methods. The structures of thiosemicarbazones were confirmed by spectroscopic (IR, 1H NMR, 13C NMR and ESI-MS) method. The antioxidant activity of these thiosemicarbazones was evaluated in vitro and in vivo, and it's shown that some of these compounds had significant antioxidant activity. Amongst the compounds screened for antioxidant activity, thiosemicarbazones 4a, 4b and 4c showed good antioxidant activity on DPPH. The compounds 4g, 4i, 4l caused significant elevation of SOD activity and 4e, 4g, 4i, 4l had higher catalase activity, and only compounds 4c and 4f expressed the GSH-Px activity.

Graphical abstractSome new substituted benzaldehyde (2,3,4,6-tetra-O-acetyl-β-d-galactopyranosyl)thiosemicarbazones were synthesized. The antioxidant activity of these thiosemicarbazones was evaluated in vitro and in vivo, and it's shown that some of these compounds had significant antioxidant activity.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► New substituted benzaldehyde (tetra-O-acetyl-β-d-galactopyranosyl)thiosemicarbazones. ► The in vitro and in vivo antioxidant activity on DPPH, SOD, catalase and GSH-Px. ► Compounds 4a, 4b and 4c showed good antioxidant activity on DPPH. ► Compounds 4g, 4i, 4l caused significant elevation of SOD and catalase activities.