Synthesis of coumarin derivatives containing pyrazole and indenone rings as potent antioxidant and antihyperglycemic agents

Abstract

The present work describes the synthesis of 6-substituted-3-(1-(4-substituted)-4-((Z)-(5,6-dimethoxy-1-oxo-1H-inden-2(3H)-ylidene)methyl)-1H-pyrazol-3-yl)-2H-chromen-2-one derivatives (5a–l) by Claisen–Schmidt condensation of 3-(6-substituted-2-oxo-2H-chromen-3-yl)-1-(4-substituted)-1H-pyrazole-4-carbaldehyde derivatives (4a–l) with 5,6-dimethoxy-2,3-dihydro-1H-inden-1-one at reflux temperature for 8 h. The synthesized compounds were screened for in vitro antioxidant activity. Compounds 5e and 5g showed promising DPPH radical scavenging activity with IC50 54.14–56.19 μg/mL, ferrous ion chelating ability with IC50 53.75–56.89 μg/mL and reductive capability with IC50 58.01–62.57 μg/mL. The selected compounds were also tested for in vivo antihyperglycemic activity against Streptozotocin–nicotinamide induced Adult Wistar rats. Compounds 5e and 5g showed significant decrease in glucose concentration (115 and 138 mg/dL) with the dose of 100 mg/kg.

Keywords

• Coumarin
• Pyrazole
• Indenone
• Antioxidant
• Antihyperglycemic
• Streptozotocin–nicotinamide