SYNTHESIS AND BIOLOGICAL EVALUATION OF 2-(2'/3'/4'/6'-SUBSTITUTED PHENYL)-1H-INDOLES

Objective: Indole derivatives were reported to a wide range of biological activities. Thus it was our aim to synthesize a series of 2-(2'/3'/4'/6'-substituted phenyl) -1H-indoles using clayzic catalyst and screen for their in vitro anti-inflammatory, antioxidant and antimicrobial activities.Methods: Various substituted acetophenones were reacted with phenylhydrazine in the presence of modified clayzic catalyst and obtained 2-(2'/3'/4'/6'-substituted phenyl)-1H-indoles in a one pot reaction. The cyclized compounds were characterized by FT-IR, NMR, UV-Vis and mass spectral analyses and screened for anti-inflammatory activity against cytokines tumor necrosis factor (TNF-α) and interleukin-6 (IL-6) by measuring cytokine production by performing sandwich ELISA model, antioxidant activity by DPPH assay method and antimicrobial activity by well-diffusion method.Results: An eco-friendly route with better yields for the synthesis of 2-(2'/3'/4'/6'-substituted phenyl)-1H-indoles in the presence of clayzic catalyst was achieved. The biological activity results suggested that compounds (2d, 2e and 2i) have excellent anti-inflammatory activity, compounds (2a-2d and 2j) possessing better antioxidant property and compounds (2b, 2i, 2k and 2m) have promising antibacterial and antifungal activities when compared to the standard drugs.Conclusion: Synthesis of 2-(2'/3'/4'/6'-substituted phenyl)-1H-indoles was successfully achieved in the presence of clayzic catalyst. Compounds bearing amino, methyl, methoxy, hydroxyl and fluoro groups have shown better anti-inflammatory, antioxidant and antimicrobial activities when compared to the other compounds and 1H-indole.Â