New pentacoordinated diorganotin(IV) complexes of o-aminophenol based Schiff base ligands: Synthesis, characterization, antioxidant, antimicrobial and molecular docking studies

In the present study, sixteen new diorganotin(IV) complexes of the general formula R2SnL1-4 where, R = methyl, ethyl, butyl phenyl and -L-1 = 4-chloro-2-(((2-hydroxy-5-(tert-pentyl)phenyl)imino)methyl)phenol; L-2 = 3-ethoxy-2-(((2-hydroxy-5-(tert-pentyl)phenyl)imino)methyl)phenol; L-3 = 4-bromo-2-(((2-hydroxy-5-(tert-pentyl)phenyl)imino)methyl)phenol; L-4 = 4-nitro-2-(((2-hydroxy-5-(tert-pentyl)phenyl)imino) methyl)phenol) were synthesized and characterized by elemental analysis, molar conductance measurements, FT-IR, mass spectrometry, NMR (H-1, C-13, and Sn-119), powder XRD, TGA, SEM and EDAX. Spectroscopic data elucidated that Schiff base ligands coordinate to the tin metal via ONO donor atoms in a tridentate manner. The synthesized compounds were explored for their antioxidant potential by performing DPPH assay and the data obtained demonstrated that complex 12 (IC50 = 2.57 mu M) showed good antioxidant potential. The prepared compounds were also assessed for antimicrobial potential against bacterial and fungal strains and especially complex 20 being most effective against Escherichia coli (MIC = 0.0026 mu mol/mL) and Candida albicans (MIC = 0.0052 mu mol/mL). Further, molecular docking studies of the most potent complex 20 was performed to investigate the preferred binding modes in the active site of enzymes E. coli DNA Gyrase and C. albicans sterol 14-alpha demethylase. Additionally, in silico studies were conducted to assess the drug-like properties of the compounds (1-20), and the results indicated that the compounds have the potential to be utilized as orally active drugs. [GRAPHICS]