Preparation and structural studies on the tBu2Sn(IV) complexes with aromatic mono- and dicarboxylic acids containing hetero {N} donor atom

Synthesis biological screening and molecular docking studies of some tin (IV) Schiff base adducts

The search for an alternative to platinum anticancer agents is a major motivation for continuing investigations concerning the antitumor properties of other transition metal-based compounds. Keeping this in view, synthesis, antitumor and antimicrobial activity of diorganotin (IV) complexes was studied. A novel series of diorganotin (IV) complexes of the Schiff base ligand derived from 7-methoxy-2-hydroxy-1-naphthaldehyde, 1,2-phenylenediamine, Salicylaldehyde were synthesized. Physical and spectral examination was done through various techniques using elemental analyses, IR, ¹H, ¹³C, ¹¹⁹Sn NMR, and ^119mSn Mössbauer techniques respectively. The results obtained are in good agreement with 1:1:1 stoichiometry of Schiff base and 2:1 stoichiometry of the complexes. Octahedral geometry was assigned to all the synthesized complexes within six (6) coordination number around the tin. Antitumor activity was screened against human oral epidermoid carcinoma (KB) cell line. The diethyltin (IV) complex 2 showed the most promising cytotoxic results (IC₅₀=0.35μM) against the cell line which is comparable with cisplatin (IC₅₀=0.37μM). Docking studies revealed that these complexes can bind favorably within cisplatin binding site and the binding energy of complex 2 is more than that of cisplatin. Furthermore, binding of these complexes on human topoisomerase IIα enzyme and revealed that these complexes intercalating within the inter-strand of DNA showing interactions with DNA as well as protein that may results in DNA damage and cell death.

Synthesis and biological activity of organotin 4-methyl-1,2,3-thiadiazole-5-carboxylates and benzo[1,2,3]thiadiazole-7-carboxylates

A series of organotin 4-methyl-1,2,3-thiadiazole-5-carboxylates and benzo[1,2,3]thiadiazole-7-carboxylates have been synthesized and characterized by NMR ((1)H, (13)C, and (119)Sn), IR, and elemental analyses. The structure of the dimeric complex {[(BTHCO(2))SnEt(2)](2)O}(2) (BTH represents benzo[1,2,3]thiadiazol-7-yl) has been further confirmed by X-ray diffraction crystallography. Assessment for fungicidal activity indicates that all of the newly synthesized compounds exhibit good growth inhibition against Alternaria solani , Cercospora arachidicola , Gibberella zeae , Physalospora piricola , and Botrytis cinerea . High growth inhibition percentage at 50 microg/mL was obtained in vitro in the case of triorganotin 4-methyl-1,2,3-thiadiazole-5-carboxylates and benzo[1,2,3]thiadiazole-7-carboxylates. The corresponding EC(50) values of these triorganotin carboxylates have been detected, and values of EC(50) as low as 0.12 microg/mL against P. piricola and 0.16 microg/mL against G. zeae, respectively, were observed for triethyltin benzo[1,2,3]thiadiazole-7-carboxylate.