Heptacoordinate Tin(IV) Compounds Derived from Pyridine Schiff Bases: Synthesis, Characterization, in Vitro Cytotoxicity, Anti-inflammatory and Antioxidant Activity

Abstract

Tin(IV) complexes 2a-q derived from pyridine Schiff bases were prepared and characterized. Four complexes of this series were evaluated in vitro against different carcinogenic cell lines; besides their anti-inflammatory and antioxidant properties were also tested. Combination of mass spectrometry, multinuclear NMR and Xray diffraction techniques evidenced the formation of heptacoordinated monomeric species. The X-ray diffraction analysis of 2a, 2b, 2i, 2j and 2n led to establish the heptacoordination around the tin atom in solid state and also revealed that the ligand occupies the equatorial positions of the distorted pentagonal bipyramidal geometry and the two alkyl or aryl groups the axial positions. The in-vitro study for complexes 2a-d against six tumor cell lines showed varied antiproliferative activity, the IC 50 for all tested complexes was lower than that of the cisplatin. Compounds 2a-d also exhibited anti-inflammatory activity where complex 2c resulted to be more active (IC 50 ‫11.0؍‬ m mM) than the indomethacin IC 50 ‫72.0؍‬ m mM which was used as reference. The antioxidant activity in rat brain homogenate on inhibition of thiobarbituric acid reactive substances (TBARS) indicated that 2c (IC 50 ‫77.1؍‬ m mM) is more active than the quercetine (4.11 m mM) and a a-tocopherol (IC 50 ‫90.965؍‬ m mM).

Anti-inflammatory, antioxidant and anti-acetylcholinesterase activities of Bouvardia ternifolia: potential implications in Alzheimer’s disease

“…Quercetin and a-Tocopherol compounds at 1 lg/ml were utilized as references and an inhibitor-free sample was employed as control. The antioxidant activity of the B. ternifolia extract and fractions was evaluated at 10 and 100 lg/ml as previously was shown (González et al 2009). As oxidative stress promoter, 10 lM of FeSO4 (Sigma) were added to each sample.…”

“…Increasing concentrations (10-1000 lg/ml) of BtHA, BtAcOEt, BtC1N, and Flav3 were employed in displacement curves of the lipid peroxidation assay. Quercetin and a-Tocopherol (0-100 lg/ml) were used as references (González et al 2009). The inhibition ratio (%) was calculated following the formula: Inhibition ratio (%) = (C -E)/ C 9 100 %, where C was the absorbance of control group and E, the absorbance of test group.…”

Synthesis, structural characterization and biological studies of the triphenyltin(IV) complex with 2-thiobarbituric acid

“…These complexes are prepared by refluxing a methanolic solution of the sodium salt of the ligands with organotin halides. 2-Thiobarbituric acid, on the other hand, is used as a scavenger of the radicals form from lipids peroxidation [16,17].…”

Synthetic, structural, and antimicrobial studies of organotin(IV) complexes of semicarbazone, thiosemicarbazone derived from 4-hydroxy-3-methoxybenzaldehyde

“…Thiosemicarbazones and semicarbazones are of great pharmacological interest since they show a board spectrum of biological activity including antitumor, antibacterial, antifungal, and anti-inflammatory activities [4][5][6][7][8][9][10]. Considering all of these, it is of important to synthesize vanillin thiosemicarbazone and semicarbazone with possible antimicrobial activities.…”