Mukhtiar Hussain

Synthesis, Chemical Characterization and Biological Screening for Cytotoxicity and Antitumor Activity of Organotin (IV) Derivatives of 3,4-Methylenedioxy 6-nitrophenylpropenoic Acid

A series of mono-, di- and triorganotin compounds with general formulae [RSnL(2)Cl], R = Bu (compound 3), [R(2)SnL(2)], where R = Me, Et, Bu, Oct (compounds 1, 2, 4 and 6) and [R(3)SnL], where R = Bu, Cy and Ph (compounds 5, 7 and 8) and where L = 3,4-methylenedioxy-6-nitrophenylpropenoic acid have been prepared and characterized by elemental analysis, multinuclear ((1)H-, (13)C- and (119)Sn-) NMR and mass spectrometry. The ligand and its respective organotin complexes were screened for cytotoxicity using the brine shrimp lethality assay and for antitumor activity using the crown gall tumor inhibition (potato disc) assay. The bioassay results support the conclusion that the biological activities of these synthetic compounds are in the following order: [RSnL(2)Cl] < [R(2)SnL(2)] < [R(3)SnL].

Di‐ and Triorganotin(IV) Esters of 3,4‐Methylenedioxyphenylpropenoic Acid: Synthesis, Spectroscopic Characterization and Biological Screening for Antimicrobial, Cytotoxic and Antitumor Activities

Nine biologically significant organotin(IV) esters of 3,4‐Methylenedioxyphenylpropenoic acid (L) were synthesized with the general formulae [R2SnL2], where R includes Me(1), Et(3), But(4), Oct(5), Ph(8), and [R3SnL], in which R is Me(2), Cy(6), Ph(7), and But(9). The acid and its compounds were characterized by basic analytical techniques comprising elemental analysis, FTIR and mass spectrometry in solid state and by Multinuclear (1H, 13C and 119Sn) NMR in solution form, which provides some important information about the different coordination behaviors of metal in both solid and solution. Methylenedioxy moiety in these compounds enhances the biological activity of these compounds. These compounds were screened for a range of biological activities. Antibacterial activities were determined against six pathogenic bacterial strains, three gram‐positive and three gram‐negative, the activities were measured in terms of inhibition zones (mm). Results demonstrate that diorganotin derivatives are more active than triorganotin derivatives and ligand acid. Antifungal activity was determined against six pathogenic fungal strains, cytotoxicity by the brine shrimp lethality assay, and antitumor activity by crown gall tumor inhibition (potato disc) assay. Results for antifungal activity, cytotoxicity, and antitumor activity of these compounds demonstrate that triorganotin derivatives are more active than diorganotin derivatives and ligand. Finally, the results were compared with similar reports in the literature.

ATR-FTIR spectroscopy detects alterations induced by organotin(IV) carboxylates in MCF-7 cells at sub-cytotoxic/-genotoxic concentrations

The environmental impact of metal complexes such as organotin(IV) compounds is of increasing concern. Genotoxic effects of organotin(IV) compounds (0.01 μg/ml, 0.1 μg/ml or 1.0 μg/ml) were measured using the alkaline single-cell gel electrophoresis (comet) assay to measure DNA single-strand breaks (SSBs) and the cytokinesis-block micronucleus (CBMN) assay to determine micronucleus formation. Biochemical-cell signatures were also ascertained using attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy. In the comet assay, organotin(IV) carboxylates induced significantly-elevated levels of DNA SSBs. Elevated micronucleus-forming activities were also observed. Following interrogation using ATR-FTIR spectroscopy, infrared spectra in the biomolecular range (900 cm-1 – 1800 cm-1) derived from organotin-treated MCF-7 cells exhibited clear alterations in their biochemical-cell fingerprint compared to control-cell populations following exposures as low as 0.0001 μg/ml. Mono-, di- or tri-organotin(IV) carboxylates (0.1 μg/ml, 1.0 μg/ml or 10.0 μg/ml) were markedly cytotoxic as determined by the clonogenic assay following treatment of MCF-7 cells with ≥ 1.0 μg/ml. Our results demonstrate that ATR-FTIR spectroscopy can be applied to detect molecular alterations induced by organotin(IV) compounds at sub-cytotoxic and sub-genotoxic concentrations. This biophysical approach points to a novel means of assessing risk associated with environmental contaminants. PACS codes: 87.15.-v, 87.17.-d, 87.18.-h

Structural and biological studies of new monomeric, tetrameric, and polymeric organotin(IV) esters of 3-(benzo[d][1,3]dioxol-4-yl)propanoic acid

Six new monomeric, tetrameric, and polymeric organotin(IV) derivatives of sodium 3-(benzo[d][1,3]dioxol-4-yl)propanoate (NaL) have been synthesized and characterized by various analytical techniques. These compounds show different structural behavior in solution and solid state as confirmed by NMR and X-ray single-crystal analysis. Antimicrobial and antitumor activities are mainly governed by diffusion, lipophilicity, geometry, and steric factors. The high antitumor and antifungal activities of some of these organotin compounds demand further investigations to commercialize them as new tin-based drugs.

Synthesis and coordination chemistry of organotin(IV) complexes of 2,3-methylenedioxyphenylpropenoic acid

The synthesis, spectroscopy, and antitumor behavior of organotin(IV) complexes of 2,3-methylenedioxyphenylpropenoic acid are described. The spectroscopic data indicate 1 : 2 and 1 : 1 metal to ligand stoichiometry in case of di- and trioganotin(IV) compounds and hypervalency of Sn(IV) in trigonal bipyramidal and octahedral modes. Mass spectrometric and elemental analysis data support the solid and solution spectroscopic results. The complexes have been evaluated in vitro against crown gall tumor and bio-activity screenings showed in vitro biological potential. The nature of covalent attachments (methyl, ethyl, n-butyl, phenyl, and n-octyl) of Sn(IV) played a decisive role for bioactivity. All the compounds have been studied in solution by NMR (1H, 13C) and also in solid state using FTIR, mass spectrometry, and by X-ray crystallography. The molecular structure of Et2Sn(IV) and Me3Sn(IV) derivatives confirm the behavior of di- and tri-organotin(IV) compounds in solid state. Mono-organotin derivatives are octahedral both in solid and solution.

High efficiency ZnO nano sensor, fabrication and characterization

Ultra fine thin films of pure and SnO doped ZnO nanosensor were grown on gold digitated ceramic substrate from bis(2, 4- pentanedionate)dimethylethanolamine zinc (II) using bis(2, 4-pentanedionate) tin(II) chloride as a dopant by ultrasonic aerosol assisted chemical vapor deposition technique (UAACVD) at temperature range of 400–450 °C under oxygen atmosphere at 5 Pa pressure. The sensitivity, selectivity, fast recovery, and reliability test performed on nanosensor suggested that both doped and undoped ZnO thin films are suitable for detecting ethanol vapor in the temperature range of at 60 to 150 °C, whereas at room temperature (25 °C) response and recovery time of the sensor increases many folds compared to 60 °C. Sensitivity of the ZnO sensor shows linear relationship with the increase of gas concentration. Electrical properties show that 1 % SnO doped ZnO enhanced the sensitivity of the film drastically and thus improved its detecting efficiency. Physico-chemical techniques like, CHNS-O, atomic absorption analyzer, and infra red and multinuclear nuclear magnetic resonance spectrometers were used for precursor characterization. X-ray diffractometer, scanning electron microscope, sigma scan analyzer and energy dispersive x-ray techniques were used for thin film characterization.

Dimethyltin(IV) Derivatives of Biologically Potent Substituted Phenylacrylic Acids: Synthesis, Chemical Characterization and Inhibitory Effects on Agrobacterium tumefaciens

Effect of dimethyltin(IV) complexes of different substituted phenyl acrylic acids on the ability of Agrobacterium tumefaciens to cause tumours in plants was studied by using potato discs. The results demonstrated significant inhibition of tumours formation. All the compounds were synthesized and characterized by using analytical techniques, i.e. FTIR, multinuclear NMR (1H, 13C, 19F and 119Sn) and mass spectrometry. These studies explain that dimethyltin(IV) derivatives exist in a deformed octahedral environment known as skew trapezoidal geometry with four strong and two weaker bonds.

Fluoro Substituted Monomeric and Uni-Dimensional Polymeric Organotin(IV) Esters of (E)-4-oxo-4-((3-trifluoromethyl)phenyl)amino)but-2-enoic acid; Synthesis, Characterization and Their In vitro Inhibitory Studies

Inhibition effects of novel organotin(IV) esters of (E)-4-oxo-4-((3-trifluoromethyl)phenyl)amino)but-2-enoic acid have been studied against bacterial, fungal, tumoral and insecticidal strains. The complexes have shown potency against all these strains and is attributed to the multiple interactive sites of the ligand that not only change the environment around tin but also can make interactions with DNA. The synthesized complexes were characterized by physical, spectral, analytical and multinuclear nmr (1H, 13C, 119Sn) data. The X-ray structure analysis of the complex is reported.

Structure elucidation and inhibitory effects of self-assembled organotin(IV) esters of p-tolyl acetic acid on bacterial, fungal, brine shrimp, and potato tumor cells

Biologically active new organotin(IV) acetates (1–6) of p-tolyl acetic acid have been synthesized and characterized by multinuclear nuclear magnetic resonance (1H, 13C) and mass spectrometry. The X-ray crystallographic data of compounds (3 and 4) were also collected. These studies show that in diorganotin(IV) compounds (compounds 1, 2, 3, and 6), tin exists in skew trapezoidal geometry with four strong and two weaker bonds, whereas triorganotin(IV) carboxylates (compounds 4 and 5) have four and five coordinated geometries in solution and solid form, respectively. These compounds were screened for a range of biological activities. Antibacterial activities were determined against six pathogenic bacterial strains, three Gram-positive and three Gram-negative; the activities were measured in terms of inhibition zones (mm). Antifungal activities were determined against six pathogenic fungal strains, cytotoxicity by the brine shrimp lethality assay, and antitumor activities by the crown gall tumor inhibition (potato disc) assay.

In vitro Antitumor and Antibacterial Assay of Organotin(IV) Complexes of 2,3- Methylenedioxybenzoic Acid; X-Ray Crystal Structure of ((C2H5)2Sn(C8H5O4)2)

New organotin(IV) compounds containing the carboxylate ligand 2,3-methylenedioxybenzoic acid (HL) have been synthesized with the general formula R2SnL2 (R = Me, Et, n-Bu, Ph and n-Oct) and R3SnL (R = n-Bu). All compounds have been studied in the solution state by multinuclear NMR (1H, 13C and 119Sn) by using the non-coordinating solvent and also in solid sate by FTIR, mass spectrometry and X-ray crystallography. Spectroscopic data have shown that methylenedioxy moiety does not coordinate with tin atom and the coordination site is actually -COO group, as is proved by X-ray structure determination. The solid state structure of compound (2) has been determined by X-ray crystallography which shows that the complex (2) has distorted octahedral geometry. These complexes have been evaluated in vitro against crown gall tumor and antibacterial activity. Interesting results were noticed during the bio-activity screenings, which proved their in vitro biological potential and possible use as drugs.