Saima Gul

Novel synthesis of silver nanoparticles using melon aqueous extract and evaluation of their feeding deterrent activity against housefly Musca domestica

Objective To synthesize silver nanoparticles (AgNPs) adopting a green approach and evaluate their toxicological potential against housefly Musca domestica which is responsible for spreading a number of fatal diseases.

In vitro anti-leishmanial and anti-fungal effects of new SbIII carboxylates

Ring opening of phthalic anhydride has been carried out in acetic acid with glycine, β-alanine, L-phenylalanine, and 4-aminobenzoic acid to yield, respectively, 2-{[(carboxymethyl)amino]carbonyl}benzoic acid (I), 2-{[(2-carboxyethyl)amino]carbonyl}benzoic acid (II), 2-{[(1-carboxy-2-phenylethyl)amino]carbonyl}benzoic acid (III), and 2-[(4-carboxyanilino)carbonyl]benzoic acid (IV). Compounds I-IV have been employed as ligands for Sb(III) center (complexes V-VIII) in aqueous medium. FTIR and 1H NMR spectra proved the deprotonation of carboxylic protons and coordination of imine group and thereby tridentate behaviour of the ligands as chelates. Elemental, MS, and TGA analytic data confirmed the structural hypothesis based on spectroscopic results. All the compounds have been assayed in vitro for anti-leishmanial and anti-fungal activities against five leishmanial strains L. major (JISH118), L. major (MHOM/PK/88/DESTO), L. tropica (K27), L. infantum (LEM3437), L. mex mex (LV4), and L. donovani (H43); and Aspergillus Flavus, Aspergillus Fumigants, Aspergillus Niger, and Fusarium Solani. Compound VII exhibited good anti-leishmanial as well as anti-fungal impacts comparable to reference drugs.

Organotin(IV) esters of 4-maleimido-benzoic acid: synthesis, characterization and in vitro anti-leishmanial effects

Six new diorganotin(IV) esters with the general composition R2SnL2 (where R: Me(1), Et(2), Pr(3), Bu(4), Ph(5), Bz(6) and L(7): p-N-maleimido-benzoic acid) have been synthesized. Solid state FTIR and 119mSn Mossbauer spectra revealed bidentate behavior of L towards the diorganotin(IV) centre in the distorted octahedral products. 1H, 13C and 119Sn NMR spectra in CDCl3 indicated hexacoordination in 1-4, penta-coordination of 5 in skew-trapezoidal geometry, and absence of hypercoordination in tetrahedral 6. Elemental analyses data have been found to corroborate the stoichiometry of the title organotin(IV) compounds. In vitro anti-leishmanial screenings have been conducted on five leishmanial strains of L. major, L. tropica, L. infantum, L. mex. mex. and L. donovani. Promising results have been observed and, on the basis of the data obtained during these assays, a structure-activity relationship has been suggested. The increasing size of the R groups in the {R2SnIV}2+ moieties increased the lipophilicity of organotin(IV) complexes, which thereby enhanced the anti-leishmanial activity.

Green synthesis of zerovalent copper nanoparticles for efficient reduction of toxic azo dyes congo red and methyl orange

Abstract In this study, plant-mediated copper nanoparticles (CuNPs) were synthesized. Due to its direct synthesis mechanism and eco-friendly nature, the current method accounts for the green chemistry approach using the fruit extract of Duranta erecta for the first time. The UV-visible spectrum of the CuNPs solution showed a distinct absorption peak at 588 nm. Fourier transform infrared spectroscopy confirmed that the fruit extract is responsible for the reduction as well as the stabilization of CuNPs. X-ray diffraction patterns conform the crystalline nature of CuNPs. Energy-dispersive X-ray spectroscopy was performed for elemental analysis whereas field emission scanning electron microscopy was carried out for surface morphology. Prepared CuNPs were used for the reduction of carcinogenic azo dyes methyl orange (MO) and congo red (CR). CuNPs exhibit outstanding catalytic reduction for MO and CR in the presence of NaBH4 as reducing agents with the pseudo-first-order rate constants of 8.6×10−3 s−1 and 5.07×10−3 s−1 for MO and CR, respectively. Thus, natural plant materials act as cheap and environmentally friendly support for the synthesis of CuNPs and could be used for the purification of water from organic dye effluents.

Medicago polymorpha-mediated antibacterial silver nanoparticles in the reduction of methyl orange

Abstract The aim of the presented work was to assess the potential of Medicago polymorpha extract to synthesize silver nanoparticles (AgNPs) as a green method. It was a simple one-step synthesis approach and the product obtained was characterized by UV-visible spectroscopy, Fourier transform infrared (FTIR), powder X-ray diffraction, thermogravimetric analysis, and field-emission scanning electron microscopy (FE-SEM). At room temperature, the optimum time for the completion of the reaction (i.e. the formation colloidal solution) was just 5 min. FE-SEM images showed that AgNPs were predominantly in spheres, whereas FTIR spectrum analysis inferred that gallic acid present in the extract initially reduced silver ions to elemental silver. The carboxylic and hydroxyl groups of biomolecules present in the extract stabilized AgNPs by passivating the surface to prevent aggregation, resulting in uniform distribution. The antibacterial activity of synthesized AgNPs showed effective inhibitory effects against waterborne pathogens, including Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), at a minimum inhibitory concentration of 10 μg/ml. Membrane permeability and respiration studies were also performed to assess the surface role of the synthesized AgNPs. The prepared AgNPs exhibited excellent antioxidant activity and catalytic reduction of methyl orange with a rate constant of 6.8×10−3 s−1.