Using a bidentate ligand, a Schiff base of 5-acetamido-1,3,4- thiadiazole-2-sulphonamide, complexes of transition metals having the general formula ML2, where M = Mn(II), Fe(II), Ni(II) and Cu(II), were synthesized. The complexes were characterized by elemental analysis, molar conductivity, magnetic moment, electronic, ESR and IR spectroscopy, and particle size analysis. The conductivity data of the complexes suggests their non-electrolytic nature. The stability constants and free energy change for the complexes were calculated. Spectral studies and magnetic susceptibility measurements revealed an octahedral geometry for all the complexes. The ligand and its complexes were screened for their fungicidal activity against Aspergillus niger and A. flavus.

In this work, removal of fluorescein and eosin dyes using common agrowaste, i.e., peels of water melon (Citrullus lanatus) (WMP), has been studied in the batch mode. The sorbent material (WMP) was characterized by using scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and elemental analysis. The sorbent was chemically modified by subjecting it to 0.1 N HNO₃ and 0.1 N NaOH solutions. Different parameters such as sorbent dose, pH, temperature, and agitation speed were optimized to investigate the sorbent efficiency for fluorescein and eosin dyes. Among three forms (raw, base-treated, and acid-treated), the base-treated form exhibited higher removal efficiency, followed by acid-treated and then the raw form. Generally, range for the removal of fluorescein and eosin was found to be 48.06–88.08% and 48.47–79.31%, respectively. Mathematical modeling of sorption data by Langmuir and Freundlich sorption isotherms and thermodynamic investigations were carried out to check the suitability of these agrowaste materials on bulk scale. The promising results concluded that peel of water melon (common agrowaste) can be potentially utilized for the removal of toxins.

A new pyrimidine based Schiff base ligand (HL) and its four complexes of type [MLOAc]·nH₂O (Cu(II), 1; Zn(II), 2; Co(II), 3; and Ni(II), 4) have been synthesized and characterized by elemental analysis, MS, ¹H-NMR, FT-IR, UV-visible, and ESR techniques. The electronic and ESR spectral data suggested that complexes 1–4 possess square planar geometry. Antimicrobial activities of HL and complexes 1–4 were tested against four bacteria (Staphylococcus aureus, Staphylococcus pneumonia, Salmonella enterica typhi, and Haemophilus influenzae) and two fungal strains (Aspergillus flavus and Aspergillus niger). These results show that complexes 1–4 have good antimicrobial activity compared to HL. The DNA cleavage activity of HL and complexes 1–4 was monitored by the agarose gel electrophoresis method. The antioxidant property of the prepared compounds was assessed by using 2,2′-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. DNA binding properties of HL and complexes 1–4 have been investigated by electronic absorption technique and viscometric measurements.

In this research article, the synthesis, structural characterization, and biological, DNA binding and anticancer properties of pyrimidine incorporated Schiff base ligand L and its [CuL2](ClO4)2 (1) and [ZnL2](ClO4)2 (2) complexes are reported. The isolated complexes 1 and 2 have significant antibacterial and antifungal properties, greater than those of ligand L. The interaction between protein and L were analyzed by an in silico method. The intercalative binding of the prepared compounds was proved from electronic absorption, fluorometric, cyclic voltammetric and viscometric methods. The calculated binding parameters such as, Kb (2.65?103, L; 7.74?103, 1 and 2.99?103, 2); Ksv (3.30?103, L; 4.31?103, 1 and 3.89?103, 2), and Kapp (2.15?105, L; 3.30?105, 1 and 2.82?105, 2) indicted that complex 1 has better interaction ability than L and complex 2. The in vitro anticancer properties of L, and complexes 1 and 2 against human cancer (MCF-7, HeLa and HEp-2) and normal (NHDF) cell lines were determined by the MTT assay method. The obtained results designated that complexes 1 and 2 exhibited substantial anticancer activity against the cancer cell lines, better than that of L.

Isothermal study of Congo Red dye biosorptive removal from water by Solanum tuberosum and Pisum sativum peels in economical way

Two novel adsorbents Holarrhena antidysenterica (HA) and Citrullus colocynthis (CC) were collected from native Pakistan and treated with tartaric acid. The adsorbents were characterized by Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy, and their adsorptive behavior was studied against model cationic dye crystal violet (CV). Role of biosorbent dose, time of contact, temperature studies, agitation rates, and solution pH was investigated. Optimum conditions obtained for the removal of CV dye for H. antidysenterica-tartaric acid modified (HA-TA) were as follows: 0.8g adsorbent dose, 35 minutes contact time, 5.0 pH, 40°C temperature, and 150rpm agitation rates as compared to H. antidysenterica that gave 1.4g adsorbent dose, 40 minutes time of contact, 6.0 pH, 50°C temperature, and 150rpm agitation speed. C. colocynthis-tartaric acid modified (CC-TA) removed CV dye at 0.6g adsorbent dose, 30 minutes contact interval, 4.0 pH, 40°C temperature, and 125rpm agitation speed in contrast to C. colocynthis which gave 0.8g adsorbent dose, 40 minutes time of contact, 6.0 pH, 50°C temperature, and 125rpm agitation speed, respectively. Isothermal studies for both raw and modified biosorbents were compliant with the Langmuir model indicating monolayer, chemisorption. The maximum Langmuir capacities were up to 128.20mg/g, 136.98mg/g, 144.92mg/g, and 166.66mg/g for HA, CC, HA-TA, and CC-TA. Pseudo-second-order kinetic model well fitted the dye removal data. The rate-determining steps involved both surface and intraparticle diffusion mechanisms. Adsorption of dye molecules on active surfaces was governed by electrostatic attractions and chelating abilities. Thermodynamics research revealed the spontaneous and exothermic nature of the reaction. The adsorbents serve promising candidates for the effective removal of hazardous dyes from aqueous solutions.