Xanthene derivatives are an important class of heterocyclic compounds with a wide spectrum of pharmacological activities. In our previous investigations, we found the good antiproliferative activity of two xanthene derivatives, with minimal toxicity investigated by in vitro tests. In this study, we tested the interaction of compound 1 (powerful potent antiproliferative compound) with calf thymus DNA (CT-DNA) under physiological conditions by spectrophotometric titration. The probable prediction of binding and the type of interaction forces involved in the arrangement between xanthene derivatives and CT-DNA were explored also through molecular docking studies. The results indicated that compound 1 interacts with CT-DNA by grove binding. The binding constant was found to be 2.5 ∙ 10 4 M −1 indicating the non-covalent binding of compound 1 to CT-DNA. Docking study results proposed possible binding modes, with binding energies of −9.39 and −8.65 kcal mol −1 for compounds 1 and 2, respectively, which supported previously obtained in vitro results for antiproliferative activity. In addition to experimental investigation, density functional theory (DFT) calculation with B3LYP/6-31G*, B3LYP/6-31G**, and B3LYP/6-31+G* levels of theories was performed on compounds 1 and 2 to obtain optimised geometry, spectroscopic and electronic properties. These studies could help in understanding the mechanisms of toxicity, resistance, side effects of xanthene derivatives, and their binding action mechanism to DNA

This work aimed to describe the synthesis and characterisation of two anionic Ru(III) complexes of the general formula Na[Ru - Cl 2 ( N -4-Cl-Ph-salim) 2 ] and Na[RuCl 2 ( N -3-Br-Ph-salim) 2 , their associated ligands, and determine their antioxidant activity. The ligands N- 4-Cl-phenylsalicylidenimine ( N -4-Cl-Ph-salimH, HL a ) and N- 3-Br-phenylsalicylidenimine ( N -3-Br-Ph-salimH, HL b ), Schiff bases, were synthesised from salicylaldehyde and chloroaniline or bromoaniline. The compounds were characterised us - ing IR spectroscopy and ESI ToF mass spectrometry. The following was confirmed: coordination of ligands on the Ru(III) centre, the molecular formulas, and the corresponding M − ions: [C 26 H 18 N 2 O 2 Cl 4 Ru] − ion, (m/z: 631.9173) and [C 26 H 18 N 2 O 2 Cl 2 Br 2 Ru] − ion, (m/z: 719.8283). The antioxidant activity was determined by the ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays. In contrast to the ligands, both complexes proved to be strong scaven - gers of the ABTS and DPPH radicals with IC 50 (half maximal inhibitory concentration) values comparable to those of Trolox. As such, they present valuable candidates for further research related to their biological properties.

Various toxic heavy metals have become hazardous to human health as well as the environment. This research has been focused on a biosorption/bio-removal process of chromium (III), copper (II) and lead (II) ions from an aqueous solution by utilizing lignocellulosic biomass of Citrus limon peel (CLP) powder. CLP powder biomass was selected based on dietary fibre components having greater potential to remove target heavy metal ions in order to purify wastewater by following the eco-friendly biosorption method. At optimum conditions, the observed maximum removal efficiency of 97.47, 87.13 and 95.71% for Cr, Cu and Pb ions, respectively, was observed. An investigation has been made as a work of pH, CLP amount and temperature. The presented bio-removal processes by prepared CLP biosorbent manifested as a temperature-independent. Langmuir isotherm model was found an excellent fit of the isotherm data for tested systems with the calculated biosorption capacities of 111.11 (Cr), 76.92 (Cu) and 100.00 (Pb) mg/g. The positive ΔH values for selected target heavy metal ions, except lead ions, confirmed that the reaction was spontaneous and endothermic. A cooperative mechanism of second-order and intraparticle diffusion models during the adsorption processes of all three target ions was established with a higher coefficient of determination and more closely anticipated take-up (adsorption capacity). Furthermore, the interaction of -OH and -COOH functional groups of CLP that have a major role in the removal of Cr, Cu and Pb ions from single-ion aqueous solution and/or a surface biosorption was confirmed based on the results presented by SEM-EDS and FTIR analysis. Analysis from XRD revealed peak corresponding to amorphous cellulose type I as observed by FT-IR analysis.

Two tetraketone derivatives, one previously reported and one novel, were synthesized, whose structures have been confirmed by elemental analyses, NMR, HPLC-MS, and IR spectroscopy. The crystal structures of synthesized tetraketones were determined using X-ray single-crystal diffraction. To analyze the molecular geometry and compare with experimentally obtained X-ray crystal data of synthesized compounds 1 (2,2'-((4-nitrophenyl)methylene)bis(5,5-dimethylcyclohexane-1,3-dione)) and 2 (2,2'-((4-hydroxy-3-methoxy-5-nitrophenyl)methylene)bis(5,5-dimethylcyclohexane-1,3-dione)), DFT calculations were performed with the standard 6-31G*(d), 6-31G**, and 6-31+G* basis sets. The calculated HOMO-LUMO energy gap for compound 1 was 4.60 eV and this value indicated that compound 1 is chemically more stable compared to compound 2 whose energy gap was 3.73 eV. Both compounds' calculated bond lengths and bond angles were in very good accordance to experimental values determined by X-ray single-crystal diffraction.

This article reports on an investigation into the ability of SiO2–Ta2O5 as a new sorbent for simultaneous preconcentration of Cd(ii), Co(ii), Cr(iii), Cu(ii), Fe(iii), Mn(ii), Ni(ii) and Pb(ii) ions from water by the column method and the parameters involved in this process.

This article reports on an investigation into the ability of SiO2–Ta2O5 as a new sorbent for simultaneous preconcentration of Cd(ii), Co(ii), Cr(iii), Cu(ii), Fe(iii), Mn(ii), Ni(ii) and Pb(ii) ions from water by the column method and the parameters involved in this process.