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Publikacije (28)

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Selma Fetahović, M. Fočak, A. Višnjevac, S. Roca, V. Muzika, D. Žilić, Lucija Vujević, Sabina Žero et al.

Five neutral heteroleptic mononuclear vanadium(IV) hydrazone complexes ([VOL(bpy)]), derived from 2-hydroxy-5-methylacetophenone and various acid hydrazides (furoic, thiophene, benzoic, nicotinic, and isoniazid), were synthesized and shown to exhibit improved antidiabetic efficacy in streptozotocin-induced diabetic rats, with reduced toxicity and minimal bioaccumulation compared to maltolato- and picolinato-based vanadium species. Structural identity was established by spectroscopic methods. Crystal structures were obtained for four complexes, providing insight into their solid-state chemistry. Stability studies in simulated intestinal and gastric fluids showed that the complexes largely retained their integrity under intestinal conditions, whereas decomposition occurred in the highly acidic gastric environment within several minutes. In vivo experiments revealed a structure-antihyperglycemic activity relationship. The nicotinic-containing complex showed the highest activity, reducing blood glucose levels by 67% within 7 days of treatment, while the remaining complexes improved glycemic control by more than 50%. Bioaccumulation studies demonstrated <1.1% uptake in the liver and kidneys and negligible accumulation in the brain. The presented vanadium compounds enhance antidiabetic potential by addressing key limitations, particularly bioaccumulation and toxicity, associated with vanadium agents previously evaluated in clinical trials.

<p>Three new neutral complexes of copper(II) containing chalcone ligands derived from 2'-hydoxyacetophenone and 4-substituted benzaldehydes were synthesized. Complexes were prepared by solution synthesis and characterized by spectroscopy. The catalytic activity of complexes was examined in the reaction of 3,5-di-tertbutylcatehcol (DTBC) oxidation. The kinetics of DTBC catalytic oxidation by copper(II) complexes (1 &ndash; 3) was investigated spectrophotometrically under pseudo-first-order conditions. Catalytic parameters, the maximum reaction rate (vmax), Michaelis-Menten constant (KM), catalytic efficiency, catalytic reaction rate constant (kcat), turnover number (TON), and turnover frequencies (TOF) for complexes 1 &ndash; 3 in DTBC oxidation were collected. The studied complexes 1 and 2 were found to have moderate catalytic activity, while complex 3 does not show catalytic properties.</p>

The issue of water contamination by heavy metal ions as highly persistent pollutants with harmful influence primarily on biological systems, even in trace levels, has become a great environmental concern globally. Therefore, there is a need for the use of highly sensitive techniques or preconcentration methods for the removal of heavy metal ions at trace levels. Thus, this research investigates a novel approach by examining the possibility of using pomegranate (Punica granatum) peel layered material for the simultaneous preconcentration of seven heavy metal ions; Cd(II), Co(II), Cr(III), Cu(II), Mn(II), Ni(II) and Pb(II) from aqueous solution and three river water samples. The quantification of the heavy metals was performed by the means of FAAS technique. The characterization of biomaterial was performed by SEM/EDS, FTIR analysis and pHpzc determination before and after the remediation process. The reusability study, as well as the influence of interfering ions (Ca, K, Mg, Na and Zn) were evaluated. The conditions of preconcentration by the column method included the optimization of solution pH (5); flow rate (1.5 mL/min), a dose of biosorbent (200 mg), type of the eluent (1 mol/L HNO3), sample volume (100 mL) and sorbent fraction (<0.25 mm). The biosorbent capacity ranged from 4.45 to 57.70 μmol/g for the investigated heavy metals. The practical relevance of this study is further extended by novel data regarding adsorbent cost analysis (17.49 $/mol). The Punica granatum sorbent represents a highly effective and economical biosorbent for the preconcentration of heavy metal ions for possible application in industrial sectors.

A. Zahirović, Selma Hadžalić, A. Višnjevac, M. Fočak, B. Tüzün, D. Žilić, S. Roca, J. Jurec et al.

Solution synthesis afforded five novel neutral heteroleptic octahedral paramagnetic mononuclear oxidovanadium(IV) complexes of general composition [VO(bpy)L], where L is a dianionic tridentate ONO-donor hydrazone ligand derived from 2-furoic acid hydrazide and salicylaldehyde and its 5-substituted derivatives. Characterization was carried out by elemental analysis, mass spectrometry, infrared, electron, NMR, and EPR spectroscopy, cyclic voltammetry and conductometry. The molecular and crystal structure of the complex with 5-chloro-salicylaldehyde 2-furoic acid hydrazone (2) was determined. The quantum chemical properties of the vanadium complexes were studied at B3LYP and M062X levels with the lanl2dz basis set using Gaussian. Additionally, Swiss-ADME analysis was performed and complex (4), featuring a 5-nitro substituent on the hydrazone ligand, was selected for further investigation. The effects of the in vivo application of the complex on selected biochemical parameters in healthy and diabetic Wistar rats were investigated. Strong antidiabetic effect associated with moderate hypoalbuminemia was observed. Furthermore, the interaction of complexes with BSA was studied by spectrofluorimetry. A significant conformational change of BSA in the presence of vanadium complexes was found. Synchronous fluorescence spectra revealed significant changes in the tyrosine microenvironment of BSA. The FRET analysis was also used and the non-radiative process of energy transfer is elucidated. Thermodynamic data suggest van der Waals forces and hydrogen bonding as predominant binding modes of complexes to BSA.

A. Zahirović, Irnesa Osmanković, A. Osmanović, A. Višnjevac, Amina Magoda, Selma Hadžalić, E. Kahrović

Two copper(II) complexes of 4-chloro- and 4-dimethylaminobenzaldehyde nicotinic acid hydrazones were prepared and characterized by elemental analysis, mass spectrometry, infrared and electron spectroscopy and conductometry. These rare examples of bis(hydrazonato)copper(II) complexes are neutral complex species with copper(II) center coordinated with two monoanionic bidentate O,N-donor hydrazone ligands coordinated in enol-imine form. The interaction of hydrazone ligands and corresponding copper(II) complexes with CT DNA and BSA was investigated. Copper(II) complexes are slightly effective in binding the DNA than pristine hydrazones. The results indicate groove binding or moderate intercalation which are not significantly affected by the nature of substituent at hydrazone ligands. On contrary, affinities of two copper(II) complexes toward BSA significantly differs and depends on the nature of the substituent, however in absence of thermodynamic data difference in nature of binding forces cannot be excluded. The complex bearing electron-withdrawing 4-chloro substituent has larger affinity toward BSA compared to 4-dimethyamino analogue. These findings were theoretically supported by molecular docking study.

: Complexes of general formula [ Ru(bpy) 2 (L) ]CF 3 SO 3 , where bpy = 2,2′ - bipyridine, and L = Schiff bases derived from salicylaldehyde and amino acids (glycine ( 1a), cysteine (1b), methionine (1c ) and phenylalanine ( 1d )) were synthesized. Characterization based on elemental analysis, Ru content, mass, infrared and electronic spectra confirmed RuN 5 O coordination unlike 1b where coordination occurred via azomethine nitrogen and cysteine sulfur. Cyclic voltammograms, except 1b, showed several quasi- reversible redox pairs in the positive potential range, the first located at about 0.5 V, corresponding to similar heteroleptic Ru(II) bipyridyl complexes. Biological activity was tested by interactions with DNA and BSA. DNA binding constants of order 10 3 M − 1 , suggest groove binding due to bpy ligand and hydrogen bonding of the OH and CO groups from the imine moiety. In vitro BSA protein inhibition assay performed by spectrofluorimetry showed Complex : BSA binding in 1 : 1 ratio with K b of 10 4 M − 1 order. Cytotoxicity studies by MTT assay for 72 h of drug action revealed activity of 1a and 1d against breast cancer MCF- 7 cells with IC 50 values 32 ± 8 and 26 ± 1µM, respectively.

E. Kahrović, V. Jakovljevic, A. Zahirović

Studies of materials used for works of art and cultural monuments throughout the history contribute to the comprehensive understanding of particular cultures, their technological achievements and customs over time. Investigations of the authenticity of objects and the interventions they may have endured over time keep an important role for their successful restoration and preservation. A three-layer sample of the colored wall decoration from Ottoman Ćejvan Ćehaja mosque from Mostar, Bosnia and Herzegovina was investigated by FTIR spectroscopy. The plaster was identified as gypsum-lime binder. Inorganic pigments were found in two layers, reddish-brown mixture of Fe2O3 and MnO2 and green pigment recognized as viridian, Cr2O3 ∙ 2H2O. The upper layer of "golden color" is found to be a physically compact piece of gold foil or leaf whose fixation method meets both the Ottoman and "west" mode of binding. The mode of adhesion by animal glue could be the result of decoration immanent to Islamic culture, but also to reconstruction from the late 19th century during the Austro-Hungarian rule in Bosnia.

A. Zahirović, D. Žilić, S. K. Pavelić, M. Hukić, Senada Muratović, A. Harej, E. Kahrović

Synthesis, characterization and interaction with BSA and apo-transferrin of novel water-soluble ruthenium complexes having differently coordinated alliin (S-allyl-l-cysteine sulfoxide).

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