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Ajla Alijagic, E. Kahrović, Saida Ibragić

This paper describes the combined use of several analytical methods to characterise the painting technology used in two socialist realism portraits of national heroes from World War II that are now housed in the Historical Museum of Bosnia and Herzegovina. Inspection under UV light has shown that there was no previous retouching or overpainting on either painting. Microchemical tests identified the type of canvas. The radiograms indicated whether pigments with lower or higher atomic masses were used and how well the ground was rubbed among the threads of the canvas. A better penetration of the ground into the canvas and layers of oil dye that were applied to both sides of Painting 1 contributed to its better protection against high humidity. TLC revealed the type of ground on both paintings as a classic chalk-glue ground. The high humidity was responsible for the occurrence of metal soaps on Painting 2, which were confirmed by FTIR. The XRF analysis was used to describe the pigment palette, trace the causes of existing damages, and facilitate retouching. The results of this integrated diagnostic approach were used to optimise the conservation and better understand the features and techniques used in the creation of Bosnian socialistic artwork.

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, Anja 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).

OBJECTIVES Dinuclear ruthenium(II) Schiff base complex was selected for in vivo study among many other novel metal-based compounds, because of its previously proved in vitro anticancer and antibacterial properties. The aim was to investigate the potential toxicity of this compound in animal model through biochemical and histopathological assessment. METHODS Adult Swiss albino mice of both sexes were divided into high-dose and low-dose group that received a single intraperitoneal dose of ruthenium complex (175 mg/kg and 25 mg/kg, respectively) and one control group (vehicle only). After a follow-up period of 14 days, animals were sacrificed to obtain blood samples and organs. RESULTS The test compound was well tolerated in a low-dose group and did not cause any mortality. The histological findings and serum biochemistry suggested a reversible character of alterations found in vital organs of this group. However, in the high-dose group, adverse effects were more severe and indicated dose and gender-related toxicity. CONCLUSION Mild side effects found in a low-dose group together with excellent in vitro properties, made dinuclear ruthenium(II) Schiff base complex a promising candidate for further investigation and development as anticancer and antimicrobial agent (Tab. 4, Fig. 6, Ref. 32).

U. Glamočlija, S. Padhye, S. Špirtović-Halilović, A. Osmanović, E. Veljović, S. Roca, I. Novaković, B. Mandic et al.

Thymoquinone (TQ), a natural compound with antimicrobial and antitumor activity, was used as the starting molecule for the preparation of 3-aminothymoquinone (ATQ) from which ten novel benzoxazole derivatives were prepared and characterized by elemental analysis, IR spectroscopy, mass spectrometry and NMR (1H, 13C) spectroscopy in solution. The crystal structure of 4-methyl-2-phenyl-7-isopropyl-1,3-benzoxazole-5-ol (1a) has been determined by X-ray diffraction. All compounds were tested for their antibacterial, antifungal and antitumor activities. TQ and ATQ showed better antibacterial activity against tested Gram-positive and Gram-negative bacterial strains than benzoxazoles. ATQ had the most potent antifungal effect against Candida albicans, Saccharomyces cerevisiae and Aspergillus brasiliensis. Three benzoxazole derivatives and ATQ showed the highest antitumor activities. The most potent was 2-(4-fluorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazole-5-ol (1f). Western blot analyses have shown that this compound inhibited phosphorylation of protein kinase B (Akt) and Insulin-like Growth Factor-1 Receptor (IGF1R β) in HeLa and HepG2 cells. The least toxic compound against normal fibroblast cells, which maintains similar antitumor activities as TQ, was 2-(4-chlorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazole-5-ol (1e). Docking studies indicated that 1e and 1f have significant effects against selected receptors playing important roles in tumour survival.

Spectrophotometric determination of ruthenium using 1,10-phenanthroline was modified and used for quantification of the ruthenium content in complexes. Complexes were decomposed by using aqua regia and a full recovery of ruthenium from thus obtained solutions was observed at pH 6 after three hours of heating at 90 °C with a hundredfold excess of phenanthroline. The modified procedure has several important advantages compared to the originally reported procedure. It is faster and more accessible for laboratory practice since it does not require tedious RuO4 distillation. Also it has much wider linearity range (20 μg L−1 to 12 mg L−1 compared to 162 μg L−1 to 1.62 mg L−1) and lower limit of quantification (30.4 μg L−1 compared to 100 μg L−1). Moreover, recoveries of ruthenium are practically quantitative and the single standard addition method, instead of the calibration curve method, can be successfully used for accurate analysis.

Four new heteroleptic copper(II) complexes having chalcone or flavonol ligands and Schiff base (N-phenyl-5-chlorosalicylideneimine) as co-ligand were prepared, chemically and structurally characterized and investigated as functional biomimetic catecholase models. The complexes were prepared by the solution synthesis and crystal and molecular structures were determined by X-ray diffraction. Complexes were chemically characterized by elemental analysis, infrared and electronic absorption spectroscopy as well as by electrochemical measurements. Copper(II) chalcone complexes, with square-pyramidal CuO4N core, are binuclear, featuring phenolate oxygen from the Schiff base as a bridging atom, while copper(II) flavonol complexes are mononuclear, and reveal a square planar CuO3N coordination core. Catalytic activity of the complexes in 3, 5-di-tert-butylcatechol oxidation was confirmed by spectrophotometric and electrochemical measurements. Kinetic measurements revealed that the binuclear (chalcone-containing) complexes have enhanced catalytic activity as compared to the mononuclear Cu(II) flavonol complexes. Relatively high kcat values (300 – 750 h–1) confirmed their respectable biomimetic catecholase-like activity.

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