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In this paper, three different Zn(II) complexes with (E)-2-(2-(1-(6-bromopyridin-2-yl)ethylidene)hydrazinyl)-N,N,N-trimethyl-2-oxoethan-1-aminium chloride (HLCl) have been synthesized and characterized by single crystal X-ray diffraction, elemental analysis, IR and NMR spectroscopy. All complexes are mononuclear, with the ligand (L) coordinated in a deprotonated formally neutral zwitterionic form via NNO donor set atoms. Complex 1 forms an octahedral geometry with the composition [ZnL2](BF4)2, while complexes 2 [ZnL(NCO)2] and 3 [ZnL(N3)2] form penta-coordinated geometry. Density functional theory (DFT) calculations were performed to enhance our understanding of the structures of the synthesized complexes and the cytotoxic activity of the complexes was tested against five human cancer cell lines (HeLa, A549, MDA-MB-231, K562, LS 174T) and normal human fibroblasts MRC-5. Additionally, antimicrobial and antifungal activity of these complexes was tested against a panel of Gram-negative and Gram-positive bacteria, two fungal strains, and a yeast strain. It is noteworthy that all three complexes show selective antifungal activity comparable to that of amphotericin B. Molecular docking analysis predicted that geranylgeranyl pyrophosphate synthase, an enzyme essential for sterol biosynthesis is the most likely target for inhibition by the tested complexes.

Metals and metal oxides have subpar antibacterial activities compared to those of small-molecule antibiotics, yet there are hopes that with proper compositional and structural adjustments this gap might be bridged. In this study, titanium dioxide (TiO2) nanoparticles were mechanically activated and combined with particulate silver through simple reduction process elicited by UV irradiation and assisted with the ultrasound. The resulting powders in various combinations (Ag vs. no Ag, activated vs. non-activated) were characterized using a range of experimental techniques and assessed for their antibacterial activities. The preparation procedure presented in this work prevails over the disadvantages of many chemical routes, most critically by avoiding the use of toxic substances. The mechanical activation did not reduce the particle size or crystallinity of TiO2 nor did it consistently alter the bandgap, yet it enabled the doubling of the amount of silver incorporable into the material. Further, while both mechanical activation and the addition of silver in the amount not exceeding 0.5 wt% produced barely detectable structural changes in the material, they both augmented its antibacterial activity. The precursor TiO2 powder produced no inhibition zone against any of the four bacterial species tested, while the mechanical activation of TiO2 led to the formation of distinct inhibition zones against each of the four bacterial species tested. The addition of silver to activated TiO2 further widened the inhibition zones and it also imparted the antibacterial activity to non-activated TiO2. The boost in the antibacterial activity achieved by the short mechanical activation was of a similar magnitude as the boost obtained after the addition of silver. The antibacterial activity was not different for different species when no silver was added to the system. However, with the addition of silver, species selectivity was obtained, as the composites were more effective against th

The condensation product of 7-acetyl-6-azaindole and Girard’s T reagent ((E)-2-(2-(1-(1H-pyrrolo[2,3-c]pyridin-7-yl)ethylidene)hydrazineyl)-N,N,N-trimethyl-2-oxoethan-1-aminium, HL ligand) was used as a ligand in the reaction with Cu(BF4)2·6H2O and NaN3. The reaction led to the formation of a binuclear Cu(II) complex containing two end-to-end (di-m-1,3-N3) azide bridges, as well as two NNO-donor hydrazone ligands, forming an axially elongated square pyramidal geometry around each Cu(II) center. This end-to-end (di-m-1,3-N3) azide bridge binding mode has not yet been reported, in Cu(II) complexes containing the NNO-donor hydrazone ligands, which makes the structure of the complex even more interesting for further studies. The com­plex was characterized by elemental analysis, IR spectroscopy and X-ray crys­tal­lography, and it was found that it crystallizes in the triclinic space group P–1 with the asymmetric unit comprising one Cu(II) centre, zwitterionic ligand L, one azide (N3-) ligand and BF4- counter anion. Examination of antimicrobial activity of the complex shows higher antifungal and antibacterial activity towards tested Gram-positive bacteria in comparison to the hydrazone ligand, with the antifungal activity of the complex even being comparable to the act­ivity of amphotericin B.

In the reaction of 3-aminothymoquinone and aromatic aldehydes, two benzoxazole derivatives viz. 2-(4-methoxyphenyl)-4-methyl-7-isopropyl-1,3-benzoxazol-5-ol (1) and 2-(4-trifluoromethyl)-4-methyl-7-isopropyl-1,3-benzoxazol-5-ol (2) were prepared and characterized by elemental analysis, infrared and 1H, and 13C-nuclear magnetic resonance spectroscopy and mass spectrometry. Their antimicrobial activity against Escherichia coli, Salmonella enterica, Proteus hauseri, Pseudomonas aeruginosa, Staphylococcus aureus, Sarcina lutea, Clostridium sporogenes and Bacillus subtilis was tested. Synthesized compounds show the best activity on Sarcina lutea, and the lowest against Proteus hauseri and Clostridium sporogenes. The paper assesses in silico methods of the possible ways selected derivatives bind to the enzyme deoxyribonucleic acid gyrase (1KZN). The docking results were compared with those obtained from in vitro antimicrobial activity. Molecular properties and absorption, distribution, metabolism and excretion parameters were also calculated for compounds. The difference in the obtained values reflects differences in the derivatives structures. In the future, tests on a number of enzymes crucial for bacterial life as well as a number of derivatives may offer further information on the mechanisms of action of these substances.

Interest in Cd complexes has been growing in recent years. Cd complexes are considered a potential solution in the search for novel antibiotics that can fight antimicrobial resistance. In addition, Cd complexes draw attention to material chemistry. The main objective of this work was to prepare the first Cd(II) complexes with anionic forms of pyridine-based thiazolyl hydrazone (THs) ligands HLS2 [(E)-4-(4-methoxyphenyl)-2-(2-[pyridine-2-ylmethylene]hydrazinyl)thiazole] and HLS3 [(E)-2-(2-[pyridine-2-ylmethylene]hydrazinyl)-4-(p-tolyl)thiazole] and perform their structural and spectroscopic characterization, as well as stability in solution and upon heating. Studies related to their biological activities and possible electrochromic applications are also being conducted. Complexes [Cd(HLS2)2] (1) and [Cd(HLS3)2] (2) have been characterized by a single-crystal X-ray diffraction and computational analysis of intermolecular interactions responsible for their solid-state structures was performed. Thermal stability of 1 and 2 in the solid-state was analyzed by TGA/MS, where as their solution stability was determined by the spectrophotometric titration method. Electrochemical and in situ UV–Vis spectroelectrochemical analyses of 1 and 2 were carried out to determine redox mechanisms and the influence of the substituents and electrolytes on their redox responses. The antioxidant capacity of both complexes was tested in antioxidant assays, while their antimicrobial activity was tested against five Gram-positive and four Gram-negative bacteria, as well as against three fungi. The obtained results indicate their potent antioxidant capacity. The antimicrobial activity of investigated compounds on almost all tested bacterial strains was stronger than that of the standard antibiotic erythromycin. The results of docking studies indicate that the minor groove DNA is the possible biological target of 1 and 2.

Fe(III) and Mn(II) complexes with condensation product of thiosemicarbazide and 2-acetylthiazole (HL1, (E)-2-(1-(thiazol-2-yl)ethylidene)hydrazine-1-carbothioamide) have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental analysis. In both complexes, the thiosemicarbazone ligand is coordinated in deprotonated form through the NNS donor set of atoms. However, while Fe(III) complex is in the doublet ground state with distorted octahedral geometry, the coordination environment around Mn(II) is distorted trigonal-prismatic, and the sextet state is found to be the ground state. DFT calculations were performed to rationalize spin state preferences, and continuous shape measure describes the deviation from ideal six-coordinated polyhedral geometries in the ground and excited states. Antimicrobial activity (against a panel of Gram-negative and Gram-positive bacteria, two yeast, and one fungal strain), brine shrimp assay, and DPPH radical scavenging activity of both complexes were evaluated, and these results relate to the electronic structure of the complexes., Additional crystallographic and computational results, and the Cartesian coordinates of all DFT optimized structures

The condensation product of 7-acetyl-6-azaindole and Girard's T reagent ((E)-2-(2-(1-(1H-pyrrolo[2,3-c]pyridin-7-yl)ethylidene)hydrazineyl)-N,N,N-trimethyl-2-oxoethan-1-aminium, HL ligand) was used as a ligand in the reaction with Cu(BF4)2·6H2O and NaN3. The reaction led to the formation of a binuclear Cu(II) complex containing two end-to-end (di-m-1,3-N3) azide bridges, as well as two NNO-donor hydrazone ligands, forming an axially elongated square pyramidal geometry around each Cu(II) center. This end-to-end (di-m-1,3-N3) azide bridge binding mode has not yet occurred in Cu(II) complexes containing the NNO-donor hydrazone ligands, which makes the structure of the complex even more interesting for further studies. The complex was characterized by elemental analysis, IR spectroscopy and X-ray crystallography, and it was found that it crystallizes in the triclinic space group P–1 with the asymmetric unit comprising one Cu(II) centre, zwitterionic ligand L, one azide (N3−) ligand, and BF4− counter anion. Examination of antimicrobial activity of the complex shows higher antifungal and antibacterial activity towards tested Gram-positive bacteria in comparison to the hydrazone ligand, with the antifungal activity of the complex even being comparable to the activity of amphotericin B.

Earth-abundant, cheap and non-toxic zinc-based coordination compounds are drawing research attention as promising candidates for various applications, such as photoluminescent materials and anticancer agents. In this paper we report six zinc complexes (1–3-NO3 and 1–3-Cl) with pyridyl-based thiazolyl–hydrazone ligands, which differ in the nature of substituents at the ligands' periphery, anion type, and geometry around the metal ion. The complexes were characterized by single-crystal and powder X-ray diffraction analysis, as well as IR and NMR spectroscopy. The symmetrical complexes 2-Cl and 3-Cl, where zinc atoms are located at a two-fold axis, do not exhibit photophysical properties, unlike their asymmetrical analogs 2-NO3 and 3-NO3 with the same complex cation. Asymmetrical pentacoordinated 1-Cl and hexacoordinated 1-NO3 complexes exhibit photophysical properties. An admixture of allowed intra-ligand (1IL) and chloro (X)-to-ligand charge-transfer (1XLCT) electronic transitions is responsible for the fluorescence of the 1-Cl complex. The origin of the emission of the 1-NO3 complex is ascribed to an admixture of 3IL and ligand-to-ligand charge-transfer (3LLCT) forbidden electronic transitions, while for 3-NO3 most electronic excitations are of LLCT character. The thermal stability of the complexes is in accord with the strength of respective intermolecular interactions. The antiproliferative activity of the complexes was in the nanomolar range on some of the investigated cancer cell lines. Contrary to the increase of antiproliferative activity of the complexes in comparison to the free ligands in cancer cell lines, an acute toxicity determined in the brine shrimp assay follows the opposite trend. The overall results suggest that Zn(II) thiazoyl–hydrazone complexes have considerable potential as multifunctional materials.

Sintetisana su dva ariltio i dva aralkiltio derivata 2-terc-butil-1,4-benzohinona reakcijom Michael-ove adicije tiola na hinonsko jezgro u etanolu. Dobijenim derivatima je ispitana antimikrobna i antioksidativna aktivnost, kao i toksinost na raie Artemia salina. Najjau antimikrobnu aktivnost je pokazao derivat 4, najveu antioksidativnu aktivnost je imao derivat 2 (IC50=0,0526 mM), dok je toksinost prema raiima ispoljio samo derivat 4 (LC50=0,032 mM)., Two arylthio and aralkylthio derivatives of 2-tert-butyl-1.4-benzoquinone were synthesized by Michael addition of thiols on quionone moiety in ethanol. For all compounds antimicrobial and antioxidant activity was investigated, as well as toxicity towards nauplii of Artemia salina. Derivative 4 showed the strongest antimicrobial activity, derivative 2 showed the most intense antioxidant activity (IC50=0.0526 mM), while only derivative 4 showed toxicity against nauplii of A. salina (LC50=0.032 mM).

Usled stalne potrebe za novim antitumorskim lekovima, počevši od androstanskog bis(semikarbazona), sintetisan je novi bis(karbazatni) estar (bisKBZ) za koji je određena antimikrobna aktivnost, citotoksična aktivnost na tri maligne ćelijske linije, i urađen je brine shrimp test toksičnosti. Novo jedinjenje se nije pokazalo kao dobar antimikrobni agens, ispoljilo je umerenu citotoksičnost prema testiranim ćelijskim linijama i pokazalo se kao pet puta manje toksično od cisplatina za račiće Artemia salina što je u dobroj korelaciji sa citotoksičnošću prema HeLa ćelijskoj liniji., Due to the constant need for new antitumor drugs, starting from androstane bis(semicarbazone), a new bis(carbazate) ester (bis-KBZ) was synthesized; antimicrobial activity and cytotoxicity against three malignant cell lines were determined, and the brine shrimp toxicity test was performed. The new compound did not prove to be a good antimicrobial agent, it showed moderate cytotoxicity to the tested cell lines, and proved to be five times less toxic than cisplatin to Artemia salina, which correlates well with the cytotoxicity to HeLa cell line.

Kompleks Cu(II) sa kondenzacionim derivatom 2-acetilpiridina i dihidrazida malonske kiseline (H2L) je dobijen direktnom sintezom. Prekristalizacijom je dobijen monokristalni proizvod te je struktura kompleksa rešena primenom rendgenske strukturne analize. U unutrašnjoj sferi binuklearnog simetrinog kompleksa, sa distorgovanom oktaedarskom geometrijom oko jona Cu(II), jedan molekul liganda je koordinovan u anjonskom, a drugi u neutralnom obliku, oba bis-tridentatno preko N,N,O seta donorskih atoma. U spoljašnjoj sferi kompleksa se nalaze perhloratni joni i molekuli vode. Kompleks je pokazao antimikrobnu aktivnost u niskom mikromolarnom opsegu na svim testiranim mikroorganizmima., The Cu(II) complex with the ligand H2L, which is a condensation derivative of 2-acetylpyridine and malonic acid dihydrazide, was obtained by direct synthesis. Recrystallization gave a single crystal product, and the structure of the complex was solved by X-ray structural analysis. In the inner sphere of the binuclear symmetrical complex, with distorted octahedral geometry around Cu(II) ions, one ligand molecule is coordinated in anionic and the other in neutral form, both bis-tridentaly via the N, N, O set of donor atoms. Perchlorate ions and water molecules are located in the outer sphere of the complex. The complex showed antimicrobial activity in the low micromolar range on all tested microorganisms.

Ciljevi ove studije bili su: 1) ispitivanje citotoksičnog potencijala različitih estara linoleinske kiseline (butil-, pentil-, heksil-, heptil-, oktil-, nonil-, fentil- i 3-fenilpropil- linoleat) detektovanih u odbrambenim sekretima dve vrsta stonoga iz reda Julida - Megaphyllum unillineatum (C. L. Koch, 1838) i M. bosniense (Verrhoeff, 1897) na vijabilnost ćelija raka debelog creva (SW480) i 2) analiza vijabilnost SW480 ćelija nakon tretiranja ekstraktima odbrambenih sekreta pomenutih vrsta.

Earth-abundant, cheap and non-toxic zinc-based coordination compounds are drawing research attention as promising candidates for various applications, such as photoluminescent materials and anticancer agents. In this paper we report six zinc complexes (1–3-NO3 and 1–3-Cl) with pyridyl-based thiazolyl–hydrazone ligands, which differ in the nature of substituents at the ligands' periphery, anion type, and geometry around the metal ion. The complexes were characterized by single-crystal and powder X-ray diffraction analysis, as well as IR and NMR spectroscopy. The symmetrical complexes 2-Cl and 3-Cl, where zinc atoms are located at a two-fold axis, do not exhibit photophysical properties, unlike their asymmetrical analogs 2-NO3 and 3-NO3 with the same complex cation. Asymmetrical pentacoordinated 1-Cl and hexacoordinated 1-NO3 complexes exhibit photophysical properties. An admixture of allowed intra-ligand (1IL) and chloro (X)-to-ligand charge-transfer (1XLCT) electronic transitions is responsible for the fluorescence of the 1-Cl complex. The origin of the emission of the 1-NO3 complex is ascribed to an admixture of 3IL and ligand-to-ligand charge-transfer (3LLCT) forbidden electronic transitions, while for 3-NO3 most electronic excitations are of LLCT character. The thermal stability of the complexes is in accord with the strength of respective intermolecular interactions. The antiproliferative activity of the complexes was in the nanomolar range on some of the investigated cancer cell lines. Contrary to the increase of antiproliferative activity of the complexes in comparison to the free ligands in cancer cell lines, an acute toxicity determined in the brine shrimp assay follows the opposite trend. The overall results suggest that Zn(II) thiazoyl–hydrazone complexes have considerable potential as multifunctional materials.

Interest in Cd complexes has been growing in recent years. Cd complexes are considered a potential solution in the search for novel antibiotics that can fight antimicrobial resistance. In addition, Cd complexes draw attention to material chemistry. The main objective of this work was to prepare the first Cd(II) complexes with anionic forms of pyridine-based thiazolyl hydrazone (THs) ligands HLS2 [(E)-4-(4-methoxyphenyl)-2-(2-[pyridine-2-ylmethylene]hydrazinyl)thiazole] and HLS3 [(E)-2-(2-[pyridine-2-ylmethylene]hydrazinyl)-4-(p-tolyl)thiazole] and perform their structural and spectroscopic characterization, as well as stability in solution and upon heating. Studies related to their biological activities and possible electrochromic applications are also being conducted. Complexes [Cd(HLS2)2] (1) and [Cd(HLS3)2] (2) have been characterized by a single-crystal X-ray diffraction and computational analysis of intermolecular interactions responsible for their solid-state structures was performed. Thermal stability of 1 and 2 in the solid-state was analyzed by TGA/MS, where as their solution stability was determined by the spectrophotometric titration method. Electrochemical and in situ UV–Vis spectroelectrochemical analyses of 1 and 2 were carried out to determine redox mechanisms and the influence of the substituents and electrolytes on their redox responses. The antioxidant capacity of both complexes was tested in antioxidant assays, while their antimicrobial activity was tested against five Gram-positive and four Gram-negative bacteria, as well as against three fungi. The obtained results indicate their potent antioxidant capacity. The antimicrobial activity of investigated compounds on almost all tested bacterial strains was stronger than that of the standard antibiotic erythromycin. The results of docking studies indicate that the minor groove DNA is the possible biological target of 1 and 2.

The biological activity of Cd compounds has been investigated scarce since Cd has been recognized as a human carcinogen. However, the toxicity of cadmium is comparable to the toxicity of noble metals such as Pt and Pd. The paradigm of metal toxicity has been challenged suggesting that metal toxicity is not a constant property, yet it depends on many factors like the presence of appropriate ligands. Studies on anticancer activity of cadmium complexes showed that the complexation of various ligands resulted in complexes that showed better activities than approved drugs. In the present study, cadmium complexes with biologically potent thiazolyl/selenazoyl-hydrazone ligands have been prepared, and tested for their activity against different types of tumor cell models. The complexation of ligands with Cd(II) resulted in a synergistic effect. The antiproliferative activity study revealed that all complexes are more active compared to 5-fluorouracil and cisplatin. The mechanism of tumor cell growth inhibition reveal that selenium-based compounds induce cell death in T-47D (gland carcinoma) cells through apoptosis via caspase-3/7 activation. Additionally, their pro-apoptotic effect was stronger compared to etoposide and cisplatin. Nuclease activity, detected by gel electrophoresis, may be the possible mechanism of anticancer action of investigated complexes.