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In the present work, the α, β-double bond of the aroylacrylic acid phenylamides was suitably modified to optimize the toxicity–antiproliferative activity ratio of the resulting compounds 1 –5 . The phenylamides were modified by Michael’s addition of suitably chosen piperidine-containing fragments: 1-amino-N- benzylpiperidine ( a1 ), 4-benzylpiperidine ( a2 ), and N , N -dimethyl- N -[2-(1-piperazinyl)-ethyl]amine ( a3 ). The compounds exerted micromolar activity toward three cancer cell lines, A549, LoVo, and Skov-3, caus- ing apoptotic cell death. It was shown that the nature of the cyclic amine moiety at position C2 of the compounds is probably the primary determinant of anticancer activity toward tested cell lines and the acute toxicity toward brine shrimp ( Artemia salina ). The majority of compounds revealed the ability to vigorously induce mitochondrial superoxide anion generation in all treated cell lines, which together with cell cycle arrest at the S phase and activation of intrinsic caspase cascade, indicates the possibility that apoptosis was triggered due to irreparable chromosomal damage by acute oxidative stress. Two deriva- tives also exerted significant antibacterial activity with one order of magnitude higher potency than chlo- ramphenicol in most of the investigated bacterial strains. Also, the drug-like properties for all compounds were estimated by available software tools. This is the peer-reviewed version of the article: Vujatović, Tamara B., Vitorović - Todorović, Maja D., Cvijetić, Ilija, Vasović, Tamara, Nikolić, Milan R., Novaković, Irena, Bjelogrlić, Snežana, "Novel derivatives of aroylacrylic acid phenylamides as inducers of apoptosis through the ROS-me diate d pathway in several cancer cell lines" in Journal of Molecular Structure, 1250 (2022):131702, [https://doi.org/10.1016/j.molstruc.2021.131702] The published version: [https://cer.ihtm.bg.ac.rs/handle/123456789/4853]

Three ruthenium-bipyridine complexes (1–3) carrying acetylpyridine ligand unit were synthesized in methanol via the reaction of [RuCl2(bpy)2] with corresponding acetylpyridine (2-, 3-, and 4-acpy). Obtained complexes were characterized by (1H and 13C) NMR and IR spectroscopy, MS spectrometry, UV‒vis spectrophotometry, and cyclic voltammetry. Their structural characterization revealed bidentate coordination mode for 2-acpy while 3- and 4-acpy acted as monodentate ligands. The electrochemical profile of newly synthesized compounds was investigated by cyclic voltammetry which confirmed their electrochemical activity. Voltammetric responses within the −1.20 < Ep < 1.50 V range of potentials were summarized in two major events: Ru(II)→Ru(III) oxidation spotted at app. ΔEp = 0.65 V and successive reductions of bpy units located from ‒0.79 V to 0.47 V (vs. Ag/AgCl (3 M) electrode). The DNA-binding activity of the complexes was evaluated by both UV‒vis spectrophotometry and cyclic voltammetry indicating DNA-intercalation with a slight contribution of electrostatic interactions. Furthermore, antimicrobial activity was tested against bacterial and fungal strains, for which moderate activity was observed. Assessment of in vitro toxicity against freshly hatched nauplii of Artemia salina as well as radical scavenging capacity was evaluated. The test compounds showed neither toxicity nor antioxidant activity.

In this paper, Cu(II), Mn(II) and Zn(II) complexes with N,N,N-trimethyl-2-oxo-2-(2-(1-(thiazol-2-yl)ethylidene)hydrazinyl)ethan-1-aminium chloride (HL1Cl) were synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and DFT calculations. In all three complexes, a ligand (L1) is coordinated in a deprotonated formally neutral zwitterionic form via NNO donor set atoms. Cu(II) and Zn(II) form mononuclear penta-coordinated complexes [CuL1(N3)(CH3OH)]BF4 and [ZnL1(N3)2], respectively, while Mn(II) forms a binuclear [Mn2L12(μ-1,1-N3)2(N3)2]·2CH3OH complex, with unusual distorted trigonal-prismatic geometry around the metal centers. The antimicrobial activity of these complexes was tested against a panel of Gram-negative and Gram-positive bacteria, two yeasts and one fungal strain. The binuclear Mn(II) complex showed antifungal activity of similar intensity to amphotericin B. Based on the results of the brine shrimp test and DPPH radical scavenging activity, the most active Cu(II) and Mn(II) complexes were selected for evaluation of cytotoxic activity against five malignant cancer cell lines (HeLa, A375, MCF7, PC-3 and A549) and one normal cell line HaCaT. Both complexes showed significant activity. It should be pointed out that the activity of the Mn(II) complex against the MCF7 breast cancer cell line is only slightly weaker than that of cisplatin, but with selectivity to the tumor cell line in comparison to normal HaCaT cells, which is non-existent in the case of cisplatin. Supporting information: [https://cer.ihtm.bg.ac.rs/handle/123456789/4902] Related crystallographic data (CCDC 2110386): [https://cer.ihtm.bg.ac.rs/handle/123456789/4903] Related crystallographic data (CCDC 2110387): [https://cer.ihtm.bg.ac.rs/handle/123456789/4904] Related crystallographic data (CCDC 2110388): [https://cer.ihtm.bg.ac.rs/handle/123456789/4905]

Interest in Cd complexes has been growing in recent years. Cd complexes areconsidered a potential solution in the search for novel antibiotics that can fightantimicrobial resistance. In addition, Cd complexes draw attention to materialchemistry. The main objective of this work was to prepare the firstCd(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 characteri-zation, as well as stability in solution and upon heating. Studies related to theirbiological activities and possible electrochromic applications are also beingconducted. Complexes [Cd(HLS2)2](1) and [Cd(HLS3)2](2) have been charac-terized by a single-crystal X-ray diffraction and computational analysis of inter-molecular interactions responsible for their solid-state structures wasperformed. Thermal stability of1and2in the solid-state was analyzed byTGA/MS, where as their solution stability was determined by the spectropho-tometric titration method. Electrochemical andin situUV–Vis spectroelectro- chemical analyses of1and2were carried out to determine redox mechanismsand 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 andfour Gram-negative bacteria, as well as against three fungi. The obtainedresults indicate their potent antioxidant capacity. The antimicrobial activity ofinvestigated compounds on almost all tested bacterial strains was strongerthan that of the standard antibiotic erythromycin. The results of docking stud-ies indicate that the minor groove DNA is the possible biological target of1and2.KEYWORDSantimicrobial activity, Cd(II) complex, docking, in situspectroelectrochemistry, thiazolylhydrazonesReceived: 18 July 2022Revised: 14 October 2022Accepted: 20 October 2022DOI: 10.1002/aoc.6942Appl Organomet Chem.2023 ; 37:e6942.wileyonlinelibrary.com/journal/ aoc© 2022 John Wiley & Sons Ltd.1of20https://doi.org/10.1002/aoc.6942

(Thiazolyl-2-yl)hydrazones (THs) are a group of organic compounds containing both hydrazone and 1,3-thiazole pharmacophores present in many approved drugs. They have been investigated greatly in recent years due to potent anticancer, antibacterial, antifungal, antituberculosis, anti-inflammatory, and antiparasitic activities. In this study, one pyridine-based and two quinoline-based, novel THs were synthesized and characterized by elemental analysis, Fourier-transform infrared spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR). The antimicrobial activity of the compounds was tested against five Gram-positive and five Gram-negative bacteria, as well as against three fungi. The antioxidant capacity of the compounds was tested in six antioxidative assays. The results showed that quinoline-based THs were more active against tested Gram-negative bacteria and fungi strains than pyridine-based compounds. All the compounds showed excellent antioxidative activity comparable to or greater than the used standards (vitamin C and Trolox). Absorption, distribution, metabolism, excretion, and toxicity (ADMET) parameters were calculated in-silico. Results pointed to promising good pharmacokinetics profiles of investigated compounds, especially 2-quinoline carboxaldehyde-based compound, which can be a lead drug candidate. (Tiazolil-2-il)-hidrazoni (TH) su grupa organskih jedinjenja koja sadrže i hidrazon i 1,3-tiazol farmakofore koje su prisutne u mnogim odobrenim lekovima. Poslednjih godina se u velikoj meri istražuju zbog jakih antikancerogenih, antibakterijskih, antifungalnih, antituberkuloznih, antiinflamatornih i antiparazitskih aktivnosti. U ovoj studiji, sintetisan je jedan novi TH na bazi piridina i dva na bazi hinolina, koji su okarakterisani elementalnom analizom, infracrvenom spektroskopijom sa Furijeovom transformacijom (FTIR) i spektroskopijom nuklearne magnetne rezonancije (NMR). Antimikrobna aktivnost jedinjenja je testirana na pet Gram-pozitivnih i pet Gram-negativnih bakterijskih sojeva, kao i na tri soja gljivica. Šest antioksidativnih testova je korišćeno za određivanje antioksidativnog kapaciteta sintetisanih jedinjenja. Rezultati su pokazali da su TH na bazi hinolina aktivniji prema testiranim Gram-negativnim sojevima bakterija i prema gljivicama, nego jedinjenja na bazi piridina. Sva jedinjenja su pokazala odlično antioksidativno dejstvo, uporedivo ili veće od korišćenih standarda (vitamin C i troloks). Parametri apsorpcije, distribucije, metabolizma, izlučivanja i toksičnosti (ADME) izračunati su in-silico. Rezultati ukazuju na dobre farmakokinetičke profile ispitivanih jedinjenja, posebno jedinjenja na bazi 2-hinolinkarboksaldehida koje ima potencijal da bude kandidat za osnovno jedinjenje (engl. lead compound).

In this work, Pt(II) complexes of previously synthesized steroidal thiosemicarbazones were synthesized and characterized. The ligands and their metal complexes were studied by analytical and spectroscopic data (elemental analysis, IR, 1D NMR and 2D NMR, HSQC, HMBC, NOESY, COSY), the analysis of which enabled complete 1H and 13C assignments of each compound including E and Z isomers. All the synthesized ligands and complexes were screened for their cytotoxic and antimicrobial activity. The results demonstrate that new steroidal thiosemicarbazone complexes were significantly less cytotoxic than corresponding steroidal thiosemicarbazones. Also, complexes show lower antimicrobial activity than the standard drugs, similar to the activity of the starting thiosemicarbazones. Почевши од претходно синтетисаних стероидних тиосемикарбазона, у овом раду су синтетисани и окарактерисани комплекси платине(II). Лиганди и њихови метални комплекси проучавани су аналитичким и спектроскопским методама (елементална анализа, ИЦ, 1D NMR и 2D NMR, HSQC, HMBC, NOESY, COSY). Анализом добијених података омогућена је потпуна 1H и 13C асигнација свих једињења укључујући Е и Z изомере. За синтетисане лиганде, као и њихове комплексе испитивана је цитотоксична и антимикробна активност. Резултати указују на то да нови стероидни тиосемикарбазонски комплекси испољавају значајно нижу цитотоксичност од одговарајућих стероидних тиосемикарбазона. Поред тога, комплекси поседују антимикробну активност сличну активности полазних тиосемикарбазона, a нижу од стандардних лекова

In this work synthesis, characterization and crystal structures of 1, Zn(II) complex ([ZnL1(NCS)2]), with (E)-1-(2-oxo-2-(2-(quinolin-2-ylmethylene)hydrazinyl)ethyl)pyridin-1-ium chloride (HL1Cl) and 2, Bi(III) complex ([BiHL2Cl4] × 1/2CH3OH), with (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(thiazol-2-yl)ethylidene)hydrazinyl)ethan-1-aminium chloride (HL2Cl), have been reported. Zn(II) complex possesses a distorted trigonal bipyramidal geometry while surroundings around Bi(III) ion are extended pentagonal bipyramidal. Antimicrobial activity, brine shrimp assay and DPPH radical scavenging activity of both complexes, including previously synthesized complexes with HL2Cl ligand (Zn(II) and Ni(II)) and complexes with (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-aminium chloride (HL3Cl) (Zn(II), Cu(II), Cd(II), Co(II), Fe(III), Ni(II)), were evaluated. For the most active complexes, cytotoxic activity against five malignant cancer cell lines (HeLa, A375, MCF7, PC-3 and A549) and normal cell line HaCaT, as well as generation of reactive oxygen species (ROS), was tested. Supplementary material: [https://cherry.chem.bg.ac.rs/handle/123456789/4675]

In this study, mutagenic and genotoxic potential of anti-tumor compounds avarol, avarone, and its derivatives 3'-methoxyavarone, 4'-(methylamino)avarone and 3'-(methylamino)avarone was evaluated and compared to cytostatics commonly used in chemotherapy (5-fluorouracil, etoposid, and cisplatin). Mutagenic potential of selected hydroquinone and quinones was assessed in prokaryotic model by the SOS/umuC assay in Salmonella typhimurium TA1535/pSK1002. Genotoxic potential was also assessed in eukaryotic models using comet assay in human fetal lung cell line (MRC-5), human adenocarcinoma epithelial cell line (A549), and in human peripheral blood cells (HPBC). The results indicated that avarol and avarone do not exert mutagenic/genotoxic potential. Among the studied avarone derivatives, mutagenic potential was detected by SOS/umuC test for 3'-(methylamino)avarone, but only after metabolic activation. The results of comet assay indicated that 3'-methoxyavarone and 3'-(methylamino)avarone have a significant impact on the level of DNA damage in the MRC-5 cell line. Genotoxic potential was not observed in A549 cells or HPBC probably due to a different uptake rate for the compounds and lower in metabolism rate within these cells. This is an Accepted Manuscript of an article published by Taylor & Francis in Drug and Chemical Toxicology on 04 Jan 2018, available online: [http://www.tandfonline.com/10.1080/01480545.2017.1413108].

In this paper, the synthesis of fourteen alkylamino and arylamino derivatives of sesquiterpene quinone avarone and its model compound tert-butylquinone is described. Branched, cyclic, allylic and benzylic alkylamino/arylamino groups were introduced into the quinone moiety. For all the obtained derivatives, their biological activity and redox properties were studied. The cytotoxic activity of the synthesized derivatives towards multidrug resistant (MDR) human non-small cell lung carcinoma NCI-H460/R cells, their sensitive counterpart NCI-H460 and human normal keratinocytes (HaCaT) was investigated. The antimicrobial activity towards Gram-positive and Gram-negative bacteria, and fungal cultures was determined. Some of the synthesized derivatives showed selectivity for cancer cells, including MDR cells. Regarding their cell death induction potential, the most promising compounds were allylamino derivatives, preferentially triggering apoptosis, with high selectivity for cancer cells, including MDR cells. Several compounds showed promising antimicrobial activity, comparable to those of commercial antibiotic and antimycotic agents.

Fourteen mono- and bis-carbohydrazone ligands have been synthesized and characterized. Antioxidant activity of the substances was investigated together with possible (E)/(Z) isomerization, and explained on the most active antioxidant compound 4 in various dimethyl sulphoxide–water mixtures. The addition of water to the system was involved in the formation of hydrated molecules which was confirmed in NMR after the addition of D2O. The ligands were tested in vitro against Gram-positive and Gram-negative bacteria and fungi, and their activity was discussed in relation to the structure of investigated carbohydrazone. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172013]

This paper discusses antioxidative and biological activities of 25 novel amidino substituted benzamides with a variety of heteroaromatic nuclei attached to the benzamide moiety and with a variable number of methoxy or hydroxy substituents. Targeted compounds, bearing either amidino or 2-imidazolinyl substituent, were obtained in the Pinner reaction from cyano precursors. 3D-QSAR models were generated to predict antioxidative activity of the 25 novel aromatic and heteroaromatic benzamide derivatives. The compounds were tested for antioxidative activity using in vitro spectrophotometric assays. Direct validation of 3D-QSAR approach for predicting activities of novel benzamide derivatives was carried out by comparing experimental and computationally predicted antioxidative activity. Experimentally determined activities for all novel compounds were found to be within a standard deviation of error of the models. Following this, structure–activity relationships among the synthesized compounds are discussed. Furthermore, antiproliferative activity in vitro against HeLa cells as well as antibacterial and antifungal activity was tested to confirm the other biological activities of the prepared compounds. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3852] This is the peer-reviewed version of the following article: Sović, I.; Cindrić, M.; Perin, N.; Boček, I.; Novaković, I. T.; Damjanović, A.; Stanojković, T.; Zlatović, M.; Hranjec, M.; Bertoša, B. Biological Potential of Novel Methoxy and Hydroxy Substituted Heteroaromatic Amides Designed as Promising Antioxidative Agents: Synthesis, 3D-QSAR Analysis, and Biological Activity. Chemical Research in Toxicology 2019, 32 (9), 1880. [https://doi.org/10.1021/acs.chemrestox.9b00256]

Eleven new steroidal mono- and bis(semicarbazones)2a–e, 4d and 3a–e have been prepared starting from various 3-oxo-α,β-unsaturated steroids. Mono-semicarbazones 2a–e were further subjected to ethyl chloroacetate in boiling absolute ethanol but, instead of expected intramolecular cyclocondensation reaction products, the new carbazate esters 5a-e were obtained. The structures of all synthesized compounds and identification of each E/Z isomer were deduced by elemental analysis, HRMS, NMR, and IR spectroscopy. Preliminary screening for the cytotoxic activity in vitro of the new compounds has been conducted against three cancer cell lines, K562, Jurkat and HeLa cells. HeLa cells were the most sensitive while K562 cells were the least sensitive to the cytotoxic action of the novel steroid derivatives. Compounds 2e, 3c and 5e were found to have the best but still moderate cytotoxic effects. All tested compounds showed very weak antimicrobial activities. These results demonstrate that the replacement of thioxo group with carbonyl group in steroidal hydrazone derivatives resulted in decrease in their biological activity. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3083] This is peer-reviewed version of the following article: Živković, M. B.; Novaković, I. T.; Matić, I. Z.; Sladić, D. M.; Krstić, N. M. Synthesis and Preliminary Screening for the Biological Activity of Some Steroidal Δ4-Unsaturated Semicarbazone Derivatives. Steroids 2019, 148, 36–46. [https://doi.org/10.1016/j.steroids.2019.04.010]

In this work, synthesis of alkylamino and aralkylamino derivatives of sesquiterpene quinone avarone and its model compound tert-butylquinone was described. For all obtained derivatives biological activity was studied. Cytotoxic activity of the synthesized derivatives towards multidrug resistant MDR human non small cell lung carcinoma NCI-H460/R cells, their sensitive counterpart NCI-H460 and human normal keratinocytes (HaCaT) as well as detection of cell death superoxide anion generation were investigated. Antimicrobial activity towards Gram positive and Gram negative bacteria and fungal cultures was determined. The results showed that strong cytotoxic activity toward cancer cells was improved with simple avarone mimetics. Some derivatives were selective towards MDR cancer cells. The most active derivatives induced apoptosis in both cancer cell lines, but not in normal cells. Superoxide production was induced by 2,6-disubstituted compounds in MDR cancer cells and not by less active 2,5-disubstituted compounds and was accompanied by the collapse of the mitochondrial transmembrane potential. Two tert-butylquinone derivatives were particularly selective towards MDR cancer cells. Some tert-butylquinone derivatives exhibited a strong antimicrobial activity. This is the peer-reviewed version of the article: Jeremić, M., Pešić, M., Dinić, J., Bankovic, J., Novaković, I., Šegan, D.,& Sladić, D. (2016). Simple avarone mimetics as selective agents against multidrug resistant cancer cells. European Journal of Medicinal Chemistry, 118, 107-120. [https://doi.org/10.1016/j.ejmech.2016.04.011] Published version: [https://cer.ihtm.bg.ac.rs/handle/123456789/1862] Supplementary material: [https://cer.ihtm.bg.ac.rs/handle/123456789/4580]

Ten biologically active 2,2,5,5-tetramethyl-9-aryl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione derivatives were synthesized and their structures were confirmed by IR, 1H and 13C NMR spectroscopy and mass spectrometry. Synthesized compounds were scanned for their antioxidant, antimicrobial and antiproliferative activity. Antibacterial activity was tested by the diffusion and dilution method against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, while antifungal activity was tested against Candida albicans and Saccharomyces cerevisiae. Antiproliferative activity was tested against HeLa (cervical carcinoma), SW620 (colorectal adenocarcinoma, metastatic), hepatocellular carcinoma (HEpG2), lung carcinoma cells (A549) and mouse embryo fibroblast cell line (3T3). The best antioxidant activity showed compound 2 with two hydroxy groups substituted on phenyl ring in positions 2' and 3'. The best antimicrobial activity of all synthesized compounds showed compound 8, while the best antiproliferative activity showed compound 6. Results signify the importance of xanthene-1,8-dione derivatives as potential antioxidant and antiproliferative agents. This work is licensed under a Creative Commons Attribution 4.0 International License.

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 &beta, ) 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.

Due to the rise of microbial strains resistant to conventional therapies, there is an urgent need for finding the new antimicrobial chemotypes. Heterocyclic compounds such as thiocarbohydrazones (TCHs) are able to interact with many metalloenzymes essential for microbes, while sulfur atom increases lipophilicity which is generally positively correlated with potency. In this paper, we report antibacterial and antifungal activity of twenty-two TCHs toward eight bacterial and three fungal strains. Furthermore, three alignment independent 3D QSAR models based on descriptors derived from molecular interaction fields (MIFs) are developed in order to rationalize structure-activity relationships for activities of TCHs toward S. aureus, P. aeruginosa and C. albicans. Several structural fragments important for biological activity are recognized in each model, and structural modifications which could lead to increased potency are suggested. Designed structures will be synthesized accordingly and tested toward the same microbial strains in order to obtain more potent derivatives. The supporting information: [https://cer.ihtm.bg.ac.rs/handle/123456789/4480]

A series of new 5H-pyridobenzazepine and pyridobenzothiepine derivatives was synthesized by Pd-catalyzed formation of C-N and C-S bonds. All synthesized compounds were tested for their in vitro antimicrobial activity. The 5H-pyridobenzazepine derivatives showed better antibacterial and antifungal activity than corresponding 5H-dipyridoazepine analogs. Among the synthesized azepines, derivative 8 displayed potent activity against tested bacteria (MIC = 39-78 μg/mL), while azepine 12 showed promising antifungal activity (MIC = 156-313 μg/mL). The synthesized thiepine derivatives exhibited weak antibacterial activity, but showed pronounced antifungal activity. [Projekat Ministarstva nauke Republike Srbije, br. 172008]

The first Co(III) complexes with (1,3-selenazol-2-yl)hydrazones as an unexplored class of ligands were prepared and characterized by NMR spectroscopy and X-ray diffraction analysis. The novel ligands act as NNN tridentate chelators forming octahedral Co(III) complexes. The impact of structural changes on ligands' periphery as well as that of isosteric replacement of sulphur with selenium on the electrochemical and electronic absorption features of complexes are explored. To support the experimental data, density functional theory (DFT) calculations were also conducted. Theoretical NMR chemical shifts, the relative energies and natural bond orbital (NBO) analysis are calculated within the DFT approach, while the singlet excited state energies and HOMO-LUMO energy gap were calculated with time-dependent density functional theory (TD-DFT). The electrophilic f(-) and nucleophilic f(+) Fukui functions are well adapted to find the electrophile and nucleophile centres in the molecules. Both (1,3-selenazol-2-yl)- and (1,3-thiazol-2-yl) hydrazone Co(III) complexes showed potent antimicrobial and antioxidant activity. A significant difference among them was a smaller cytotoxicity of selenium compounds. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3095]

The synthesis and cytotoxic activities determination of new steroidal mono- and bis(thiazolidin-4-ones) 4a-f and 5a-f have been performed. Their anticancer action was also evaluated in comparison to previously synthesized and reported corresponding steroidal thiosemicarbazones. All compounds were obtained as stereoisomeric mixtures with different configuration (E or Z) in the hydrazone moiety at the C-3 position. After several consecutive crystallizations diastereomerically pure major (5)-isomers of mono-thiazolidin-4-ones were isolated. The structure and stereochemistry of 2,4-thiazolidinedione,2-[(17-oxoandrost-4-en-3-ylidene)hydrazone] were confirmed by X-ray analysis. A pathway for the formation of thiazolidin-4-one ring was proposed. The steroid thiazolidinone derivatives examined in this study exerted selective concentration-dependent cytotoxic activities on six tested malignant cell lines. Ten out of twelve examined compounds exhibited strong cytotoxic effects on K562 cells (IC50 values from 8.5 mu M to 14.9 mu M), eight on HeLa cells (IC50 values ranging from 8.9 mu M to 15.1 mu M) while against MDA-MB-361 cells six compouds exerted similar or even higher cytotoxic action (IC50 values from 12.7 mu M to 25.6 mu M) than cisplatin (21.5 mu M) which served as a positive control. Eight of these ten compounds showed high selectivity in the cytotoxic action against HeLa and K562 cancer cell lines when compared with normal human fibroblasts MRC-5 and normal human PBMC. The study of mechanisms of the anticancer activity of the two selected compounds, mono- and bis(thiazolidin-4-one) derivatives of 19-norandrost-4-ene-3,17-dione 4a and 5a, revealed that both of these compounds induced apoptosis in HeLa cells through extrinsic and intrinsic signalling pathways. Treatment of EA.hy926 cells with sub-toxic concentrations of these compounds led to the inhibition of cell connecting and sprouting, and tube formation. The synthesized compounds exhibited poor antioxidant activity. This is the peer-reviewed version of the following article: Živković, M. B.; Matić, I. Z.; Rodić, M. V.; Novaković, I. T.; Krivokuća, A. M.; Sladić, D. M.; Krstić, N. M. Anticancer Potential of New Steroidal Thiazolidin-4-One Derivatives. Mechanisms of Cytotoxic Action and Effects on Angiogenesis in Vitro. Journal of Steroid Biochemistry and Molecular Biology 2017, 174, 72–85. [https://doi.org/10.1016/j.jsbmb.2017.07.031] Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3192]

A series of new steroidal mono- and bis(thiosemicarbazones) (2a-e and 3a-e) and corresponding mono- and bis(1,3,4-thiadiazolines) (4a-e and 5a-e) was synthesized, characterized and evaluated for their anticancer activity. Detailed NMR analysis of the mono-and bis(thiosemicarbazones) revealed the presence of two stereoisomers (Z and E) with different configurations in the hydrazone moiety at the C-3 position, where the substituents on the C(3)]=N double bond in the main isomers adopted the E configuration. The configurations at C-3 and C-17 in thiadiazolines 4a-e and 5a-e were deduced by detailed NMR analysis as well as by the examination of Dreiding molecular models and X-ray analysis of 3-thiadiazoline 4a, which confirmed the structure and absolute configuration at C-3. The synthesized compounds were tested against six cancer cell lines (HeLa, K562, MDA-MB-361, MDA-MB-453, LS174 and A549), the normal human cell line MRC-5 and peripheral blood mononuclear cells (PBMC) isolated from healthy donors. The best activity was exhibited by 3-thiosemicarbazones 2a, 2b, 2c and 2e and 3,17-bis(thiadiazolines) 5a and 5d. Examination of the mechanisms of cytotoxicity on cervical adenocarcinoma HeLa cells revealed the pro-apoptotic action of these compounds, which triggered both extrinsic and intrinsic apoptotic pathways. These compounds also showed the ability to decrease angiogenesis in vitro. In addition, 3,17-bis(thiadiazolines) 5a and 5d showed high selectivity in anticancer activity against all the examined malignant cell lines. Compound 5a displayed prominent anticancer potential. The tested compounds showed poor antimicrobial activity. Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3645]

Screens of antioxidant activity (AA) of various natural products have been a focus of the research community worldwide. This work aimed to differentiate selected samples of Merlot wines originated from Montenegro, with regard to phenolic profile and antioxidant capacity studied by survival rate, total sulfhydryl groups and activities of glutathione peroxidase (GPx), glutathione reductase and catalase in H2O2&ndash, stressed Saccharomyces cerevisiae cells. In this study, DPPH assay was also performed. Higher total phenolic content leads to an enhanced AA under both conditions. The same trend was observed for catechin and gallic acid, the most abundant phenolics in the examined wine samples. Finally, the findings of an Artificial Neural Network (ANN) model were in a good agreement (r2 = 0.978) with the experimental data. All tested samples exhibited a protective effect in H2O2&ndash, stressed yeast cells. Pre-treatment with examined wines increased survival in H2O2&ndash, stressed cells and shifted antioxidative defense towards GPx&ndash, mediated defense. Finally, sensitivity analysis of obtained ANN model highlights the complexity of the impact that variations in the concentrations of specific phenolic components have on the antioxidant defense system.

The quinone avarone, isolated from the marine sponge Dysidea avara, possesses the ability to chemically modify proteins. In this work, modification of lectin isolated from the coral Gerardia savaglia by avarone was examined. The techniques used for studying the modification were: SDS PAGE, isoelectric focusing and hemagglutination testing. The results of the SDS PAGE indicate dimerization of the protein. A shift of the pI toward lower value occurs upon modification. The change of the hemagglutination activity of the protein confirms that chemical modification of G. savaglia lectin by avarone changes its ability to interact with the membrane of erythrocytes.

Antimicrobial activity of fourteen diarylheptanoids isolated from the bark of black and green alder against twelve bacterial species (five Gram-positive and seven Gram-negative) and eight fungal strains has been reported. The most sensitive bacterial species were Klebsiella pneumoniae and Pseudomonas aeruginosa (Gramnegative), and Streptosporangium longisporum and Bacillus subtilis (Gram-positive). Among fungal strains the most sensitive to the diarylheptanoids were Fusarium equiseti, F. tricinctum, Candida albicans, and Saccharomyces cerevisiae. Oregonin (8), platyphyllenone (13), hirsutenone (14), (5S)-5-hydroxy-1,7-bis(4-hydroxyphenyl)heptan-3-one-5-O-beta-D-apiofuranosyl(1 - gt 6)-beta-D-glucopyranoside (2), and platyphylloside (1) were the most active diarylheptanoids against both bacteria and fungi, especially against fungi. Eleven of fourteen investigated diarylheptanoids exhibited stronger antifungal activity than standards nystatin and fluconazole against C. albicans and eight against S. cerevisiae. Structure/activity analysis revealed the importance of the enone moiety in the structure of diarylheptanoids for the antifungal activity. Significant antifungal activity and high content of oregonin (8) and hirsutenone (14) in the black alder bark chloroform/methanol (1:1) extract recommend the use of these compounds as easily accessible potential antifungal remedies.

A series of eighteen derivatives of marine sesquiterpene quinone avarone and its model system tert-butylquinone with amino acids has been synthesized by nucleophilic addition of amino acids to the quinones. In vitro cytotoxic activity toward human cancer cell lines (HeLa, A549, Fem-X, 1(562, MDA-MB-453) and normal MRC-5 cell line was determined. Several compounds showed very strong inhibitory activity with IC50 values less than 10 mu M. Avarone derivatives were more active than the corresponding tert-butylquinone derivatives. The results of the cytofluorimetric analysis of cell cycle of HeLa cells showed that apoptosis might be one of possible mechanism of action of these compounds in cancer cells. In order to examine the influence of caspases on cell death, the apoptotic mechanisms induced by the tested compounds were determined using specific caspases 3, 8 and 9 inhibitors. For all compounds antibacterial activities against six strains of Gram-positive and four strains of Gram-negative bacteria were determined, as well as antifungal activity against three fungal species. This is the peer-reviewed version of the following article: Vilipić, J.; Novaković, I.; Stanojković, T.; Matić, I.; Šegan, D.; Kljajić, Z.; Sladić, D. Synthesis and Biological Activity of Amino Acid Derivatives of Avarone and Its Model Compound. Bioorganic and Medicinal Chemistry 2015, 23 (21), 6930–6942. [https://doi.org/10.1016/j.bmc.2015.09.044] Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3439]

Amyloglucosidase from A. niger was covalently immobilized onto poly(GMA-co-EGDMA) by the glutaraldehyde and periodate method. The immobilization of amyloglucosidase after periodate oxidation gave a preparate with the highest specific activity reported so far on similar polymers. The obtained immobilized preparates show the same pH optimum, but a higher temperature optimum compared with the soluble enzyme. The kinetic parameters for the hydrolysis of soluble starch by free and both immobilized enzymes were determined. Amiloglukozidaza iz A.niger je imobilizovana na poly(GMA-co-EGDMA) glutaraldehidnom i perjodatnom metodom. Imobilizacija amiloglukozidaze nakon perjodatne oksidacije daje preparat sa najvećom do sada objavljenom specifičnom aktivnosti na sličnim polimerima. Dobijeni imobilizovani preparat ima isti pH optimum ali povećani termooptimum u poređenju sa rastvornim enzimom. Određeni su i kinetički parametri za hidrolizu rastvornog skroba imobilizovanim kao i rastvornim enzimom.

The avarone/avarol quinone/hydroquinone couple shows considerable antitumor activity. In this work, covalent modification of ?-lactoglobulin by avarone and its derivatives as well as by the synthetic steroidal quinone 2,5(10)-estradiene- 1,4,17-trione and its derivatives were studied. The techniques for studying chemical modification of ?-lactoglobulin by quinones were: UV/Vis spectrophotometry, SDS PAGE and isoelectrofocusing. SDS PAGE results suggest that polymerization of the protein occurs. It could be seen that the protein of 18 kD gives the bands of 20 kD, 36 kD, 40 kD, 45 kD, 64 kD and 128 kD depending on modification agent. The shift of the pI of the protein (5.4) upon modification toward lower values (from pI 5.0 to 5.3) indicated that lysine amino groups are the principal site of the reaction of ?-lactoglobulin with the quinones.

The regioselectivity of the reaction of conjugate addition of thiols amines, methanol and hydrogen chloride with the monoalkyl-1,4-benzoquinones avarone and 2-tert-butyl- 1,4-benzoquinone was investigated. It was shown that the regioselectivity of the reaction is influenced by the electrophilicity of position 5 in unprotonated 2-alkylquinones, the increased electrophilicity of position 6 in acidic medium, and by the acidity of the intermediate hydroquinones.

A conjugate of lysozyme with avarone, a bioactive sesquiterpene quinone of marine origin, and its three derivatives were synthesized. MALDI TOF mass spectral analysis and tryptic digestion showed that the only residue in lysozyme that was modified by all derivatives was lysine 97. The identity of the residue was in full correlation with the prediction obtained by molecular modeling. All bioconjugates preserved most of the enzymatic activity of lysozyme. The melting point of the conjugates was slightly increased in comparison to lysozyme, indicating a slight stabilization of structure. The antibacterial activity of all the conjugates to both Gram positive and Gram negative bacteria was stronger than the activity of either lysozyme or the quinones, the MIC values being in low micromolar range for some conjugates. This is the peer-reviewed version of the article: Novaković, I., Anđelković, U., Zlatović, M., Gašić, M.J., Sladić, D., 2012. Bioconjugate of Lysozyme and the Antibacterial Marine Sesquiterpene Quinone Avarone and Its Derivatives. Bioconjugate Chem. 23, 57–65. [https://doi.org/10.1021/bc200330m]

The sesquiterpene hydroquinone avarol (1) was isolated from the marine sponge Dysidea avara, whereas the corresponding quinone, avarone (2), was obtained by oxidation of avarol, and the significantly more lipophilic compounds [3’-(p-chloro-phenyl)avarone (3), 3’,4’-ethylenedithioavarone (4), 4’-isopropylthioavarone (5), 4’-tert-butylthioavarone (6), 4’-propylthioavarone (7), 4’-octylthioavarone (8)] were obtained by nucleophilic addition of thiols or p-chloroaniline to avarone. All these compounds were tested, at concentrations ranging from 0.5 to 50 μg/mL, for their effect on the settlement of the cyprid stage of Balanus amphitrite, for toxicity to both nauplii and cyprids and for their growth inhibitory activity on marine bacteria (Cobetia marina, Marinobacterium stanieri, Vibrio fischeri and Pseudoalteromonas haloplanktis) and marine fungi (Halosphaeriopsis mediosetigera, Asteromyces cruciatus, Lulworthia uniseptata and Monodictys pelagica).