Biological studies of organoselenium trans-palladium(II) complexes

In this work, two complexes of trans-palladium(II) with organoselenium compounds as their ligands were investigated., PdSe1, [Pd(L1)2Cl2], (L1 = 5- (phenylselanylmethyl) -dihydrofuran-2 (3H) -one)) and PdSe3, [Pd(L3)2Cl2], (L3 =2,2-dimethyl-3-(phenylselanylmethyl)-tetrahydro-2H-pyran). Their antimicrobial and antioxidant activity as well as the effect of the formed biofilm of selected bacteria were studied. Antimicrobial activity was tested by determining the minimum inhibitory concentrations (MIC) and minimum microbicidal concentration (MMC) using the resazurin microdilution plate method The effect of complexes and ligands on formed biofilm of S. aureus ATCC 25923, S. aureus, and P. aeruginosa was determined. The in vitro antioxidant activity of the complex was determined based on the neutralizing capacity of DPPH radicals expressed as EK50. The investigated complexes showed significantly higher antimicrobial activity than the corresponding ligands. The most significant activity was shown on Pseudomonas aeruginosa. Complexes showed a lower effect on tested bacterias formed biofilm than the tested ligands. Complex Pd-Se1 showed a better effect on the tested biofilm of S. aureus, while complex Pd-Se3 showed a significant effect on the tested biofilm of P. aeruginosa. The antioxidant activity of all n organoselenium trans-palladium(II) complexes is significant, with the PdSe1 complex being more active. These complexes have the potential to be further investigated as metallodrugs.The authors are grateful to the Ministry of Education, Science and Technological Development of the Republic of Serbia (Agreement No 451 03 9 2021 14 200378 451 03 68 2021 14 200122 and Agreement No 451 03 68 2021 14 200378 for financial suppor

Response of selected microbial strains and their consortia to the presence of automobile paints: Biofilm growth, matrix protein content and hydrolytic enzyme activity

The goal of the current study was to examine the effects of pollutants (White color – CP; Metallic red color – FM; Thinner – CN; Thinner for rinsing paint – MF; Basic color (primer) – FH) originating from the automotive industry on the biofilm growth, matrix protein content, and activity of the hydrolytic enzymes of selected microbial strains in laboratory conditions that mimic the bioreactor conditions. The chosen microorganisms (bacteria, yeasts, and fungi) were isolated from automotive industry wastewater. Pure microbe cultures and their consortia were injected into AMB Media carriers and developed into biofilms. The use of AMB media carriers has been linked to an increase in the active surface area colonized by microorganisms. Afterwards, the carriers were transferred to Erlenmeyer flasks with nutrient media and pollutants at a concentration of 200 μL/mL. The current study found that, depending on the microbial strain, development phase, and chemical structure, the assessed pollutants had an inhibitory or stimulatory influence on the growth of single cultures and their consortia. Statistical analysis found positive correlations between the protein content in the matrix and the biofilm biomass of Rhodotorula mucilaginosa and consortia in CP and FH media, respectively. The proteolytic activity of Candida utilis was very pronounced in media with MF and CN. The best alkaline phosphatase activity (ALP) was achieved in the CN medium of R. mucilaginosa. Acid invertase activity was the highest in the FM and CP media of Escherichia coli and consortia, respectively, whereas the highest alkaline invertase activity was measured in the MF medium of E. coli. A positive correlation was confirmed between ALP and the biofilm biomass of R. mucilaginosa in CP and CN media, as well as between ALP and the biofilm biomass of Penicillium expansum in FM medium. The findings provide novel insights into the extracellular hydrolytic activity of the investigated microbial strains in the presence of auto paints, as well as a good platform for subsequent research into comprehensive biofilm profiling using modern methodologies

The volume of postmortem bleeding in drowning victims having sustained blunt thoracic aortic injury resulting from vehicular accidents

Abstract: Recent studies have shown that 1500 mL of blood found in the intrapleural cavity due to blunt thoracic aortic injuries, should be considered as postmortem in the cases of immediate deaths. Considering that drowning lasts for 4 to 5 minutes, the question is about if that time period has an influence to the volume of antemortem exsanguinated blood if accompanied with aortic rupture. A retrospective study determined two groups out of which the first one consisted of vehicle occupants who fell in the river canyon and died from drowning accompanied by traumatic aortic rupture. The second group was comprised of vehicle occupants injured in conventional vehicle accidents where the occupants died from bleeding due to aortic rupture. The ROC curve is used to evaluate the cut-off value related to the volume of postmortem bleeding originating from aortic rupture and total exsanguinated blood. The study showed that the time elapsed during drowning did not significantly influence the volume of antemortem and postmortem blood. In cases of the blunt thoracic aortic injury with concomitant drowning as cause of death, volumes less than 1400 mL of intrapleural bleeding should be considered as mostly postmortem. Key Words: aortic rupture, bleeding, canyon death, drowning, postmortem bleeding. 1) Department of Forensic Early work

Prinos i kvalitet klonova sorte Kaberne Sovinjon u Niškom rejonu

In terms of Nis regions in 2009-2010. The questioned the yield and quality of grape clones of Cabernet Sauvignon (clon 169) and (clone 685). Between tests ruled favorable conditions for the expression of biological and technological properties of the tested clones. Yields of grapes and its variation by years show high and stable fertility tested clones. Most of sugar content varied from 19.95% to 20.05% in the examined clones, while the variety of the standard achieved slightly higher sugar content (23%). Total acid ranged from 7.6g/l to 8.9 g/l. Test results confirm the importance of growing clones of Cabernet Sauvignon in conditions of low wine-growing region.U radu se prikazuju rezultati ispitivanja klonova sorte Kaberne Sovinjon (klon 169 i klon 685) koji su dobijeni iz Francuske u cilju ispitivanja i eventualne valorizacije za uslove našeg vinogradarstva. U uslovima niškog vinogradarskog rejona ispitivani klonovi su ispoljili značajne razlike u ostvarenom prinosu i kvalitetu grožđa, što ukazuje na njihov različiti biološki potencijal rodnosti

YIELD AND QUALITY OF MÜLLER-THURGAU CLONE GM11 OF NIS GRAPE GROWING REGION

This paper presents the results of research variety Müller-Thurgau, clone 11 Gm, in order to determine quality indicators and the possibility of expansion in the vineyards of Southern Serbia. In terms of Nis grape growing region of the test are the most important agro technological and economic characteristics of the clone 11 Gm compared to the standard variety Müller-Thurgau. The test clone exhibited significant differences in yield and quality of grapes

Developing Teaching Competencies for Implementing Blended Learning in Higher Education: Experiences of Faculty of Science, University of Kragujevac

Part of this work was supported by ERASMUS+ funds (Strengthening Teaching Competencies in Higher Education in Natural and Mathematical Sciences, grant contract 2018-2467/001-001).Publishe

THE CHARACTERISTICS OF FRUITFULNESS OF SOME INTERSPECIES GRAPEVINE CULTIVARS

The results of important agro-biological and technological characteristics of three grapevine interspecies cultivars (Medina, Gecej Zamatos, and Kristala) are presented in this study. The following parameters were monitored: the total number of developed shoots, the number of fertile shoots, the number of bunch per vine, grape yield, fertility coefficient, the average bunch weight, yield per hectare, bunch and berry structural indicators and grape quality expressed through the content of sugar in must. Statistically significant differences were determined between the examined varieties regarding following characteristics: the number and yield of bunches per vine, structural indicators of berries and sugar content in must. The analysis of the obtained results related with the analyzed grape varieties in the agro-ecological conditions of Northern Bosnia showed that those varieties can successfully be cultivated in similar or identical agro-ecological conditions

Heavy metal tolerance and removal efficiency of the Rhodotorula mucilaginosa and Saccharomyces boulardii planktonic cells and biofilm

The impact of heavy metals, cadmium (Cd2+), zinc (Zn2+) and nickel (Ni2+) on planktonic cells and biofilm of Rhodotorula mucilaginosa and Saccharomyces boulardii was examined. The metal tolerance testing was performed by MBECTM-HTP assay. The minimum inhibitory concentration (MICp) and minimum lethal concentration (MLCp) were determined as well as the minimum biofilm eradication concentration (MBEC). Biofilm was more tolerant on the presence of heavy metals than the planktonic cells. The planktonic cells of R. mucilaginosa were tolerant to high concentrations of Cd2+, Zn2+ and Ni2+, while the planktonic cells of S. boulardii tolerated Zn2+, exclusively. The R. mucilaginosa biofilm was tolerant to all of the tested metal concentrations and the obtained results were confirmed by fluorescence microscopy. S. boulardii did not show ability of biofilm formation. Metal removal efficiency of the R. mucilaginosa planktonic cells and biofilm were also tested. The R. mucilaginosa biofilm showed higher efficiency in metals removing compared to the planktonic cells. Until now, the heavy metal tolerance and the removal efficiency (Cd2+, Zn2+ and Ni2+) analyzes were performed solely on planktonic cells of Rhodotorula species. In this study, we investigated the metal removal efficiency of R. mucilaginosa planktonic cells and biofilm and compared the obtained results.Publishe

Synthesis, Characterization and Biological Studies of Organoselenium trans-Palladium(II) Complexes

Background: Over the years, transition metal complexes have exhibited significant antimicrobial and antitumor activity. It all started with cisplatin discovery, but due to the large number of side effects it shows, there is a growing need to find a new metal-based compound with higher selectivity and activity on more tumors. Objectives: Two novel trans-palladium(II) complexes with organoselenium compounds as ligands, [Pd(L1)2Cl2] (L1 = 5-(phenylselanylmethyl)-dihydrofuran-2(3H)-one) and [Pd(L2)2Cl2] (L2 = 2- methyl-5-(phenylselanylmethyl)- tetrahydrofuran) were synthesized, in the text referred to as Pd-Se1 and Pd-Se2. Also, a structurally similar trans-palladium(II) complex, [Pd(L3)2Cl2] (L3= 2,2- dimethyl-3-(phenylselanylmethyl)-tetrahydro-2H-pyran ) was synthesized according to an already published work and is referred to as Pd-Se3. The interaction of synthesized complexes with DNA and bovine serum albumin was observed. Also, antimicrobial activity and in vitro testing, cell viability, and cytotoxic effects of synthesized ligands and complexes on human epithelial colorectal cancer cell line HCT-116 were studied. Molecular docking simulations were performed to understand better the binding modes of the complexes reported in this paper with DNA and BSA, as well as to comprehend their antimicrobial activity. Methods: The interactions of the synthesized complexes with DNA and bovine serum albumin were done using UV-Vis and emission spectral studies as well as docking studies. Antimicrobial activity was tested by determining the minimum inhibitory concentrations (MIC) and minimum microbicidal concentration (MMC) using the resazurin microdilution plate method. Cytotoxic activity on cancer cells was studied by MTT test. Results: The Pd(II) complexes showed a significant binding affinity for calf thymus DNA and bovine serum albumin by UV-Vis and emission spectral studies. The intensity of antimicrobial activity varied with the complexes Pd-Se1 and Pd-Se3, showing significantly higher activity than the corresponding ligand. The most significant activity was shown on Pseudomonas aeruginosa. Under standardized laboratory conditions for in vitro testing, cell viability and cytotoxic effects of synthesized ligands and complexes were studied on human epithelial colorectal cancer cell line HCT-116, where Pd-Se2 showed some significant cytotoxic effects. Conclusion: The newly synthesized complexes have the potential to be further investigated as metallodrugs.Publishe

Antimicrobial, antioxidant and DNA-binding studies of palladium(II) complexes with different chelate ligands containing nitrogen donor atoms

The antimicrobial and antioxidant activities, as well as the DNA-binding of four square-planar Pd(II) complexes, [Pd(terpy)Cl]+ (C1), [Pd(en)Cl2] (C2), [Pd(DMEAImiPr)Cl2] (C3) and [Pd(dach)Cl2] (C4) (terpy = 2,2′:6′,2′′- -terpyridine, en = ethylenediamine, dach = trans-1,2-diaminocyclohexane and DMEAImiPr = N2-((1,3-dihydro-1,3-diisopropyl-4,5-dimethyl)-2H-imidazol-2- ylidene)-N1,N1-dimethyl-1,2-ethanediamine are reported. The antimicrobial activities of the Pd(II) complexes with the appropriate ligands were tested using the microdilution method against 18 strains of microorganisms, whereby the minimal inhibitory concentration (MIC) and the minimal microbicidal concentration (MMC) were determined. The antibiofilm activity of [Pd(terpy)Cl]+ and the corresponding ligand were determined on a formed biofilm. The intensity of antimicrobial activity varied depending on the type of microorganism and the tested compound. The C1 complex with the corresponding ligand demonstrated significantly greater overall antimicrobial activity than C2, C3 and C4. The antibacterial activity of the C1 complex was better than its antifungal activity that was overall greater than that of the positive control, fluconazole. The greatest sensitivity for C1 and L1 was with Penicillium italicum (MIC < 0.49 μg mL-1) among the fungi, and with Proteus mirabilis ATCC 12453 (MIC = 0.98 μg mL-1) among the tested bacteria. The tested compounds show low and moderate antibiofilm activity. The complexes showed weak antioxidant properties when tested using the DPPH (1,1-diphenyl-2- -picrylhydrazyl) method. The interaction of the metal complexes C1–C4 with calf thymus DNA (CT-DNA) was further examined by absorption (UV–Vis) and emission spectral studies (EthBr displacement studies). Overall, the investigated complexes exhibited good DNA interaction ability.Publishe