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The molecular structures of six neutral copper(II) complexes with propylenediamine bridges and different terminal groups have been reported and evaluated. Different antioxidant tests were performed on these complexes. Additionally, the antibacterial and antifungal activities of the investigated compounds were assessed. The study was complemented with data on their interaction with human serum albumin (HSA) and evaluated using spectroscopic fluorescence techniques. The copper(II) complexes were found to bind to HSA at multiple sites (n = 0.82–1.72), displaying relatively high binding constants on the order of Ka = (4.8–8.8) × 104 M−1. Furthermore, binding constants calculated from microscale thermophoresis (MST) data were within the range of 1.27 × 104–1.13 × 105 M−1; these results correlated well with the above Ka values obtained by fluorimetry. Molecular docking simulations were employed to study the ability of the complexes to bind to target macromolecules, such as HSA and DNA. As a significant addition to understanding their biological behavior, an MTT assay was performed to investigate the cytotoxicity of the complexes. The antiproliferative activity of the investigated copper(II) complexes with propylenediamine ligands, along with cisplatin as a reference compound, was evaluated in two human cancer cell lines (LS-174 and MCF-7) and one normal cell line (MRC-5). The obtained results are discussed, providing the structure–activity relationship of the copper(II) complexes with Schiff base tetradentate ligands.

In order to discover new anticancer drugs, novel ruthenium(III) complexes [Ru(L)Cl(H2O)], where L is tetradentate Schiff base bis(acetylacetone)ethylendiimine (acacen, 1), bis(benzoylacetone)ethylendiimine (bzacen, 2), (acetylacetone)(benzoylaceton)ethylendiimine (acacbzacen, 3), bis(acetylacetone)propylendiimine (acacpn, 4), bis(benzoylacetone)propylendiimine (bzacpn, 5) or (acetylacetone)(benzoylaceton)propylendiimine (acacbzacpn, 6), were synthesized. The complexes 1 – 6 were characterized by elemental analysis, molar conductometry, and by various spectroscopic techniques, such as UV–Vis, IR, EPR, and ESI-MS. Based on in vitro DNA/BSA experiments, complexes 2 (bzacen) and 5 (bzacpn) with two aromatic rings showed the highest DNA/BSA-activity, suggesting that the presence of the aromatic ring on the tetradentate Schiff base ligand contributes to increased activity. Moreover, these two compounds showed the highest cytotoxic effects toward human, A549 and murine LLC1 lung cancer cells. These complexes altered the ratio of anti- and pro-apoptotic molecules and induced apoptosis of A549 cells. Further, complexes 2 and 5 reduced the percentage of Mcl1 and Bcl2 expressing LLC1 cells, induced their apoptotic death and exerted an antiproliferative effect against LLC1. Finally, complex 5 reduced the volume of mouse primary heterotopic Lewis lung cancer, while complex 2 reduced the incidence and mean number of metastases per lung. Additionally, molecular docking with DNA revealed that the reduced number of aromatic rings or their absence causes lower intercalative properties of the complexes in order: 2 > 5 > 6 > 3 > 4 > 1. It was observed that conventional hydrogen bonds and hydrophobic interactions contribute to the stabilization of the structures of complex-DNA. A molecular docking study with BSA revealed a predominance of 1 – 6 in binding affinity to the active site III, a third D-shaped hydrophobic pocket within subdomain IB.

The influences of the application of mono- and two-component organic modifiers on lipophilicity determination of 12 tetradentate Schiff bases by reversed-phase thin layer chromatography were investigated. The main goal is to estimate types of interaction between observed compounds and components of the applied chromatographic systems and establish some behaviour pattern in order to easier choose a combination of organic modifiers which will simulate interaction in biological systems based on the facts that the same basic intermolecular interactions are responsible for the behaviour of substances in both the biological and chromatographic system. The applied organic modifier shows the ability to modify the surface of the applied sorbent, which affects the manifestation of lipophilicity of the observed compounds. Mono-component organic modifiers from different groups of the Snyder triangle were used, as well as their two-component mixtures. In addition, we compared experimentally determined calculated parameters of lipophilicity.

Aflatoxin B1 (AFB1), is a naturally hazardous environmental contaminant, contained mainly in various cereal seeds. The maize (Zea mays L.) seeds containing various levels of the AFB1 was investigated using optical and electron paramagnetic resonance spectroscopies. The changes of lignin content and organic free radicals as indicators of the seeds' defense response to the AFB1-stressor were estimated, in the seeds' inner and outer fractions. The lignin content was determined using the Acetyl Bromide method. No correlation was found between the lignin content and the AFB1 concentration in the inner fraction (R of 0.030, p = 0.943), while a significant positive linear correlation (R of 0.9923, p= 0.00005) between the lignin content and the AFB1 concentration in the outer fraction was obtained. Employing electron paramagnetic resonance (EPR) spectroscopy, the different response of the fractions was observed, regarding the content of free radicals with increasing AFB1 concentrations. In addition, front-face fluorescence spectroscopy in combination with the deconvolution showed a positive linear correlation between the ratio of the green and blue spectral emission components (C4/C2) area and the AFB1 concentration in the outer fraction. Thus lignin content and the (C4/C2) area ratio may be reliable indicators for the screening of lignin changes related to the level of AFB1 in the seeds.

Graphite furnace atomic absorption spectroscopy (GFAAS) was applied to identification of historical pigments. The method is adapted to determine different metals, usually found in pigments. Operating conditions were optimized, such as sample drying step, pyrolysis and atomization temperatures, modifiers, and volume of sample introduced into the atomizer, to reduce interferences due to a complex sample matrix. Using the optimized method pigments in samples from the painting Coronation of the Virgin from the Church of the Shroud of the Holy Virgin in Barič were identified. The samples were analyzed also by Raman microscopy to verify the identification achieved by GFAAS. Raman microscopy confirmed the assumptionsmade based on GFAAS results. Using the two techniques a variety of pigments have been identified, such as calcite, leadwhite, goethite, hematite, ultramarine, vermilion, minium, carbon black. Based on GFAAS results the presence of azuritewas observed in the blue paint sample, although this finding was not confirmed by Raman microscopy.

This study presents a detailed characterization of 27 honey samples from the Tara Mountain region in Serbia using different comprehensive techniques and methods. The types of the honey samples were defined as monofloral (4 samples), honeydew (5 samples) and polyfloral (18 samples) honey based on determined polyphenol content, antioxidant activity, electrical conductivity and melissopalynological analyses. Physicochemical parameters such as pH (4.13–4.94), diastase activity (24.20–41.70 DN), acidity (14.60–29.70 meq/kg), content of 5-(hydroxymethyl)furfural (in range below 5, up to 16.90 mg/kg), sucrose (0.20–3.90 g/100 g), and moisture content (15.01–19.23%) confirmed the required quality of the honey samples. Sensory analysis revealed honey characteristics favorable to consumers. Analyses of 19 phenolic compounds using ultra-high-performance liquid chromatography with a diode-array detection and triple quadrupole mass spectrometry (UHPLC-DAD-MS/MS) revealed six phenolic acids and 13 other compounds from the group of flavonoids and their glycosides. In all the samples the highest content was determined for p-coumaric acid, followed by caffeic acid and pinocembrin. Besides total phenolic content and radical scavenging activity, antimicrobial activity was also examined. Most honey samples showed bactericidal activity against Staphylococcus aureus and bacteriostatic activity against Escherichia coli, while none of the honey samples inhibited the growth of Candida albicans. Chemometric analyses were applied for an in-depth study of the results to further evaluate the characteristics of the honey samples studied. Principal component analysis (PCA) was used for assessing the differences in physicochemical parameters, polyphenols content and antioxidant capacity between honey samples. The unrooted cluster tree was used to group the samples based on the melissopalynological analyses.

The influences of the application of mono- and two-component organic modifiers on lipophilicity determination of 12 tetradentate Schiff bases by reversed-phase thin layer chromatography were investigated. The main goal is to estimate types of interaction between observed compounds and components of the applied chromatographic systems and establish some behaviour pattern in order to easier choose a combination of organic modifiers which will simulate interaction in biological systems based on the facts that the same basic intermolecular interactions are responsible for the behaviour of substances in both the biological and chromatographic system. The applied organic modifier shows the ability to modify the surface of the applied sorbent, which affects the manifestation of lipophilicity of the observed compounds. Mono-component organic modifiers from different groups of the Snyder triangle were used, as well as their two-component mixtures. In addition, we compared experimentally determined calculated parameters of lipophilicity.

A method using modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) without clean-up step based on the sample dilution approach followed by the liquid chromatography coupled with the tandem mass spectrometry (LC-MS/MS) has been established for determination of 179 pesticide residues in cabbage and rice samples. Two different LC columns were used and their sensitivity was investigated regarding the sample volume. Evaluation of the matrix effect in context of sample dilution and applied extraction solvents was investigated. The method was validated according to Document SANTE/12682/2019. For cabbage samples, recoveries were 70–120% for concentration level of 5 μg/kg; and 70–115% for concentration level of 50 μg/kg; precision RSDr <17%; limits of detection and quantification were in the ranges of 0.4–5.5 and 1.2–16.7 μg/kg, respectively. For rice samples, recoveries were 70–109% for 10 μg/kg concentration; 70–115% for 100 μg/kg concentration; precision RSDr <14%, while limits of detection and quantification were in the ranges of 0.5–4.2 and 1.5–12.7 μg/kg, respectively.

Background: Diazepam belongs to the group of 1,4-benzodiapines. It is used for the treatment of anxiety, convulsions and as a muscle relaxant. The presence of 4,5-azomethine group enables its electrochemical detection.Introduction: A screen-printed electrode modified with antimony film was used for the determination of diazepam in pharmaceutical preparationsMethods: Electrode modification was done by ex-situ deposition of antimony on commercially available screen-printed electrode. Parameters affecting the electroanalytical response of the sensor, such as deposition potential, deposition time, and antimony concentration, were examined and optimized. The modified electrode showed enhanced electroactivity for diazepam reduction compared to unmodified electrode. Under optimal conditions, linear sweep voltammetry was used for the determination of analyte.Results: The sensor showed linear dependence in the range from 0.5 to 10 μmol/L, the correlation coefficient was 0.9992. The limit of detection was 0.33 μmol/L, corresponding limit of quantification was 1.08 μmol/L. Modification enabled determination of diazepam in the presence of oxygen. Conclusion: The modified electrode was used for the determination of diazepam in tablets. Results confirmed the applicability of the electrochemical sensor.

The study of the chemical composition of wines is nowadays a topic of great interest because of the importance of this market, especially in Italy, and also considering the numerous cases of falsification of famous and very expensive wines. The present paper focused on the analysis of metals and polyphenols in Italian wines belonging to different provenance and types. At this purpose 20 elements were quantified by inductively coupled plasma optical emission spectrometry (ICP-OES) and ICP mass spectrometry (ICP-MS). Regarding polyphenols, a total of 32 were quantified, among 6 were anthocyanins. Furthermore, in 4 samples (1 rosè and 3 red wines) 42 anthocyanins and related compounds were identified by ultra-high performance liquid chromatography (UHPLC)-Orbitrap MS technique (among these, 6 were also quantified). Non-anthocyanins were determined using UHPLC coupled with a diode array detector and triple-quadrupole mass spectrometer (UHPLC–DAD-QqQ-MS). Total phenolic content (TPC) and radical scavenging activity (RSA) were measured using spectrophotometric methods. The results obtained by elemental techniques were submitted to principal components analysis (PCA) allowing to get information on both geographical and botanical origin of the examined wine samples. Some polyphenols have been detected in higher concentrations only in a certain type of wine, as for example in the case of Grechetto wine. Most of the identified anthocyanin derivatives (pyranoanthocyanins) are formed during the aging of wine by reaction with the other wine components.

The influences of the application of mono- and two-component organic modifiers on lipophilicity determination of 12 tetradentate Schiff bases by reversed-phase thin layer chromatography were investigated. The main goal is to estimate types of interaction between observed compounds and components of the applied chromatographic systems and establish some behaviour pattern in order to easier choose a combination of organic modifiers which will simulate interaction in biological systems based on the facts that the same basic intermolecular interactions are responsible for the behaviour of substances in both the biological and chromatographic system. The applied organic modifier shows the ability to modify the surface of the applied sorbent, which affects the manifestation of lipophilicity of the observed compounds. Mono-component organic modifiers from different groups of the Snyder triangle were used, as well as their two-component mixtures. In addition, we compared experimentally determined calculated parameters of lipophilicity.

Pollutants such as pharmaceutical products and pesticides are still present in treated water. Several of these compounds are photoactive. The photodegradation of eight organic pollutants was studied using listed advanced oxidation processes: UV/H2O2, UV/persulfate, Fenton, photo-Fenton and UV/TiO2. The results show that photodegradation is most effective in the first 10 min of treatments in simulated urban wastewater collected from the local Nišava River. To identify the correlation between applied degradation processes as well as the relationship among the structure of investigated compounds and efficiency of degradation, Pearson’s correlation coefficient analysis and principal component analysis (PCA) were performed. The established correlations between the applied processes, as well as the determination of the influence of the structure on the efficiency of degradation, enable a more efficient choice of the degradation procedure, especially in the case of interference. Additionally, process electrical energy consumption and treatment costs for simulated urban wastewater with different pharmaceuticals and pesticides were determined.

Different Schiff base complexes have biological activities that make them suitable for drug design. The biological properties of tetradentate Schiff base copper(II) complexed with N,N′-bis(acetylacetone)propylenediimine have been studied. The cytotoxic activity towards Caco-2 cells were determined by MTT, Anexin V and PI apoptosis assays. N,N′-bis(acetylacetone)propylenediimine-copper(II) showed the anti-cancer and anti-proliferative properties by inducing apoptosis in Caco-2 cells. A comparison of the cytotoxic activity of this compound with cisplatin shows that it is more effective on the colorectal cancer cell line Caco-2. The binding capacity and interaction of N,N′-bis(acetylacetone)propylenediimine-copper(II) with HSA were systemically investigated by in vitro fluorescence spectroscopy, CD spectroscopy, and in silico molecular docking study. Furthermore, in vitro and in silico interaction studies indicated that the complex binds to HSA through a static quenching mechanism without changes in protein conformation. The calculated number of binding sites was in line with molecular docking studies. The obtained Ka value suggests that the compound can be released from the protein in target cells. The tetradentate Schiff base copper(II) complex exhibited in vitro biological activities against cancer epithelial cells, which depend on the molecular structure of the complex, causing apoptosis, and the complex can bind to the protein drug carrier in circulation to the target tissue.

This paper describes the determination of Pb and Cu with a Nafion-modified glassy carbon electrode and MnCo2O4 nanoparticles as working electrode for anodic stripping voltammetry. Pb and Cu were accumulated in HCl/KCl (0.1 mol dm-3) at a potential of -1.4 V (vs. Ag/AgCl electrode) for 480 s, followed by a linear sweep anodic stripping voltammetry (ASV) scan from -1.0 to +0.5 V. Under optimum conditions, the calibration curves were linear in the range of 0.01 - 8 and 0.01 - 5 mg dm-3 for Pb and Cu, respectively. Effect of sample dilution, accumulation time and potential were optimized. A study of interfering substances was performed. A significant increase in current was obtained at the modified electrode in comparison with the bare glassy carbon electrode. The modified electrode was successfully applied for determination of Pb and Cu in wine samples after a simple preparation procedure. Pb and Cu content in wine was used for estimation of the target hazard quotient (THQ) values for minimal and maximal levels of the metals.

A new glucose biosensor for selective and sensitive determination of glucose in beverage samples was developed. A copper complex with a Schiff base, N,N’-bis(acetylacetonato) propylenediimine, was used as a mediator. It was mixed with glucose oxidase (GOx) and prepared as carbon paste electrode (CPE). Cyclic voltammetry was used for electrochemical measurements. The biosensor showed improved sensitivity when enzyme mediator ratio was 1 : 5, and working pH was 6.6 in 0.1 M phosphate buffer. The linear response of the biosensor for glucose concentration was in the range from 0.5 to 10 mM, with low detection limit of 0.36 mM (calculated as 3 s/n) and sensitivity of 0.16 μA/mM. The reproducibility of the biosensor, calculated as relative standard deviation, was 1.9% for 6 intra-day measurements. Biosensor was stored at +4 °C between experiments, and it was stable during 14 days after the preparation. The developed biosensor was applied on determination of glucose in commercial beverages (apple and cherry juice) and obtained results showed good agreement with the reference method.

BACKGROUND: Cereal seeds, such as maize seeds, are frequently contaminated with aflatoxin B1 (AFB1), one of the most dangerous naturally occurring carcinogens. In plants, phenolamides are involved in biotic stress response. The data on variations of phenolamides in AFB1-containing seeds are limited. RESULTS: Five polyamine conjugates, including two spermidine and three putrescine conjugates, were tentatively identified in methanolic extracts, using HPLC-DAD-MS. The ratio of putrescine to spermidine conjugates changed with increasing AFB1 concentration in a logistic dose–response manner, with a ratio of below 1 up to a concentration of 51.51 μg kg−1, and approximately 2.54 and 3 at higher concentrations of 177.4 and 308.13 μg kg−1, respectively. The observed variations of the total antioxidant activity and the total phenolic content may support this biphasic behaviour of the seeds against AFB1 stress. CONCLUSIONS: The obtained data are a contribution to the understanding of the roles of polyamine conjugates in seed defence to increasing AFB1 concentrations. According to our knowledge, this study reports for the first time the biphasic response of maize seeds to increasing AFB1 contamination level, comprising the induction of polyamine conjugate accumulation and variation in the ratio of conjugates. This dose–response relationship may provide useful information in the field of agricultural and food chemistry as an indicator of AFB1 contamination level and, hence, for selecting an appropriate seed quality.

The research subject of this paper was a detail physicochemical analysis of 28 honey samples from the northern part of Montenegro. The honey from Montenegro has not been previously studied in such detail. Differentiation between samples, such as honeydew honey and polyfloral honey, was based on electrical conductivity, which was higher than 0.8 mS cm-1 for honeydew honey, as was expected. Other investigated physicochemical parameters (water content, free acids, diastase activity, hydroxymethylfurfural (HMF) content and sugar content) have shown great similarity for all honey samples. The main interest of this study was the identification and quantification of phenolic compounds using ultra-high performance liquid chromatography (UHPLC) with mass spectrometry detection. The results show that honey samples are very rich in phenolic compounds, especially quercetin. Among the 31 quantified phenolic compounds, the most dominant were phenolic acids. The highlight was based on p-hydroxybenzoic acid, p-coumaric acid, caffeic acid and ferulic acid. Considering polyphenolic compounds and sugar content, a high nutritional value can be observed in all samples, with an emphasis on polyfloral honeys, as was confirmed with principal component analysis (PCA). In addition, all honey samples were tested for total phenolic content (TPC) and radical scavenging activity (RSA). The results indicate the higher antioxidant ability of honeys from Montenegro in comparison to some honey samples from other countries in the region.

Glukoza-oksidaza (GOx) je vaţan industrijski enzim koji se predominantno koristi kao biokatalizator u industriji hrane za proizvodnju glukonske kiseline, uklanjanje kiseonika i sterilizaciju. U farmaceutskoj industriji i kliničkoj biohemiji se koristi kao biosenzor za određivanje koncentracije glukoze, dok postoje pokušaji da se iskoristi i za proizvodnju biogorivnih ćelija koje proizvode električnu energiju koristeći glukozu i kiseonik iz ljudske krvi u okvirima nanobiotehnologije. Za rasprostranjeniju primenu GOx neophodno je unaprediti neke od njenih osobina kao što su aktivnost, pH optimum, reaktivnost sa kiseonikom i stabilnost. Jedna od metoda kojom se unapređuju proteini je dirigovana evolucija. Ova metoda podrazumeva iterativne tehnike generisanja biblioteka proteinskih mutanata (ili varijanti) i selekciju proteina sa odgovarajućom ţeljenom funkcijom iz ovih biblioteka.U cilju pronalaţenja mutanata GOx iz Aspergillus niger koji su oksidativno stabilniji i aktivniji, u ovom radu su razvijene dve metode pretraţivanja bazirane na ekspresiji proteina na površini ćelija kvasca. Pored razvoja metoda pretraţivanja ispitivana je i optimizacija ekspresije rekombinantne GOx u kvascu Pichia pastoris za heterolognu ekspresiju mutanata GOx i njihovu kinetičku karakterizaciju.Oksidacija bočnih ostataka amino kiselina je jedan od glavnih razloga nestabilnosti nativne trodimenzionalne strukture GOx. Posebno osetljiv prema oksidaciji je metionin, koji se prevodi u metionin-sulfoksid čak i pod blagim uslovima u prisustvu kiseonika i kiseoničnih reaktivnih vrsta kao što su vodonik-peroksid, superoksid anjon radikal i drugi. Da bi utvrdili uticajpozicije metionina na oksidativnu stabilnost GOx, svih 11 metionina je razmatrano za mesto specifičnu mutagenezu..., Glucose-oxidase (GOx) is an important industrial enzyme that is predominantly used as a biocatalyst in the food industry for the production of gluconic acid, oxygen removal and sterilization. In the pharmaceutical industry and clinical biochemistry it is used as a biosensor for determining glucose concentration, while there are attempts to utilize it in the production of biofuel cells that produce electricity using glucose and oxygen from human blood within the framework of nanobiotechnology. For the widespread use of GOx it is necessary to improve some of its properties such as activity, pH optimum, reactivity with oxygen and stability. One of the methods for improving proteins is directed evolution. This method involves iterative techniques for generating libraries of protein mutants (or variants) and selecting proteins with the desired function from these libraries.In order to find GOx mutants from Aspergillus niger that are oxidatively more stable and active, in this work two methods of screening based on protein expression on the surface of yeast cells have been developed. In addition to the development of the screening methods, the optimization of the expression of recombinant GOx in yeast Pichia pastoris for heterologous expression of GOx mutants and their kinetic characterization was studied.Aminoacid side chain oxidation is one of the main causes for structural instability of native tridimensional structure of GOx. Particularly sensitive to oxidation is methionine residue, which is converted to methionine sulfoxide even under mild conditions in the presence of oxygen and oxygen reactive species such as hydrogen peroxide, superoxide anion radical and others. In order to determine the effect of the position of the methionine amino acidresidue on the oxidative stability of GOx, all 11 methionines were considered for site directed mutagenesis...

Šifove baze i njihovi kompleksi pokazuju različitu biološku aktivnost poput antiviralne, antimikrobne, antimalarijske i antikancerske. Zbog činjenice da biološka aktivnost jedinjenja zavisi prvenstveno od lipofilnosti molekula, što je posledica strukture jedinjenja, određivanje i korelacija lipofilnosti sa hemijskom strukturom, kao i određivanje biološke aktivnosti su postali nezaobilazni u sintezi novih lekova..., Schiff bases and their complexes are versatile compounds which have various biological activities such as antiviral, antimicrobial, antimalarial, and anticancer activity. Biological activity of compounds depends on their molecular structure, especially lipophilic character. Determination of lipophilicity, its correlation with chemical structure, and biological activity is very important in drug design...

The is work presents the development of a flow injection system for differential pulse amperometry (DPA) for diazepam determination in the presence of oxygen. The thin flow cell consisted of the bare glassy carbon electrode, reference silver/silver chloride, and stainless steel as the auxiliary electrode. Electrochemical reduction of diazepam (DZP) was characterised by cyclic voltammetry. Azomethine reduction peak was used for DZP quantification. The detector response was linear in the range 20-250 mu mol/dm(3) of diazepam, with a calculated detection limit of 3.83 mu g/cm(3). Intraday and interday precision were 1.53 and 10.8%, respectively. The method was applied on three beverage samples, energetic drink, and two different beer samples, and obtained recoveries were from 93.65 up to 104.96%. The throughoutput of the method was up to 90 analyses per hour.

Cilj ove doktorske disertacije bio je razvoj metodologije za identifikaciju proteina uuzorcima kulturnog nasleđa koja uključuje primenu masene spektrometrije i bioinformatike.Predloženi postupak je veoma jednostavan i ne zahteva celovitost molekula proteina radipouzdane identifikacije. Nakon hidrolize tripsinom, peptidi su analizirani primenom MALDITOFmasene spektrometrije uz podršku MALDI-TOF/TOF, kao i ESI tandem masenespektrometrije na LTQ-Orbitrap XL instrumentu. Proteini su identifikovani na osnovugenerisanih spektara uz pomoć bioinformatičkih alata.U prvom delu disertacije primenjen je PMF pristup baziran na MALDI-TOF masenojspektrometriji, ali snimljeni su i tandem maseni spektri najintenzivnijih pikova peptidaprimenom MALDI-TOF/TOF analizatora, na osnovu kojih su identifikovane sekvenceaminokiselina u peptidima. Tandem masena spektrometrija pruža uvid ne samo u odnos mase inaelektrisanja peptida, već i u njegovu fragmentaciju koja je visoko specifična. Na taj načinmoguća je nedvosmislena identifikacija proteina u kompleksnim smešama, čak i izneočekivanih izvora – pod uslovom da su ti proteini sekvencirani i da se nalaze u bazi podataka.Analiziran je set referentnih proteinskih materijala koji su tradicionalno korišćeni za slikanjetehnikom tempera. Pre primene postupka na analizu uzoraka starih slika, analizirani su i modeluzorci kako bi se procenio uticaj pigmenata na uspešnost analize. U analiziranm uzorcimapravoslavnih ikona identifikovani su peptidi kolagena, najverovatnije iz slikarske podloge, kojase tradicionalno pravi od krede ili gipsa i tutkala.Primena tandem masene spektrometrije u analizi proteina, ipak, najčešće podrazumevaprimenu tečne hromatografije kuplovane sa jednim ili više masenih analizatora. U drugom deluove doktorske disertacije uzorci su analizirani pomoću LTQ-Orbitrap XL masenogspektrometra uz prethodno reversno-fazno hromatografsko razdvajanje. Metoda jeoptimizovana na referentnim i model uzorcima, nakon čega su analizirane mikro kol, The aim of this doctoral dissertation was development of a methodology foridentification of proteins in cultural heritage samples, that includes application of massspectrometry and bioinformatics. The suggested protocol is very simple and the integrity of theprotein molecule is not required for the reliable identification. After tripsin hydrolysis, thepeptides are analyzed by MALDI-TOF mass spectrometry, supported by MALDI-TOF/TOF,as well as ESI tandem mass spectrometry on LTQ-Orbitrap XL instrument. Proteins areidentified with the help of bioinformatic tools, on the basis of the spectra generated.In the first part of this dissertation the PMF approach is applied, based on MALDITOFmass spectrometry, but also, tandem mass spectra of the most intense peptide peaks arecollected on MALDI-TOF/TOF mass analyzer, that enabled identification of peptidesequences. Tandem mass spectrometry provides insight not only in the m/z ratio of peptides,but also in the specific pattern of peptide fragmentation. That way is enabled undoubted proteinidentification in complex mixtures, even from unexpected sources, if given proteins aresequenced and present in a sequence database. A set of reference proteinaceous materials,traditionally used in tempera technique of painting, are analyzed here. Before applying theprocedure for analysis of historical paintings, a number of mock samples are analyzed in orderto estimate the influence of pigments on the analysis outcome. Peptides of different collagenchains are identified in analyzed samples of orthodox icons. The collagen is usually present inthe ground layer of paintings, that is traditionally made of chalk or gypsum and animal glue.Application of tandem mass spectrometry in protein analysis usually involvescombination of liquid chromatography and one or more mass analyzers. In the second part ofthis dissertation samples are analyzed on LTQ-Orbitrap XL mass spectrometer afterchromatographic separation on a reverse phase column. The method is

The objectives of this study were to gain insights into structure-retention relationships and to propose the model to estimating their retention. Chromatographic investigation of series of 36 Schiff bases and their copper(II) and nickel(II) complexes was performed under both normaland reverse-phase conditions. Chemical structures of the compounds were characterized by molecular descriptors which are calculated from the structure and related to the chromatographic retention parameters by multiple linear regression analysis. Effects of chelation on retention parameters of investigated compounds, under normal-and reverse-phase chromatographic conditions, were analyzed by principal component analysis, quantitative structure-retention relationship and quantitative structure-activity relationship models were developed on the basis of theoretical molecular descriptors, calculated exclusively from molecular structure, and parameters of retention and lipophilicity.