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In this study, a series of synthesized 3-(4-substituted benzyl)-5-isopropyl-5-phenylhydantoin derivatives as a potential antiproliferative and antimigratory agents were investigated. The possible antitumor mechanisms of investigated hydantoin derivatives were examined on human breast cancer cell line MDA-MB-231. The cells were treated with different concentrations of compounds (from 0.01 µM to 100 µM) during 24 h and 72 h. The proliferation index, nitric oxide production, apoptosis rate, and migration capacity were measured. The cell invasion potential was examined by measuring the level of MMP-9 and COX-2 gene expression. All tested compounds expressed antiproliferative activity and induced dose- and time-dependent increase in the level of nitrites. The investigated molecules significantly decreased cell survival rate, migration capacity and the expression levels of genes included in the process of tumor invasion. Obtained data suggest that the tested hydantoin derivatives express considerable antitumor activity by reducing cell division rate, elevating apoptosis level, and inhibiting the motility and invasiveness of breast cancer cells. The results obtained in this study indicate that investigated compounds express potential as a novel chemotherapeutic agents against breast cancer growth and progression. Keywords: Hydantoin derivatives, Breast cancer cell line MDA-MB-231, Proliferation, Apoptosis, Cell motility, Nitric oxide

The discovery of novel biodegradable biomaterials able to support and control cellular activity as well as development of an enhanced and efficient method for their fabrication, are of paramount importance in the field of tissue engineering. This study highlights the design of novel degradable hydrogels based on gelatin and hydroxyethyl (meth)acrylates using the innovative combined two-step sequential microwave-assisted and UV photo-polymerization technique. Chemical composition, morphology, swelling capacity and degradation rate of the synthesized hydrogels were evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), swelling and weight loss measurements. As an initial step for evaluation of performance of the hydrogels in the biological environment, the in vitro biocompatibility of these hydrogels, was evaluated using L929 mouse fibroblasts. Obtained results demonstrated that the hydrogels possess a porous morphology with interconnected pores, 50% in vitro degradation after 7 months, and satisfied biocompatibility on L929 fibroblast cells. These unique performances of the hydrogels make them promising candidates for in vivo evaluation in clinical studies aiming at tissue regeneration.

Succinimides, which contain a pharmacophore responsible for anticonvulsant activity, are frequently used antiepileptic drugs and the synthesis of their new derivatives with improved efficacy and tolerability presents an important task. Nowadays, multitarget/tasking methodologies focused on quantitative-structure activity relationships (mt-QSAR/mtk-QSAR) have an important role in the rational design of drugs since they enable simultaneous prediction of several standard measures of biological activities at diverse experimental conditions and against different biological targets. Relating to this very topic, the mt-QSAR/mtk-QSAR methodology can give only binary classification models, and as such, in this study a regression mtk-QSAR (rmtk-QSAR) model based on a novel modular neural network (MNN) has been proposed. The MNN uses standard classification mtk-QSAR models as input modules, while the regression is performed by the output module. The rmtk-QSAR model has been successfully developed for the simultaneous prediction of anticonvulsant activity and neurotoxicity of succinimides, with a satisfactory accuracy in testing (R-2 = 0.87). Thus, the proposed mtk-QSAR regression method can be regarded as a viable alternative to the standard QSAR methodology.

Design of a new drug entity is usually preceded by analysis of quantitative structure activity (properties) relationships, QSA(P)R. Six newly synthesized succinimide derivatives have been determined for (i) in silico physico-chemical descriptors, pharmacokinetic and toxicity predictors, (ii) in vitro biological activity on four different carcinoma cell lines and on normal fetal lung cells and (iii) lipophilicity on liquid chromatography. All compounds observed were predicted for good permeability and solubility, good oral absorption rate and moderate volume of distribution as well as for modest blood brain permeation, followed by acceptable observed toxicity. In silico determined lipophilicity, permeability through jejunum and aqueous solubility were correlated with experimentally obtained lipophilic constants (by use of high pressure liquid chromatography) and linear correlations were obtained. Absorption rate and volume of distribution were predicted by chromatographic lipophilicity measurements while permeation through blood bran barrier was predicted dominantly by molecular size defined with molecular weight. Five compounds have demonstrated antiproliferative activity toward cervix carcinoma HeLa cell lines; three were cytotoxic against breast carcinoma MCF-7 cells, while one inhibited proliferation of colon carcinoma HT 29 cell lines. Only one compound was cytotoxic toward normal cell lines, while other compounds were proven as safe. Antiproliferative potential against HeLa cells was described as exponential function of lipophilicity. Based on obtained results, lead compounds were selected.

In this paper, spectroscopic and quantum mechanical investigation of nine 4-aryl-5-arylazo-3-cyano-6-hydroxy-2-pyridone dyes was performed, and obtained density functional theory (DFT) results were compared with experimental data. The structural and spectroscopic properties of azo-2-pyridone dyes were studied by DFT using B3LYP, CAM-B3LYP, and M06-2X methods with a 6-311++G(d,p) basis set. Comparison of results reveals that the scaled theoretical vibrational frequencies of azo dyes are in good agreement with experimental data. The time-dependent DFT calculated and experimental ultraviolet-visible (UV-vis) absorption spectra are also in good agreement. The effect of electron-donating -OCH3 and electron-withdrawing -NO2 groups on the structural parameters, vibrational frequencies, UV-vis absorption, and natural bond orbital (NBO) atomic charges were thoroughly analysed. Vibrational, UV-vis, and NBO analyses confirm that investigated dyes exist in the hydrazo tautomeric form in the solid state and ethanol solution. These analyses signify the occurrence of intramolecular charge transfer in these azo-pyridone dyes.

The present study is focused on a series of newly synthesized 1-aryl-3-ethyl-3-methylsuccinimide derivatives, as potential anticonvulsants. The retention behavior of eleven succinimide derivatives was determined by using reversed phase high performance liquid chromatography (RP-HPLC) and reversed phase high performance thin layer chromatography (RP-HPTLC). The estimated retention behavior was correlated with partition (logP) and distribution coefficients (logD). These high correlations pointed out that the determined retention parameters (logK(0) and R-M(0)) can be considered chromatographic (anisotropic) lipophilicity of the studied succinimide derivatives. The structural properties, which dominantly affect the chromatographic lipophilicity, were determined as well. The significant correlations between the chromatographic lipophilicity and plasma protein binding (PPB), Madin-Darby Canine Kidney (MDCK) cells permeability, volume of distribution (Vd) and absorption constant (Ka) indicate the strong influence of lipophilicity on pharmacokinetics of 1-aryl-3-ethyl-3-methylsuccinimide derivatives. These derivatives have also been tested applying Comprehensive Medicinal Chemistry (CMC) drug-like rules which confirmed their drug-like properties. Besides, their blood-brain penetration (BBB) ability has been estimated applying the set of Clark's rules and by using Pre-ADMET software. Regarding toxicity, it was predicted that only one compound from the set might have toxic effects by blocking the hERG potassium channel. The present study reveals which molecular features in the structure of novel succinimide derivatives could be crucial for their lipophilicity, and consequently for their pharmacokinetic properties. The results indicate that the newly synthesized series of succinimide derivatives should be further considered in design of novel anticonvulsants.

New synthesized compounds, particularly those with biological activity, are potential drug candidates. This article describes experimental studies performed to estimate lipophilicity parameters of new 3-(4-substituted benzyl)-5-phenylhydantoins. Lipophilicity, as one of the most important molecular characteristics for the activity, was determined using the reversed-phase liquid chromatography (RP-18 stationary phase and methanol-water mobile phase). Molecular structures were used to generate in silico data which were used to estimate pharmacokinetic properties of the investigated compounds. The results show that generally, the investigated compounds attain good bioavailability properties. A more detailed analysis shows that the presence of a nitro, methoxy and tert-butyl group in the molecule is indicated as unfavorable for the oral bioavailability of hydantoins. Multivariate exploratory analysis was used in order to visualize grouping patterns among molecular descriptors as well as among the investigated compounds. Molecular docking study performed for two hydantoins with the highest bioavailability scores shows high binding affinity to tyrosine kinase receptor IGF-1R. The results achieved can be useful as a template for future development and further derivation or modification to obtain more potent and selective antitumor agents.

Numerous structurally different amides and imides including succinimide derivatives exhibit diverse bioactive potential. The development of new compounds requires rationalization in the design in or- der to provide structural changes that guarantee favorable physico-chemical properties, pharmacological activity and safety. In the present research, a comprehensive study with comparison of the chromato- graphic lipophilicity and other physico-chemical properties of five groups of 1-arylsuccinimide derivatives was conducted. The chemometric analysis of their physico-chemical properties was carried out by us- ing unsupervised (hierarchical cluster analysis and principal component analysis) and supervised pattern recognition methods (linear discriminant analysis), while the correlations between the in silico molecular features and chromatographic lipophilicity were examined applying linear and non-linear Quantitative Structure–Retention Relationship (QSRR) approaches. The main aim of the conducted research was to determine similarities and dissimilarities among the studied 1-arylsuccinimides, to point out the molec- ular features which have significant influence on their lipophilicity, as well as to establish high-quality QSRR models which can be used in prediction of chromatographic lipophilicity of structurally similar 1-arylsuccinimides. This study is a continuation of analysis and determination of the physico-chemical properties of 1-arylsuccinimides which could be important guidelines in further in vitro and eventually in vivo studies of their biological potential.

To create new anticonvulsant drugs, two series of spirohydantoins derived from β-tetralone bearing a 4-substituted benzyl group (1a−1g) or a 2-(4-substituted phenyl)-2-oxoethyl group (2a−2f) in position 3 of the hydantoin ring were synthesized. The chemical structure of these compounds was confirmed by determination of the melting point, elemental analysis and FT-IR, 1H NMR, 13C NMR and UV-Vis spectroscopic methods. Effects of the substituents in the benzyl moiety on the shift of the absorption maxima of compounds 1a−1g and 2a−2f were analyzed using the Hammett's equation. Namely, a split in the Hammett plot at the parent compounds 1a and 2a revealed different electronic transitions within the molecules with the electron-donating substituents from those bearing the electron-accepting substituents, thus the electron-accepting effect on the shift of the absorption maxima being considerably stronger. The influence of the chemical structure on the pharmacokinetically relevant properties of the investigated hydantoin derivatives was evaluated using the Lipinski’s rule of five, Veber, Egan and Ghose's empirical criteria, as well as different in silico methods. When compared to phenytoin (5,5-diphenylhydantoin) as the referent drug, compounds with a halogen or electron-donating substituent are expected to possess better intestinal absorption and passage through the blood-brain barrier. Depending on the nature of the substituent present in the benzyl moiety, compounds 1a−1g and 2a−2f can be potent activators/inhibitors of some cytochrome P450 izoenzymes including CYP1A2, CYP2C19 and CYP2C9. Regarding biological activity profile, compounds with the electron-accepting substituents are likely to reveal the pharmacological potential similar to that of phenytoin, while those bearing electron-donating substituents are predicted to have the antimigrenic activity. All compounds were found to bear a low risk of being mutagenic or tumorigenic. The calculated molecular descriptors indicate that the investigated compounds fulfill necessary empirical criteria which qualify them as interesting drug candidates. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172013]

Two series of cycloalkanespiro-5-hydantoins, namely cyclohexanespiro-5-hydantoins and cycloheptanespiro-5-hydantoins with a 4-substituted benzyl or a 2-(4-substituted phenyl)-2-oxoethyl group at N3 position, were synthesized and their effects on proliferation of human colon (HCT-116), leukemia (K562) and breast (MDA-MB-231) cancer cell lines were tested. For comparison, we also described the 5,5-diphenylhydantoin analogues. The structural features of the investigated compounds were characterized by elemental analysis, FT-IR, UV–Vis, 1 H and 13 C NMR spectroscopy and X-ray crystallography. Regarding their structure–activity relationships, it was shown that the substitution on the benzyl moiety with the methoxy, chloro or bromo group potentiated the antiproliferative activity relative to the parent compounds, while an increase in the size of the cycloalkyl group resulted mostly in a decrease of the antiproliferative activity. The single crystal X-ray analysis revealed the existence of dimers and chains formed by the N–H⋯O hydrogen bonds. The analysis of the molecular descriptors of Lipinski demonstrated that all investigated compounds obeyed the rule of five. To further understand their geometry and electronic structure, DFT calculations with B3LYP method using 6-311++G(d,p) basic set were performed. In this context, the UV–Vis spectra of the investigated compounds were analyzed in detail, whereby the predicted absorption spectra from DFT calculation matched the experimentally obtained ones, with a good correlation. The interesting physico-chemical and pharmacologically relevant properties of the investigated compounds warrant their further investigation. Published version: [http://technorep.tmf.bg.ac.rs/handle/123456789/4324] This is the peer-reviewed version of the following article: Lazić A, Radovanović L, Božić B, Božić-Nedeljković B, Vitnik V, Vitnik Ž, Rogan J, Valentić N, Ušćumlić G, Trišović N. Synthesis, structural characterization, DFT calculations and antiproliferative evaluation of novel spirohydantoin derivatives containing a substituted benzyl moiety. in Journal of Molecular Structure. 2019;1180:48-62. [https://doi.org/10.1016/j.molstruc.2018.11.071]

Novel succinimide derivatives were synthesized from 3-methyl-3-phenylsuccinic acid and substituted anilines under solvent-free conditions by using microwave irradiation. All obtained compounds were characterized by ultraviolet (UV), Fourier-transform infrared (FT-IR), 1H and 13С nuclear magnetic resonance (NMR) spectroscopy as well as by elemental analysis. The influence of the substituent electronic effects on spectroscopic data was analyzed by applying the Hammett equation. Moreover, a detailed interpretation and comparison of experimentally obtained and theoretically calculated FT-IR, UV and NMR spectra was performed. Density functional theory (DFT) calculated data of the investigated succinimides were obtained and analyzed in order to determine their structural, spectroscopic and electronic properties. Furthermore, ADMET factor profiling and in-silico prediction of potential biological activities of novel succinimide derivatives have been performed. Novi derivati sukcinimida sintetisani su polazeći od 3-metil-3-fenilćilibarne kiseline i supstituisanih analina u mikrotalasnom reaktoru u odsustvu rastvarača. Sva jedinjenja su okarakterisana primenom UV-vidljive spektroskopije, infracrvene spektroskopije sa Furijeovom transformacijom (FT-IR), protonske nuklearne magnetne rezonancije (1H NMR), nuklearne magnetne rezonancije ugljenika-13, (13С NMR), kao i elementalnom analizom. Uticaj elektronskih efekata supstituenata na spektroskopske podatke analiziran je upotrebom Hametove jednačine. Takođe, izvršena je detaljna interpretacija, kao i poređenje eksperimentalno dobijenih i teorijski izračunatih FT-IR, UV i NMR spektara. Pored toga, urađeno je ADMET (engl. absorption, distribution, metabolism, excretion and toxicity) profilisanje i in-silico predviđanje potencijalne biološke aktivnosti novosintetisanih derivata sukcinimida.

The macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine involved in inflammation, regulation of energy metabolism and glucocorticoid action. Chronic low-grade inflammation may be caused by fructose intake, contributing to visceral adipose tissue (VAT) dysfunction. Since MIF is a known antagonist of glucocorticoid signaling, and deregulated glucocorticoid signaling can contribute to lipid metabolism disturbances, we hypothesized that altered MIF signaling might underlie fructose-induced adiposity through glucocorticoid action. We analyzed physiological and biochemical parameters, adipose tissue histology, insulin sensitivity and lipid metabolism in wild type and MIF-/- C57Bl/6J mice consuming 20% fructose solution for 9 weeks. Glucocorticoid prereceptor metabolism and glucocorticoid receptor (GR) protein level were examined in VAT, together with the expression of glucocorticoid-target genes involved in lipid metabolism. The expression of adipogenic and lipogenic transcriptional regulators peroxisome proliferator activated receptor gamma (PPARG) and sterol regulatory element-binding protein 1c (SREBP1c) was also assessed. Results showed disturbed insulin sensitivity in all MIF-/- mice, regardless of the diet. Mice on fructose diet had increased energy intake, but increased visceral adiposity and enlarged adipocytes were observed only in fructose-fed MIF-/- mice. Increased VAT corticosterone level and 11 beta-hydroxysteroid dehydrogenase type 1, hexose-6-phosphate dehydrogenase and GR protein levels were observed in the same animals, together with induced expression of examined lipogenic genes and accumulation of PPARG and SREBP1c. In conclusion, the results showed that dietary fructose was associated with increased visceral adiposity through activation of GR-regulated lipogenic genes, but only in the absence of MIF, which set the state of hyperinsulinemia and insulin resistance.

Background: Hydantoin and its newly synthesized derivatives have recently become a focus of interest due to their numerous biological activities and newly emerging beneficial effects in different pathological conditions, including cancer. Objective: The aim of this study was to evaluate the possible anti-tumor mechanisms of a series of newly synthesized 3-(4-substituted benzyl)-5-isopropyl-5-phenylhydantoin derivatives in different aspects of cell physiology of human colon cancer cell line, HCT-116. Methods: The increasing concentrations of derivatives (0.01µM up to 100µM) were applied to cells during 24h, 48h, and 72h after which the evaluation of proliferation, apoptosis, oxidative/anti-oxidative status, nitrite production, and migration/invasion potential of treated cells was performed. Results: All tested compounds expressed the dose- and time-dependent anti-proliferative and pro-apoptotic activities against HCT-116 cells. The investigated derivatives induced a decrease in levels of oxidative stress parameters and an increase in levels of nitrite production by treated cells suggesting their significant antioxidative effects. The cell migration index and expression level of tumor invasion-promoting metalloproteinase- 9 (MMP-9) gene were significantly decreased after treatment with the tested hydantoin derivatives implicating their inhibitory role in colon cancer cell motility and invasion processes. The mRNA level of cyclooxygenase-2 (COX-2) gene as a pro-inflammatory gene related to colorectal carcinogenesis was reduced compared to values in the non-treated control cells indicating the significant anti-inflammatory/anti-tumor effects of these compounds. Conclusion: The obtained results show the significant anti-tumor potential of tested derivatives, especially 3- benzyl-5-isopropyl-5-phenylhydantoin and 3-(4-chlorobenzyl)-5-isopropyl-5-phenylhydantoin, suggesting their potential usage in the development of more effective chemotherapies.

Spirohidantoins represent an pharmacologically important class of heterocycles since many derivatives have been recognized that display interesting activities against a wide range of biological targets. First synthesis of cycloalkanespiro-5-hydantoins was performed by Bucherer and Lieb 1934 by the reaction of cycloalkanone, potassium cyanide and ammonium-carbonate at reflux in a mixture of ethanol and water. QSAR (Quantitative Structure-Activity Relationship) studies showed that a wide range of biological activities of spirohydantoin derivatives strongly depend upon their structure. This paper describes different methods of synthesis of spirohydantoin derivatives, their physico-chemical properties and biological activity. It emphasizes the importance of cycloalkanespiro-5-hydantoins with anticonvulsant, antiproliferative, antipsychotic, antimicrobial and antiinflammatory properties as well as their importance in the treatment of diabetes. Numerous spirohydantoin compounds exhibit physiological activity such as serotonin and fibrinogen antagonist, inhibitors of the glycine binding site of the NMDA receptor also, antagonist of leukocyte cell adhesion, acting as allosteric inhibitors of the protein-protein interactions. Some spirohydantoin derivatives have been identified as antitumor agents. Their activity depends on the substituent presented at position N-3 of the hydantoin ring and increases in order alkene > ester > ether. Besides that, compounds that contain two electron withdrawing groups (e.g. fluorine or chlorine) on the third and fourth position of the phenyl ring are better antitumor agents than compounds with a single electron withdrawing group. [Projekat Ministarstva nauke Republike Srbije, br. 172013]

A series of dual-sensitive poly(2-hydroxyethyl acrylate/itaconic acid) (P(HEA/IA)) hydrogels were synthesized and evaluated as drug delivery systems for potential antiproliferative agents. Investigated hydrophobic compounds, Mn(II) and Zn(II) complexes with Oxaprozin, were efficiently loaded into the P(HEA/IA) hydrogels, which was confirmed by FTIR and UV-Vis spectroscopy. Swelling studies, conducted in the physiological pH range of 2.20-8.00 and in temperature range of 30-50 A degrees C, demonstrated that loaded transition metal complexes in P(HEA/IA) hydrogels did not annul pH and temperature sensitivity of the hydrogels. In vitro antiproliferative activity of Mn(II) and Zn(II) complexes with Oxaprozin against human cervical (HeLa) and melanoma cancer (Fem X) cell lines was tested. Results of in vitro release study investigated at different pH conditions confirmed P(HEA/IA) hydrogels as a highly effective pH-triggered drug delivery system for hydrophobic antiproliferative agents. These performances indicate that P(HEA/IA) hydrogels loaded with transition metal complexes can be further studied as a promising candidate for anticancer therapy, as well as for targeted treatment of intestine/colon cancers.

Eight 5-(4-substituted arylazo)-4-phenyl-6-methyl-3-cyano-2-pyridones were synthesized by reaction of benzoylacetone and arendiazonium salt, followed by condensation with cyanoacetamide. Absorption spectra of all azo pyridone dyes were recorded in twelve protic and aprotic solvents in the range of 200-600 nm. A simple Hammett equation was used to study the effect of the substituents on the absorption spectra of these azo dyes. The solute-solvent interactions were clarified on the basis of linear solvation energy relationships concept proposed by Kamlet and Taft. The results showed that the solvent effects on the absorption spectra of the investigated azo dyes were very complex and strongly dependent on the nature of the substituents on the phenylazo group. Osam 5-(4-supstituisanih arilazo)-4-fenil-6-metil-3-cijano-2-piridona je sintetizovano reakcijom benzoilacetona i arendiazonijumove soli, i kondenzacijom nastalog proizvoda sa cijano-acetamidom. Apsorpcioni spektri dobijenih arilazo piridonskih boja su snimljeni u dvanaest protičnih i aprotičnih rastvarača u opsegu od 200-600 nm. Za proučavanje uticaja supstituenata na apsorpcione spektre ispitivanih azo boja korišćena je prosta ametova jednačina. Interakcije rastvorak-rastvarač su razjašnjene na osnovu koncepta linearne korelacije energije solvatacije, koji su predložili Kamlet i Taft. Rezultati pokazuju da su efekti rastvarača na apsorpcione spektre istraženih azo boja veoma kompleksni i jako zavise od prirode supstituenata na fenilazo grupi.

Disazo pyridone dye, 4-methyl-2,6-dioxo-5-(2-(4-(phenyldiazenyl)phenyl)hydrazono)-1,2,5,6-tetrahydropyridine-3-carbonitrile, is synthesised and thoroughly characterised by a combination of experimental and computational approaches. Fourier Transform-infrared and nuclear magnetic resonance (NMR) spectra prove the existence of the hydrazone form in the solid state and in dimethyl sulphoxide, which is also supported by vibrational and NMR theoretical studies. Ultraviolet (UV) spectral properties, as well as solvatochromism in 19 solvents of different polarity, are investigated. In most of the solvents, the dye is solely present in the hydrazone form, whereas in certain solvents, an acid-base equilibrium exists. Excellent agreement between computational and experimental UV-visible data was established. Frontier Molecular Orbital analysis was performed and proved the existence of intramolecular charge transfer through the dye molecule. A molecular electrostatic potential surface was plotted over the optimised geometry to lighten the reactivity of the investigated molecule.

Ten 5-(substituted phenylazo)-3-cyano-1-ethyl-6-hydroxy-4-methyl-2-pyridones were studied (five new compounds) to provide insight into the electronic effects of diverse substituents located at different positions in their phenyl moieties. The structural features of these dyes were examined by combining experimental and theoretical approaches. The crystal structures of two derivatives were revealed by X-ray crystallography and diverse packing modes owing to different intermolecular interactions (- stacking and lone pair- interactions, as well as hydrogen bonds) were found. A study on lattice energy and energy related to the molecular pairs obtained from their crystal packing was performed. The tautomerism and ionisation of the dyes in ethanol or N,N -dimethylformamide solution were rationalised in terms of diazo component substitution pattern.

Spectral properties, solvatochromism and azo-hydrazone tautomerism of ten 5-(substituted phenylazo)-3-cyano-6-hydroxy-1-(2-hydroxyethyl)-4-methyl-2-pyridones in twenty-two solvents are investigated. For quantitative evaluation of the solvent effects on the UV–vis absorption maxima, the principles of the linear solvation energy relationships are used, i.e. models proposed by Kamlet–Taft and Catalan. Linear free energy relationships are applied to the UV–vis absorption spectra and correlation of absorption frequencies with Hammett substituent constants are performed. Furthermore, the influence of the electronic nature of the substituents on 1H and 13C NMR shifts is investigated by simple and extended Hammett equations, as well as by Swain–Lupton equation.

Quantitative structure-retention relationship (QSRR) study of retention data of thirteen 5-arylidene-2,4-thiazolidinediones obtained by reversed phase HPTLC. The effect of substituents attached to aryliden ring on the properties of TZD molecule, whose retention is closely correlated to the inhibitory activity, was investigated. PCA was used to show similarities/dissimilarities among the compounds. Stepwise regression models were calculated for each mobile phase modifier used. The obtained models were characterized by good fit and predictive abilities. The descriptors included in the models are connected with both lipophilic and donor/acceptor interactions.

Two series of 1-aryl-3-phenyl- and 1-aryl-3,3-diphenylpyrrolidine-2,5-diones were synthesized and their solvatochromic properties were studied in a set of 15 solvents of different polarity. The effect of specific and non-specific solvent-solute interactions on the position of their absorption bands was evaluated by using the solvent parameter sets of Kamlet and Taft. The interpretation of the effect of different substituent patterns on the solvatochromic properties of the investigated compounds was based on quantum chemical calculations performed by the density functional theory (DFT)/CAM-B3LYP method using the 6-311G(d,p) basis set. The theoretical absorption frequencies show very good agreement with the experimental values. The energy gaps between the HOMO and LUMO orbitals were also analyzed. It is demonstrated that different substituents change the conjugation effect and further determine the pathways of intramolecular charge transfer.

The kinetics of the reaction of benzoic, 2-methylbenzoic, phenylacetic, cyclohex-1-enecarboxylic, 2-methylcyclohex-1-enecarboxylic, and cyclohex-1-eneacetic acids with diazodiphenylmethane was studied at 30, 33, 37, 40, and 45°C in a set of 12 protic and aprotic solvents. The reactions were found to follow the second-order kinetics. The activation energy as well as the activation parameters, such as the standard entropy, the standard enthalpy, and the standard Gibbs energy of the activation, was calculated from the second-order rate constants. The solvent and structural effects on the activation energy and the standard Gibbs energy of activation, for each examined compound, were analyzed. The results of Kamlet–Taft multiple correlation analysis show that the specific solvent–solute interactions play a dominant role in the governing of the reaction. The signs of the equation coefficients support the proposed reaction mechanism.

The structure-property relationship of newly synthesized 3-(4-substituted benzyl)-1,3-diazaspiro [4.4] nonane-2,4-diones was studied by experimental and calculated methods. The prepared compounds were characterized by UV-Vis, FT-IR, H-1 NMR and C-13 NMR spectroscopy and elemental analysis. The crystal structure was elucidated by single-crystal X-ray diffraction. The 3-benzy1-1,3-diazaspiro[4.41nonane-2,4-dione crystallizes in triclinic P-1 space group, with two crystallographically independent molecules in the asymmetric unit. Cyclopentane ring adopts an envelope conformation. A three-dimensional crystal packing is governed by hydrogen N-H center dot center dot center dot O bonds, numerous C-H center dot center dot center dot O/N and C-H center dot center dot center dot pi interactions between neighboring molecules. Density functional theory (DFT) calculations with B3LYP and M06-2X methods using 6-311++G(d,p) basis set were performed to provide structural and spectroscopic information. Comparisons between experimental and calculated UV-Vis spectral properties suggest that the monomeric form of the investigated spirohydantoins is dominant in all used solvents. The effects of substituents on the absorption spectra of spirohydantoins are interpreted by correlation of absorption frequencies with Hammett equation. The lipophilicities of the investigated molecules were estimated by calculation of their log P values. Some of the spirohydantoins synthesized in this work, exhibit the lipophilicities comparable to the standard medicine anticonvulsant drug Phenytoin. The results obtained in this investigation afford guidelines for the preparation of new derivatives of spirohydantoin as potential anticonvulsant agents and for better understanding the structure-activity relationship.

A series of ten 1-aryl-3-methylsuccinimides was synthesized and their solvatochromic properties were studied in a set of fifteen binary solvent mixtures. The solute-solvent interactions were analyzed on the basis of the linear solvation energy relationship (LSER) concept proposed by Kamlet and Taft. The electronic effect of the substituents on the UV-Vis absorption and NMR spectra was analyzed using the simple Hammett equation. Moreover, the B3LYP, CAM-B3LYP, and M06-2X functionals using the 6-311G(d,p) basic set have been assessed in light of the position of experimental absorption maxima obtained for these compounds. The integration grid effects have also been evaluated. An interpretation of the substituent-effect transmission through the molecular skeleton and the nature of the HOMO and LUMO orbitals based on quantum-chemical calculations is given. The values of partial atomic charges from the atomic polar tenzors (APT), natural population analysis (NBO), and charges fit to the electrostatic potential using the B3LYP, CAM-B3LYP, and M06-2X methods are produced and correlated with different experimental properties. In order to estimate the chemical activity of the molecule, the molecular electrostatic potential (MEP) surface map is calculated for the optimized geometry of 1-phenyl-3-methylsuccinimide. This is peer-reviewed version of the article: N.R. Banjac, B.E. Božić, J.M. Mirković, V.D. Vitnik, E.J. Vitnik, N.V. Valentić, G.S. Ušćumlić, Experimental and theoretical study on the structure-property relationship of novel 1- aryl-3-methylsuccinimides, Journal of Molecular Structure, 2017, 1129, 271-282 [https://dx.doi.org/10.1016/j.molstruc.2016.09.086] [http://cer.ihtm.bg.ac.rs/handle/123456789/2054]

A series of six novel 2-(5-arylidene-2,4-dioxotetrahydrothiazole-3-yl)propanoic acids and six corresponding methyl esters were synthesized. All compounds were characterized by melting points, elemental analysis, FT-IR, 1H and 13C NMR spectroscopy. Crystal structure of methyl-2-(5-(4-methoxybenzylidene)-2,4--dioxotetrahydrothiazole-3-yl)propionate was confirmed by X-ray analysis. The antiproliferative activity of all synthesized compounds against human colon cancer, breast cancer and myelogenous leukemia cell lines, i.e. HCT-116, MDA-231 and K562, respectively, was evaluated. The results indicate that antiproliferative activity of the synthesized esters is better than the activity of the corresponding acids. All synthesized compounds showed significant antiproliferative effects against HCT116 cells in all tested concentrations (0.01–100 μM). Moreover, in vitro antimicrobial activity against a wide range of tested microorganisms was examined.

A series of cycloalkane-5-spirohydantoins bearing a halogeno substituted benzyl group (X = Cl and Br) in position 3 has been synthesized and their structures (1-6) have been determined by a single crystal X-ray diffraction method. These compounds have multiple functional groups, which allow greater competition and/ or cooperation among the different intermolecular interactions in the formation of their crystal structures. The molecules are linked together by paired N-H... O hydrogen bonds in R22(8) rings, while the CH. O interactions lead to their further association into double chains. The contribution of the cycloalkyl ring depends on its conformational flexibility and the multiple C-H donor implications. In the case of compounds 1-4 bearing the cyclopentyl or the cyclohexyl ring, halogen bonding (X...O) interactions give rise to a supramolecular pseudo-hexagonal network. In addition, the C-H... X interactions with a higher degree of multifurcation at the halogen acceptor have an important role in the formation of the crystal structure. Regarding compounds 5 and 6 with the cycloheptane ring, the X. O interaction is absent, and along with the C-H. X interactions, these compounds realize an alternative crystal structure with an emphasis on the X. p interactions. The lattice energies of all these crystal structures, as well as the intermolecular pair energies, have been calculated using PIXEL and further partitioned into coulombic, dispersive, polarization and repulsive factors. The crystal structures have also been subjected to Hirshfeld surface analysis which reveals that approximately 75% of the close contacts correspond to relatively weak interactions. The application of both concepts has provided a new insight into the relationship between the molecular interactions and crystal structures of the hydantoin derivatives. This is the peer-reviewed version of the following article: Crystengcomm, 2017, 19, 3, 469-483 [https://dx.doi.org/10.1039/C6CE02210C] [http://cer.ihtm.bg.ac.rs/handle/123456789/2204]

In the last three or four decades disperse dyes derived from pyridones (in particular azo pyridone dyes) have gained in importance, and are widely used in various fields. These compounds have excellent coloration properties, and are suitable for the dyeing of polyester fabrics. Basic features of these dyes are simplicity of their synthesis by diazotation and azo coupling. They generally have high molar extinction coefficient with medium to high light and wet fastness. The absorption maxima of these dyes show their visible absorption wavelength ranging from yellow to orange, which can be attributed to poorly delocalized electrons in the pyridone ring. However, there are several dyes with deep colors such as red or violet. Pyridone dyes with alkyl and aryl groups in ortho position to azo group show 2-pyridone/2-hydroxypyridine tautomerism, while those containing OH and NHR groups conjugated with the azo group show azo-hydrazone tautomerism. Determining azo-hydrazone tautomerism could be therefore interesting, since the tautomers have different physico-chemical properties and most importantly different coloration. The literature on azo-hydrazone tautomerism, determination of equilibrium position, and investigation of substituent and solvent influence on tautomerism has been summarized in the presented review. The general conclusion is that the equilibrium between two tautomers is influenced by the structure of the compounds and by the solvents used. The tautomeric behavior patterns of the arylazo pyridone dyes in the reviewed literature has been studied using various instrumental techniques, including FT-IR, UV-vis, and NMR spectroscopy. The quantum chemical calculations related to the azo-hydrazon tautomerism have also been included. A large number of pyridone dyes exist in hydrazone form in solid state, while in solvents there is a mixture of tautomers. In addition, the X-ray single-crystal diffraction data analysis of some commercial pyridone dyes has been discussed concluding that they all crystallize in the hydrazone form. Arilazo piridonske boje su obojene supstance koje zbog svojih specifičnih svojstava kao i primene u različitim industrijskim oblastima predstavljaju značajan predmet istraživanja u poslednjih nekoliko decenija. Osnovna svojstva ovih boja su visoki ekstinkcioni koeficijenti kao i dobra postojanost na mokre obrade. Arilazo piridonske boje su pogodne za bojenje sintetskih vlakana i daju nijanse izmeću žute i narandžaste. Zbog uticaja strukture na obojenost, azo-hidrazon tautomerija je tema velikog broja radova. U ovom radu sumirana su dosadašnja istraživanja koja se odnose na azo-hidrazon tautomeriju arilazo pridonskih boja, kao i na mogućnost odrećivanja odnosa tautomera korišćenjem različitih spektroskopskih metoda. Osim toga, razmatrana su i istraživanja koja se bave ispitivanjem kristalne strukture tautomera koji se koriste kao komercijalne boje.

In the study, 18 antiepileptic hydantoin analogues were investigated by means of reversed-phase HPLC on C-18 stationary phase and eluent acetonitrile-water. Quantitative structure-retention relationship (QSRR) study has been applied in order to understand factors that affect the retention which is closely correlated to the activity (ED50 values). To overview the compounds for similarities and dissimilarities principal component analysis (PCA) has been applied. Six multiple linear regression models based on the most relevant descriptors were developed. Descriptors for MLR were selected according to variable importance calculated by partial least squares (PLS) analysis. Besides ALOGP the most important is aromatic ratio for mobile phases with more than 45% of acetonitrile, as well as electrotopological states when the % of acetonitrile is less than 40%. High agreement between experimental and predicted retention, obtained in the validation procedure, indicated the good quality of the derived QSRR models. For individual linear models, cross-validation squared correlation coefficients (Q(2)) ranging from 0.697 to 0.837 were obtained. The residual values (difference between observed and calculated) agreed well within experimental error. Additionally, models were compared in terms of the smallest residual value by recently developed method of ranking based on the sum of ranking differences (SRD).

Molecular properties relevant to pharmacokinetics of two sets of newly synthesized hydantoin derivatives based on two well-known drugs (Nirvanol and Phenytoin) were studied. Properties under consideration were either determined empirically by reversed-phase high-performance thin-layer chromatography or calculated by the use of established theoretical medicinal chemistry/drug design software. These properties represent selected structural features of analytes, which affect their processes of absorption, distribution, metabolism, excretion, and toxicity. Principal component analysis was used to visualize the differences between six mobile phase modifiers used as well as similarities between 24 analyzed compounds. To find appropriate quantitative relationships between RM, W for the tested compounds and molecular descriptors, stepwise regression, partial least squares (PLS), and robust PLS were used. The best results were obtained with robust PLS. Copyright © 2012 John Wiley & Sons, Ltd.

The absorption spectra of twelve 5-arylidene-2,4-thiazolidinediones were recorded in twenty one solvents in the range from 300 to 600 nm. The effect of specific and non-specific solvent-solute interactions on the absorption maxima shifts were evaluated by using the Catalan solvent parameter set. Furthermore, the experimental findings were interpreted with the aid of ab initio MP2 and time-dependent density functional (TD-DFT) methods. It was found that different substituents significantly change the extent of conjugation in the molecules and further affect their intramolecular charge transfer character. (C) 2011 Elsevier B.V. All rights reserved.

The properties relevant to pharmacokinetics of two series of newly synthesized succinimide derivatives have been studied. The properties under consideration have been either determined empirically, by reversed-phase liquid chromatography (TLC and HPLC technique), or calculated with the use of established theoretical medicinal chemistry/drug design software. Chromatographic techniques allowed determination of the retention constants R(M)⁰ and log k(w), which characterize lipophilicity of compounds. Considering potential pharmaceutical importance of succinimide derivatives, we (i) examined the retention behavior in the reversed-phase liquid chromatographic (RP LC) systems, in both planar and column LC, and (ii) determined the relationships between chromatographic data and selected structural features of analytes that are believed to markedly affect their processes of absorption, distribution, metabolism, excretion and toxicity (ADMETox). Significant relationships were found between the retention constants, R(M)⁰ and log k(w), and the in silico calculated bioactivity descriptors, in particular HIA (human intestinal absorption) and PPB (plasma protein binding) parameters. The R(M)⁰ and log k(w) values of the investigated compounds have been recommended for description of their lipophilicity and evaluating pharmacokinetic properties. In view of results of this study the newly synthesized succinimide agents meet pharmacokinetic criteria of preselection of drug candidates and hence qualify for pharmacodynamic phase of antiepileptic drug development. Best compromising human intestinal absorption and plasma protein binding features appear to be compounds A4, A5, A10 and A11.

In this study 18 hydantoin derivatives were investigated by means of reversed-phase LC on C-18 stationary phase and methanol–water eluent. Quantitative structure–retention relationship study has been applied in order to understand factors that affect the chromatographic behavior which is closely correlated to the activity (ED50 values). A multiple linear regression procedure was used to model the relationships between molecular descriptors and retention of the hydantoin derivatives. The best quantitative structure–activity relationship (QSAR) models were further validated by a leave-one-out technique as well as by the calculation of statistical parameters for the established theoretical models. High agreement between experimental and predicted data obtained in the validation procedure indicated good quality of the derived QSAR models.

A new procedure for the synthesis of known azo pyridone dyes is presented. A series of 5-(substituted arylazo)-6-hydroxy-4-methyl-3- cyano-2-pyridones were prepared from ethyl 3-oxo-2-(substituted phenyldiazenyl)butanoates and cyanoacetamide in acetone using potassium hydroxide as a catalyst by simple refluxing the reaction mixture. The structure of these dyes was confirmed by FT-IR, NMR and UV-Vis spectroscopy.

Over 50% of all colorants which are used nowdays are azo dyes and pigments, and among them arylazo pyridone dyes (and pigments) have became of interest in last several decades due to the high molar extinction coefficient, and the medium to high light and wet fastness properties. They find application generally as disperse dyes. The importance of disperse dyes increased in the 1970s and 1980s due to the use of polyester and nylon as the main synthetic fibers. Also, disperse dyes were used rapidly since 1970 in inks for the heat-transfer printing of polyester. The main synthetic route for the preparation of azo dyes is coupling reaction between an aromatic diazo compound and a coupling component. Of all dyes manufactured, about 60% are produced by this reaction. Arylazo pyridone dyes can be prepared from pyridone moiety as a coupling component, where substituent can be on nitrogen, and diazonim salts which can be derived from different substituted anilines or other heterocyclic derivatives. In addition, arylazo dyes containing pyridone ring can be prepared from arylazo diketones or arylazo ketoesters (obtained by coupling 2-diketones or 2-ketoesters with diazonim salts) by condensation with cyanoacetamide. Disazo dyes can be prepared by tetrazotizing a dianiline and coupling it with a pyridone or by diazotizing aniline and coupling it with a dipyridone. Trisazo dyes can be also prepared by diazotizing of aniline and coupling it with a tripyridone or by hexazotizing a trianiline and coupling it with a pyridone. the main goal of this paper is to give a brief review on the synthesis of arylazo pyridone dyes due to the lack of such reviews. In addition, some properties of arylazo pyridone dyes as light fastness and azo-hydrazon tautomerism are disccused. Preko 50% svih obojenih supstanci koje se danas koriste su azo boje i pigmenti. U ova jedinjenja spadaju i arilazo piridonske boje (i pigmenti), koje se koriste kao disperzne boje, a takođe nalaze primenu i kao komponente u inkdžet grafičkim bojama i LCD ekranima. Kada se koriste kao disperzne boje uglavnom daju žute nijanse i poseduju dobru do odličnu postojanost na mokre obrade i svetlost. U ovom radu je dat kratak prikaz sinteze arilazo piridonskih boja pri čemu je na izabranim primerima ilustrovana sinteza monoazo, disazo i trisazo boja na bazi piridona. Osnovni način dobijanja azo boja pa i arilazo piridonskih boja je reakcija diazokuplovanja, koja se kombinuje sa drugim reakcijama da bi se dobile boje željene strukture. U rada su takođe razmatrana svojstva arilazo pirodonskih boja, kao što su postojanost na svetlost i azo-hidrazon tautomerija.

Oxaprozin (3-(4,5-diphenyloxazol-2-yl)propanoic acid) is a nonsteroidal anti-inflammatory drug (NSAID) used in the treatment of numerous inflammatory musculoskeletal diseases, including rheumatoid arthritis, osteoarthritis, tendonitis, ankylosing spondylitis and bursitis. It is the first representative member of the diaryl- substituted heterocyclic compounds, which have found clinical use as selective cyclooxygenase-2 (COX-2) inhibitors. The U.S. Food and Drug Administration (FDA) approved its official use in 1992. Both the anti-inflammatory and analgesic properties of oxaprozin are mainly due to the potent inhibition of COX. However, oxaprozin-induced benefits might be also regulated by other COX-independent pathways. It has been shown that oxaprozin induced direct proapoptotic effects in CD40L-treated human monocytes independently of COX inhibition. It also has several advantages in the treatment of inflammatory diseases in comparison to other NSAIDs such as aspirin, naproxen, indomethacin and phenylbutazone, which enabled oxaprozin to become one of the most used NSAIDs in America. Oxaprozin, as other members of the group of NSAIDs, can cause gastrointestinal complications, but significantly lower due to relatively high pKa value. In this paper, the importance of oxaprozin in the treatment of arthritis and its pharmacokinetic properties were described, therewith its activity and side effects were compared with other commercially available anti-inflammatory drugs. Oksaprozin (3-(4,5-difeniloksazol-2-il)propanska kiselina) jeste nesteroidni anti-inflamatorni agens koji se koristi za simptomatsko lečenje inflamacije, bola i reumatoidnih oboljenja. U ovom radu prikazani su različiti postupci dobijanja oksaprozina, njegovih derivata i detaljan opis mehanizma reakcija sinteze, kao i njegova fizička i hemijska svojstva. Pored osnovnih molekulskih osobina koje su značajne za aktivnost oksaprozina kao nesteroidnog anti-inflamatornog leka, navedeni su najznačajniji podaci SAR (eng. Structure-Activity Relationship) studije sintetisanih njegovih analoga. Istaknut je značaj oksaprozina u lečenju artritisa, njegova farmakokinetička svojstva i poređena je njegava aktivnost i sporedni efekti sa ostalim komercijalno dostupnim anti-inflamatornim lekovima.

Summary The behavior of 5,5-disubstituted hydantoin derivatives has been studied using four chromatographic systems, two normal-phase (silica gel stationary phase with ethyl acetate–toluene and acetonitrile–toluene mobile phases) and two reversed-phase (RP-18 systems with methanol–water and acetonitrile–water mobile phases). The effect of the structures of the derivatives on their retention in both normal and reversed-phase modes was investigated by use of QSRR and molecular descriptors. By means of multiple linear regressions results were interpreted in terms of understandable and physically meaningful variables. Among six models proposed, the two best were selected and tested for prediction of retention – one for normal-phase chromatography (NPC) and the other for reversed-phase chromatography (RPC). The most informative properties in the best NPC model, with similar effects on retention, are log P and valence connectivity indices. The informative properties in the best RPC model were log P and molecular weight, but the statistics was much worse than for NPC. Cross-validation indicated the best models are reliable QSRR models.

The C-13 NMR chemical shifts of the C2 carbon atom in the heteroaromatic nuclei of seventeen 5-(3- and 4-substituted arylazo)-4,6-dimethyl-3-cyano-2-pyridones were determined in deuterated DMSO solution. For quantitative assessment of the substituent effects on the C-13 NMR chemical shifts simple and extended Hammett equations and Swain-Lupton equation were used. The mode of transmission of substituent effects have been discussed in a relation to the geometry of investigated molecules. The geometry data were obtained using semiempirical MNDO-PM6 energy calculations. The observed C-13 NMR substituent chemical shifts were correlated with literature C-13 NMR data for the corresponding 3- and 4-substituted- 2',6'-dimethylazobenzenes and 3- and 4-substituted azobenzenes. A good linear dependence obtained in this way, provided a basis to discuss the influence of the ortho-methyl groups on the degree of coplanarity of azobenzene and pyridone systems, and on the efficiency of transmission of electronic substituent effect from one ring to the other one.

A series of some new pyridone arylazo dyes was synthesized from the corresponding diazonium salts and 4,6-diphenyl-3-cyano-2-pyridone using the classical reaction for the synthesis of the azo compounds. The structures of these dyes were confirmed by UV-vis, FTIR and 1H-NMR spectroscopic techniques. The solvatochromism of the dyes was evaluated with respect to visible absorption properties in various solvents. The effects of solvent dipolarity/polarizability and solvent/solute hydrogen bonding interactions were analyzed by means of the linear solvation energy relationship concept proposed by Kamlet and Taft. The 2-pyridone/2-hydroxypiridine tautomeric equilibration was found to depend on the substituents as well as on the solvents.

The rate constants for the reaction of 2-substituted cyclohex-1-eneacetic and 2-substituted phenylacetic acids with diazodiphenylmethane were determined in various aprotic solvents at 30°C. To explain the kinetic results through solvent effects, the second-order rate constants of the examined acids were correlated using the Kamlet–Taft solvatochromic equation. The correlations of the kinetic data were carried out by means of multiple linear regression analysis, and the solvent effects on the reaction rates were analyzed in terms of initial and transition state contributions. The opposite signs of the electrophilic and the nucleophilic parameters are in agreement with the well-known mechanism of the reaction of carboxylic acids with diazodiphenylmethane. The quantitative relationship between the molecular structure and the chemical reactivity is discussed, as well as the effect of the molecular geometry on the reactivity of the examined compounds. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 613–622, 2009

The aim of this investigation is the development of the optimal laboratory procedure for the synthesis of calcium and sodium citrate and the application of obtained results in a project for a semi-industrial installation for its production. These salts are used as an additive in numerous food and pharmaceutical products. Basically, they have to satisfy quality requirements, which is the reason why the procedure for their synthesis needs to be optimized in aspects of selection of reactants, their molar ratio, necessary laboratory equipment, reactant addition order, working temperature, isolation of final product from the reaction mixture, yield and product quality. A semi-industrial installation for the production of calcium and sodium citrate will be projected on the basis of the results of this investigation. The importance of this investigation is the fact that these salts are not produced in our country and the entire quantity (about 20 t per year) is imported. Kalcijum- i natrijum-citrat se koriste u prehrambenoj i farmaceutskoj industriji kao regulatori kiselosti, emulgatori, stabilizatori itd. Ove soli se ne proizvode u našoj zemlji i sva potrebna količina (oko 20 tona godišnje) se uvozi. Cilj ovog rada je da se izvrši optimizacija postupka sinteze kalcijum- i natrijum-citrata na laboratorijskom nivou i da se dobijeni rezultati primene za projektovanje poluindustrijskog postrojenja za njihovu proizvodnju. Optimizacija postupka za sintezu ovih soli obuhvata: izbor reaktanata i njihovog molskog odnosa, laboratorijsku opremu, redosled dodavanja reaktanata, izbor radne temperature, izdvajanje gotovog proizvoda iz reakcione smeše, prinos i kvalitet proizvoda. Kvalitet proizvoda mora da zadovolji standarde neophodne za prehrambenu i farmaceutsku industriju. Na osnovu rezultata istraživanja ostvarenih u laboratorijskim uslovima predložena je sinteza u poluindustrijskom postrojenju za proizvodnju citrata.

Summary Binder–oxidizer interactions in rocket composite propellants can be improved using adequate bonding agents. In the present work, the effectiveness of different 1,3,5-trisubstituted isocyanurates was determined by stereo and metallographic microscopy and using the software package Image-Pro Plus. The chemical analysis of samples was performed by a scanning electron microscope equipped for energy dispersive spectrometry.

Organic solvents may appear in wastewaters and other industrial waste streams containing dyes, therefore, their photodegradation catalyzed by TiO2 should be investigated. Solvent effect on photodegradation of CI Reactive Orange 16 has been studied using simulated solar light and P-25 TiO2. Methyl, ethyl and isopropyl alcohol as well as acetone were used as solvents. Photodegradation reaction was faster in methyl than in ethyl alcohol while in water was the slowest. RO16 photodegradation efficiency and reaction rate decreased in the presence of small concentration of ethanol. Higher photodegradation efficiency was observed for higher ethanol concentration. For acetone, photodegradation decreased as concentration of acetone increased. It seems that protic solvents at higher concentrations promote reaction, while at low concentrations slow down reaction. Aprotic solvents slow down reaction. U radu je ispitivan uticaj organskih rastvarača na fotodegradaciju sintetske boje (C.I. Reactive Orange 16) u vodi u prisustvu TiO2 kao katalizatora upotrebom simulirane sunčeve svetlosti. Kao rastvarači korišćeni su metil-alkohol, etil-alkohol, izopropil-alkohol i aceton. Reakcije su izvođene kako u čistim rastvaračima tako i pri različitim odnosima rastvarač/voda. Fotodegradacija boje je praćena UV/Vis spektrofotometrijom.

A series of dual-sensitive poly(2-hydroxypropyl acrylate/itaconic acid) (P(HPA/IA)) hydrogels were synthesized and evaluated as potential highly effective antiproliferative drug delivery system. Investigated hydrophobic antiproliferative agent, Ni(II) complex with Oxaprozin, was successfully synthesized and efficiently loaded into the’”intelligent” P(HPA/IA) hydrogels. Swelling studies showed that loaded agent did not annul pH- and temperature-sensitivity of the investigated hydrogels. In vitro antiproliferative activity of investigated complex against human cervical (HeLa) and melanoma cancer (FemX) cell lines was tested. The results of in vitro release study at different pH values confirmed synthesized hydrogels loaded with investigated complex as a highly effective pH-triggered drug delivery system for the advanced anticancer therapy as well as for the targeted treatment of intestine/colon cancers.

A novel strategy for the prediction of the transition temperature of bent-core liquid crystals (LCs) based on the combination of multi filter feature selection and group method of data handling (GMDH) type neural networks is reported. An entire set of 243 compounds was randomly divided into a training set of 207 compounds and a test set of 36 compounds. Descriptors were selected from a pool of 2D, and two pools of 2D and 3D ones, optimized by molecular mechanics (MM) and semi-empirical (SE) method. The reduction of the pool of descriptors was performed using multi filters based on chi square and v-WSH algorithm, while the final subset selection was performed by GMDH algorithm during the learning process. The obtained 2D, MM and SE GMDH models have 11, 13 and 16 descriptors, respectively, and demonstrate good generalization and predictive ability (R-2 = 0.92). The final models were subjected to a randomization test for validation purpose. Those models appear to be not only suitable for prediction, but they also allow the identification of key structural features that alter the transition temperature of bent-core LCs.

The rate constants for the reaction of 2-methyl-cyclohex-1-enylcarboxylic, 2-phenylcyclohex-1-enylcarboxylic, and 2-methylbenzoic and 2-phenylbenzoic acids with diazodiphenyl-methane were determined in 14 various solvents at 30 ◦ C. To explain the ki- netic results through solvent effects, the second-order rate constants of the examined acids were correlated using the Kamlet-Taft solvatochromic equation. The correlations of the ki- netic data were carried out by means of multiple linear regression analysis, and the solvent effects on the reaction rates were analyzed in terms of initial and transition state contributions. The quantitative relationship between the molecular structure and the chemical reactivity has been discussed, as well as the effect of geometry on the reactivity of the examined molecules. The geometric data of all the examined compounds corresponding to the energy minima in solvent, simulated as dielectric continuum, obtained using semiempirical MNDO-PM3 energy calculations. C

Cancer is the major health problem affecting the mankind of today. Most of the drugs used in traditional chemotherapy are very limited and the discovery of novel, more active, more selective and less toxic ones is still very intensive. A chemometric approach was applied in the study of antiproliferative activity against human colon cancer and breast cancer as well as in the study of lipophilicity of 3-(4-substituted benzyl)-5-ethyl-5-phenyl- and 3-(4-substituted benzyl)- 5,5-diphenylhydantoins. Hierarchical clustering analysis (HCA) shows that the investigated hydantoins have higher antiproliferative activity against human breast cancer cells than against human colon cancer cells. However, some hydantoins at the highest applied concentration reverse antiproliferative effect, higher against the human colon cancer cells and lower against human breast cancer cells. Principal component analysis (PCA) gives better insight into the activity of hydantoins related to their structural changes. It distinguishes more active compounds from the less active ones according to various criteria. Generally, more lipophilic 5,5-diphenylhydantoins exhibit a higher antiproliferative activity comparing to less lipophilic 5-ethyl-5-phenylhydantoins. Also, a substituent attached to benzyl moieties affects the activity additionally. The activity is particularly pronounced for compounds with cyano, methyl, chloro and bromo group. Halogen substituent were superior in antiproliferative capacity particularly in the series of 5,5-diphenylhydantoins.