Synthesis, characterization and biological study of new dinuclear zinc(ii) and nickel(ii) octaaza macrocyclic complexes

Two new nitrato complexes of zinc and nickel with 1,4,8,11-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane (tpmc), have been synthesized and characterized. The IR spectral peaks showed that the coordinated and ionic nitrate ions are in agreement with the formula proposed by elemental analysis. Conductometric titrations predicted methanol to be a convenient solvent for synthesis and revealed the stoichiometry of the complexes, while molar electrical conductivities indicated a 1 : 3 complex electrolyte type for the zinc complex, and a 1 : 2 complex electrolyte type for the nickel complex. The optimized complex structure was obtained by molecular modeling and density functional theory calculations. The biological activity of the novel complexes was examined by screening eight different bacterial strains and two cancer cell lines. The zinc complex showed better antimicrobial activity against the bacterial strains, while the complexes did not show significance antiproliferative activity toward cancer cells MCF-7 and MDA-MB-231

Molecular evidence of q fever agent coxiella burnetii in ixodid ticks collected from stray dogs in Belgrade (Serbia)

Q fever is a zoonotic disease caused by Coxiella burnetii, a gram-negative coccobacillus, which has been detected in a wide range of animal species, mostly domestic ruminants, but also in wild mammals, pets, birds, reptiles, arthropods (especially ticks), as well as in humans. Although the exposure to domestic animals in rural areas is regarded as the most common cause of the disease in humans, recent studies have shown that the role of pets in the epidemiology of Q fever has been increasingly growing. Although the primary route of infection is inhalation, it is presumed that among animals the infection circulates through ticks and that they are responsible for heterospecific transmission, as well as spatial dispersion among vertebrates. The aim of this study was to determine the presence and prevalence of C. burnetii in ticks removed from stray dogs, as well as to examine the distribution of tick species parasitizing dogs on the territory of Belgrade city. A PCR protocol targeting IS1111 repetitive transposon-like region of C. burnetii was used for the detection of C. burnetii DNA in ticks and the results were confirmed by sequence analysis. In total, 316 ticks were collected from 51 stray dogs - 40 females (78.43%) and 11 males (21.57%). Three species of ticks were identified: Rhipicephalus sanguineus (72.15%), Ixodes ricinus (27.53%) and Dermacentor reticulatus (0.32%). Out of 316 examined ticks, C. burnetii DNA was detected only in the brown dog tick R. sanguineus, with a total prevalence of 10.53% (24/228). The high prevalence of C. burnetii in R. sanguineus, which is primarily a dog tick, indicates the importance of dogs in the epidemiology of Q fever in the territory of Belgrade

The investigation of the presence of Clostridium botulinum spores in honey in Serbia

The presence of Clostridium botulinum spores in 59 honey samples originating from different regions of the Republic of Serbia was studied. In addition to microbiological methods, after enrichment, centrifugation and membrane filtration, molecular methods (PCR methods) were utilized. The number of spores in PCR positive samples was estimated by the most probable number (MPN) method. PCR confirmed C. botulinum spores in 5 (8.47%) honey samples. MPN of spores varied from 20/kg to 204/kg honey. PCR was more sensitive than cultural methods. Natural honey contamination with C. botulinum spores is low-level and not homogeneous, and therefore, PCR methods require multiple sub-sampling

Comparative studies on osmosis based encapsulation of sodium diclofenac in porcine and outdated human erythrocyte ghosts

The objective of our study was to develop controlled drug delivery system based on erythrocyte ghosts for amphiphilic compound sodium diclofenac considering the differences between erythrocytes derived from two readily available materials - porcine slaughterhouse and outdated transfusion human blood. Starting erythrocytes, empty erythrocyte ghosts and diclofenac loaded ghosts were compared in terms of the encapsulation efficiency, drug releasing profiles, size distribution, surface charge, conductivity, surface roughness and morphology. The encapsulation of sodium diclofenac was performed by an osmosis based process - gradual hemolysis. During this process sodium diclofenac exerted mild and delayed antihemolytic effect and increased potassium efflux in porcine but not in outdated human erythrocytes. FTIR spectra revealed lack of any membrane lipid disorder and chemical reaction with sodium diclofenac in encapsulated ghosts. Outdated human erythrocyte ghosts with detected nanoscale damages and reduced ability to shrink had encapsulation efficiency of only 8%. On the other hand, porcine erythrocyte ghosts had encapsulation efficiency of 37% and relatively slow drug release rate. More preserved structure and functional properties of porcine erythrocytes related to their superior encapsulation and release performances, define them as more appropriate for the usage in sodium diclofenac encapsulation process

Synthesis of substituted 3-cyano-2-pyridones: Part III - Enzyme kinetics

Lipases from Candida cylindracea and hog pancreas have been used to study the reaction kinetics of enzyme catalysed synthesis of substituted 3-cyano-2-pyridones by cyclization of 1,3-diketones with cyanoacetamide. Influence of diketone:cyanoacetamide ratio, enzyme:substrate ratio, temperature, organic media, type of enzyme and alkyl substituents on the reaction is reported. Kinetics for allosteric enzymes is indicated and apparent rate constants are calculated. However, the activation parameters obtained are more compatible with the Henry-Michaelis-Menten approach and the corresponding kinetics is also discussed

Alkilovanje n-supstituisanih 2-fenilacetamida

Various N-substituted phenylacetamides were alkylated using different alkylating agents under neutral and basic conditions. Reactions were performed at different reaction temperatures and in various solvents. Also, a number of various catalysts were used including phase-transfer catalysts. Reactions were followed using GC or GC-MS technique and the presence as well as the yields of the alkylation products were established. Generally, the best yield and high selectivity in the studied reactions were achieved under basic conditions where in the certain cases some products, mostly N-product were obtained solely in quantitative yields.Različiti N-supstituisani 2-fenilacetamidi su alkilovani koristeći različite agense za alkilovanje u neutralnoj i baznoj sredini. Reakcije su izvođene u različitim rastvaračima i na različitim temperaturama. Korišćeni su i različiti katalizatori, uključujući međufazne katalizatore. Reakcije su praćene upotrebom GC i GC-MS tehnika. Najbolji prinosi kao i selektivnost ostvareni su pri alkilovanju N-supstituisanih 2-fenilacetamida u baznoj sredini pri čemu je N-proizvod nastao u skoro kvantitativnom prinosu

Correlation analysis of IR, H-1 NMR and UV spectral data of alkyl and aryl 4,6-disubstituted-3-cyano-2-pyridones. Part I

Spectral characteristics of the two series of previously synthesized and identified 4,6-disubstituted- 3-cyano-2-pyridones were determined, and corresponding H-1 NMR chemical shifts and IR and UV frequencies were correlated with LFER parameters. A variety of substituents were employed for both alkyl and aryl substitution, and fairly good correlations were obtained, using simple Hammett and Hammett-Taft dual parameter equations, as well as the more sophisticated multiparameter regression approaches. It was established that both polar and steric effects influence the spectra of the investigated compounds

Synthesis of substituted 3-cyano-2-pyridones: Part IV. Influence of 3-alkyl-2,4-pentanedione and N-alkyl cyanoacetamide structure on the enzyme catalyzed synthesis of substituted 3-cyano-2-pyridones

Lipase from Candida rugosa has been used to Study the influence of 3-alkyl-2,4-pentanedione and N-alkyl cyanoacetamide Structure on the enzyme catalyzed reaction of pyridone ring formation in water at 40 degrees C. Starting with 1,3-diketones and cyanoacetamides and for comparison, the expected corresponding substituted 3-cyano-2-pyridones have been synthesized by chemical methods. Bulkier substituents lower the initial reaction rate of the enzyme catalyzed reactions and consequently the yield of the corresponding pyridones. N-alkyl cyanoacctamides are more reactive in comparison to the corresponding 3-alkyl-2,4-pentanediones with respect to the obtained yields of the corresponding substituted 3-cyano-2-pyridones.

Savremena kataliza u sintezi nekih farmaceutskih sirovina i finih hemikalija

Catalysis in the synthesis of Pharmaceuticals and line chemicals nowadays becomes more and more important. Synthesis that minimizes wastes is important from the economical aspect, as well as from the environmental aspect. "Green chemistry" or "green technology" is an effort to protect the environment by increasing the efficiency of the overall synthetic processes in the chemical industry by minimizing or eliminating wasteful by-products. Modern catalytic methods in the synthesis of some Pharmaceuticals and fine chemicals are discussed such as phase-transfer catalysis, biocatalysis asymmetric catalysis and, generally, solid-phase chemistry.Kataliza u sintezi farmaceutskih sirovina i finih hemikalija sve više poprima na značaju. Sinteza koja smanjuje količinu otpadnih materija značajna je kako sa ekonomskog tako i sa ekološkog značaja. "Zelena hemija", ili "zelena tehnologija" predstavljaju pokušaj da se zaštita čovekove okoline dovede na viši nivo povećanjem efikasnosti pri izvođenju sintetskih procesa u hemijskoj industriji, smanjenjem ili eliminisanjem sporednih proizvoda. U okviru ovoga rada dat je pregled savremenih katalitičkih metoda u sintezi nekih farmaceutskih sirovina i finih hemikalija. U tom cilju dat je pregled sinteza koje uključuju primenu međufazne katalize, biokatalize asimetrične sinteze, i generalno sinteze na čvrstoj fazi

Glycidyl esters synthesis catalysed by ion-exchange resins

Ion-exchange resins not previously used for this purpose were employed to study the synthesis of glycidyl esters. The reaction was carried out both with free acids and their sodium salts. The model reaction was the synthesis of glycidyl stearate. Crude glycidyl stearate was afforded in yields greater than 90% in a nonaquous, but not anhydrous system with GC purity above 99%. The phase-transfer catalytic (PTC) mechanism is proposed for the investigated reaction