Physico-chemical characterization of mixed-ligand complexes of Mn(III) based on the acetylacetonate and maleic acid and its hydroxylamine derivative

Two new Mn(III) mixed-ligand complexes with two acetylacetonate (acac) ligands and one maleate ligand and its hydroxylamine derivative of the general formula [Mn(C5H7O2)2L] were prepared. Their structure was established by using elemental analysis, FTIR and UV/VIS spectroscopic methods, as well as magnetic measurement. Replacement of the acetylacetonate ligand by the corresponding acid ligand has been confirmed in Mn(III) acetylacetonate. Based on the obtained experimental data and literature indications, structural formulae to these compounds were assigned

Продукција антибиотика помоћу Streptomyces hygroscopicus CH-7 у хранљивим подлогама са комплексима шифових базa

Influence of a modified media on Hexaene H-85 and Azalomycine B production by Streptomyces hygroscopicus CH-7 was investigated. The amino acid L-tryptophan, as a nitrogen source, was replaced with isatin-3-thiosemicarbazone and its complexes with some divalent metal ions. Isatin-3-thiosemicarbazone was synthesized in crude glycerol obtained as a byproduct in biodiesel production from sunflower oil. The complexes were charac-terized by elemental microanalysis and magnetic susceptibility, as well as, by Atomic absorption(AA), Fourier-transform infrared (FTIR) and Ultraviolet–visible (UV/VIS) spectro-scopic methods. The spectral studies indicated an octahedral geometry for the Mn(II), Fe(II) and Ni(II) complexes and a tetrahedral one for the Zn(II) complex. Comparing to the basal medium, isatin-3-thiosemicarbazone (ITC) and its metal complexes in the concentration of 0.5 g dm-3 showed better results in the antibiotics production. Use of medium supple-mented with the Fe(II) complex resulted in the maximum Hexaene H-85 and Azalomycine B concentrations of 306 μg cm-3 and 127 μg cm-3, respectively. Addition of ITC and its complexes changed the morphology of S. hygroscopicus CH-7 from filaments to pellets as a dominant shape in media resulting in higher antibiotic production.У раду је испитиван утицај модификованих хранљивих подлога на производњу антибиотика Hexaene H-85 и Azalomycine B помоћу Streptomyces hygroscopicus CH-7. Аминокиселина L-триптофан, као извор азота, замењена је изатин-3-тиосемикарбазоном (синтетисаним у сировом глицеролу који се добија као нуспродукт у производњи биодизела из сунцокретовог уља) и његовим комплексима са неким двоалентним металним јонима. Комплекси су карактерисани елементарном микроанализом, магнетном сусцептибилнош-ћу, атомском аспорпцијом (A), инфрацрвеним (IR) и ултравиолетним (UV/VIS) спектроскопским методама. Спектралне анализе показале су октахедралну геометрију комплекса Мn(II), Fе(II) и Ni(II) и тетраедарску за комплекс Zn(II). Изатин-3-тиосемикарбазон и његови комплекси са металима (0,5 g dm-3) утичу на повећање продукције антибиотика у поређењу са основном подлогом. Највеће концентрације антибиотика Hexaene H-85 и Azalomycine B су остварене у хранљивој подлози са Fe(II) комплексом (306 и 127 μg cm-3, редом). Комплекси ИТС и изатин 3-тиосемикарбазон утичу и на морфологију тестираног соја. Streptomyces hygroscopicus CH-7 растe у облику филамената и пелета, у подлогама у којима је остварена највећа продукција антибиотика

The impact of Schiff bases on antibiotic production by Streptomyces hygroscopicus

A media consisting of isatin-Schiff bases (isatin-3-thiosemicarbazone, isatin-3-semicarbazone, and isatin-3-phenylhydrazone) was developed to maximize the production of antibiotics Hexaene H-85 and Azalomycine B by Streptomyces hygroscopicus. The media isatin-3-thiosemicarbazone resulted in the maximum antibiotics concentration of 372 μg cm-3 for Hexaene H-85 and 118 μg cm-3 for Azalomycine B. The impact of modified media on soil morphology also was investigated

Sirovi glicerol i surutka kao izvori ugljenika i azota za produkciju antibiotika

The microorganisam Streptomyces hygroscopicus CH-7 produces antibiotics Hexaene, Nigericine and Elaiophyline. The yield of antibiotics can be increased by changing the fermentation conditions and the composition of the nutrient medium. Based on the previous research with this strain and the literature reviewed, the aim of this work was to study the possibility of using waste materials (whey with proteins in varying ammounts and crude glycerol from the biodiesel production) as a carbon and nitrogen source in order to increase the yeald of antibiotics produced by Streptomyces hygroscopicus CH-7. The maximum concentration of Hexaene (47,2 μg/ cm3) was achieved in the medium with whey containing 80% of protein and glycerol from sunflower oil, while the maximum concentration of Elaiophyline (24,3μg/cm3) was achived in the basal medium.Mikroorganizam Streptomyces hygroscopicus CH-7 produkuje antibiotike Heksaen, Nigericin i Elaiofilin. Promenom uslova fermentacije i sastava hranljive podloge može se povećati produkcija antibiotika. Na osnovu dosadašnjih istraživanja sa ovim sojem i literaturnog pregleda, cilj ovog rada je bio da se ispita mogućnost primene otpadnih sirovina (surutke sa različitim procentom proteina i sirovog glicerola iz proizvodnje biodizela) kao izvora ugljenika i azota, kako bi se povećala produkcija antibiotika pomoću Streptomyces hygroscopicus CH-7. Maksimalna koncentracija Heksaena (47,2 μg/cm 3) postignuta je na podlozi sa surutkom (koja sadrži 80% proteina) i glicerolom iz suncokretovog ulja, dok je maksimalna koncentracija Elaiofilina (24,3μg/cm3) ostvarena na osnovnoj podlozi

The use of salicylaldehyde derivatives as a nitrogen source for antibiotic production by Streptomyces hygroscopicus CH-7

In the present work, four derivatives of salicylaldehyde (salicylaldehyde-hydrazone, phenylhydrazone, semicarbazone and thiosemicarbazone) were synthesized using both conventional (95% ethanol) and green (crude glycerol from biodiesel production) solvents. The obtained compounds were identified by elemental microanalysis, as well as FTIR, UV/Vis and H-1-NMR spectroscopic methods. Yields of 93-98% of the compounds in crude glycerol were achieved within 10-25 min. The derivatives of salicylaldehyde and crude glycerol were used as a nitrogen and carbon source, respectively, in the medium for antibiotic (hexaene H-85 and azalomycine B) production by Streptomyces hygroscopicus CH-7. The highest concentrations of hexaene H-85 and azalomycine B were achieved in the medium containing salicylaldehyde-thiosemicarbazone (198 and 69 mu g/cm(3), respectively). Derivatives of salicylaldehyde also impacted the strain morphology. In the media with salicylaldehyde- phenylhydrazone and salicylaldehyde-thiosemicarbazone, S. hygroscopicus CH-7 grew like large dispersive pellets with long twisted filaments that produced the highest yield of the antibiotics

The physicochemical and thermodynamic properties of the choline chloride-based deep eutectic solvents

This paper reports the physicochemical (density, dynamic viscosity, electrical conductivity and refractive index) and the thermodynamic (thermal expansion coefficient, molecular volume, lattice energy and heat capacity) properties of several choline chloride (ChCl) based deep eutectic solvents (DESs), with 1:2 mole ratio, respectively:ChCl:propylene glycol, ChCl:1,3-dimethyl-urea and ChCl:thiourea, at atmospheric pressure as a function of temperature over the range of 293.15-363.15 K. Their properties were also compared with those of some already characterized ChCl-based DESs, namely ChCl:ethylene glycol, ChCl:glycerol and ChCl:urea (1:2 mole ratio). Density, viscosity and refractive index of all DESs decrease with the increasing temperature while the electrical conductivity increases. Viscosity and conductivity of the tested DESs were fitted by both Arrhenius-type and Vogel-Tamman-Fulcher equations. The changes of molar enthalpy, entropy and Gibbs energy of activation, determined using the Eyring theory, demonstrated the interactional factor as predominant over the structural factor for all DES systems. The fractional Walden rule, used to correlate molar conductivity and viscosity, showed an excellent linear behaviour. It was shown that ChCl:propylene glycol DES had properties similar to ChCl:ethylene glycol and ChCl:glycerol DESs. However, the properties (density, viscosity and electrical conductivity) of ChCl:1,3-dimethylurea and ChCl::thiourea DESs were inferior to those of the ChCl:urea DES

POPULATION PHARMACOKINETICS OF 2-OXO-CLOPIDOGREL IN PATIENTS WITH ACUTE CORONARY SYNDROME

The aim of the study was to develop a population pharmacokinetic (PK) model for clearance of 2-oxo-clopidogrel in patients with acute coronary syndrome (ACS). Population pharmacokinetic analysis was performed by using 72 plasma concentrations from the same number of patients (mean age of 60.82±10.76 years; total body weight (TBW) of 73.63±9.67 kg) with ACS using non-linear mixed-effect modeling (NONMEM). Validation of the final PPK model was carried out through the bootstrap analysis with 200 runs and it was used to estimate the predictive performance of the pharmacokinetic model. The typical mean value for 2-oxo-clopidogrel clearance (CL), estimated by the base model (without covariates), in our population was 39.2 l h−1.The value of aspartate transaminase and co-medication with digoxin were determinants of a derived population model. The final regression model for the clearance of 2-oxo-clopidogrel was the following: CL (lh-1) = 1.7 + 1.31*AST + 115*DIGOXIN. The derived PK model describes the clearance of 2-oxo-clopidogrel in patients with ACS, showing that the value of aspartate transaminase and co-medication with digoxin are the most important covariate. This finding will provide the basis for future PK studies

Second Generation Steroidal 4-Aminoquinolines Are Potent, Dual-Target Inhibitors of the Botulinum Neurotoxin Serotype A Metalloprotease and P. falciparum Malaria

Significantly more potent second generation 4-amino-7-chloroquinoline (4,7-ACQ) based inhibitors of the botulinum neurotoxin serotype A (BoNT/A) light chain were synthesized. Introducing an amino group at the C(3) position of the cholate component markedly increased potency (IC50 values for such derivatives ranged from 0.81 to 2.27 mu M). Two additional subclasses were prepared: bis(steroidal)-4,7-ACQ derivatives and bis(4,7-ACQ)cholate derivatives; both classes provided inhibitors with nanomolar-range potencies (e.g., the K-i of compound 67 is 0.10 mu M). During BoNT/A challenge using primary neurons, select derivatives protected SNAP-25 by up to 89%. Docking simulations were performed to rationalize the compounds' in vitro potencies. In addition to specific residue contacts, coordination of the enzyme's catalytic zinc and expulsion of the enzyme's catalytic water were a consistent theme. With respect to antimalarial activity, the compounds provided better IC90 activities against chloroquine resistant (CQR) malaria than CQ, and seven compounds were more active than mefloquine against CQR strain W2

Correlation between the structure and biological activity of some coordination compounds of isatin Schiff bases

The complexes of Co(ll), Ni(ll), Cu(ll) and Zn(ll) with isatin Schiff bases were synthetised and their structures established by using elemental analysis, as well as by measuring the molar conductivity, AA, FTIR, UV/VIS and 1H NMR and applying TG analysis.Isatin Schiff bases show different antimicrobial activity due to the different nature of the carbonyl and amino components as well as its substituent. The complexes have an enhanced activity compared to the ligands due to the transition metal involved in the coordination. It is also evident that the complexeshave different antimicrobial activity, which is related to the nature and typeof coordinated metal

SYNTHESIS, X-RAY AND ANTIMICROBIAL ACTIVITY OF ISATIN-3-PHENYLHYDRAZONE

Isatin-3-phenylhydrazone was synthesized and X-ray crystal structure of this compound has been solved. Its structure was also established using FTIR, UV/Vis and 1H-NMR spectroscopic method. The compound was tested for antimicrobial activity against Staphylococcus aureus, Bacillus subtilus, Enterococcus D, Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa and Candida albicans. Stability of isatin-3-phenylhydrazone toward UV-A irradiation has been studied in this work. Isatin derivative undergoes bleaching following first-order kinetics