Electrosynthesis of anisidines in aqueous sulfuric and acetic acids

The influence of the concentrations of acetic and sulfuric acids on the efficiency of anisole amination by means of hydroxylamine and Ti(IV)/Ti(III) mediator was studied. Ortho- and para-anisidines were obtained with the total yields of about 79% by current and hydroxylamine. © 2009 Pleiades Publishing, Ltd

Electrochemical amination. Dilute aqueous organic solutions of sulfuric acid

The electrochemical process of anisole amination is studied in 1.5-9 M H2SO4 solutions containing acetonitrile or acetic acid. It is shown that the synthesis of aromatic monoamino compounds is better performed in moderately acidic media with high concentrations of organic solvents. Due to the chain mechanism of the electrochemical process, the current efficiency of amines can exceed 150% under these conditions. © 2009 Pleiades Publishing, Ltd

Coulometric determination of sulfur-containing amino acids using halogens as oxidizing titrants

It is found that cysteine and methionine quantitatively react with electrogenerated halogens under the conditions of galvanostatic coulometry. Cysteine reacts with all titrants, and methionine reacts only with chlorine and bromine. The stoichiometric coefficients of reactions between cysteine and halogens are 1:3, 1:3, and 1:1 for chlorine, bromine, and iodine, respectively. These coefficients for methionine reactions with chlorine and bromine are 1:2 and 1:1, respectively. It is shown that cysteine can be selectively determined in its mixtures with methionine by coulometric titration with electrogenerated iodine. It is found that twofold amounts of methionine do not interfere with the determination of cysteine. A procedure is developed for the direct coulometric determination of methionine in tablets with a relative standard deviation of 3-5%. © 2007 Pleiades Publishing, Ltd

Electrochemical determination of unithiol and lipoic acid at electrodes modified with carbon nanotubes

Conditions are found for the voltammetric determination of lipoic acid and unithiol at a glassy-carbon electrode modified with multiwalled carbon nanotubes. Possible mechanisms for the oxidation of lipoic acid and unithiol are proposed. As compared to an unmodified electrode, the use of the modified electrode allows the analyst to reduce overvoltage (ΔE = 0.1 V) and increase the oxidation current of lipoic acid. Unithiol is oxidized in the accessible range of potentials only at an electrode modified with carbon nanotubes. The determination limits for unithiol and lipoic acid are 4.1 × 10-5 and 1.9 × 10-5 M, respectively. Milligram amounts of these substances are determined in model solutions with RSD = 1-5%. Procedures for determining the active substances (lipoic acid and unithiol) in pharmaceuticals are proposed. © 2009 Pleiades Publishing, Ltd

Esterification of betulin with ω-bromoalkanoic acids

© 2015 Pleiades Publishing, Ltd. New C3- and C28-functionalized derivatives of the lupane triterpenoid betulin have been synthesized by esterification with ω-bromoalkanoic acids, and preliminary biological screening of the obtained compounds has been performed

Electrochemical oxidation of sulfur-containing amino acids on an electrode modified with multi-walled carbon nanotubes

MWNT-modified electrodes are introduced for the voltammetric determination of sulfur-containing amino acids. The morphology of the electrode surface has been characterized by atomic force microscopy. The MWNT layer consists of deeply intertwined vermicular structures with the average diameter of 25 nm. Cysteine, glutathione and methionine are oxidized on the electrode while only cysteine gives signals on the glassy carbon (GC) electrode. The application of such electrodes leads to a decreased overpotential and increase of oxidation currents for cysteine in comparison with a bare GC electrode. The schemes of oxidation are proposed. A decrease of the lower limit of determination and an enlargement of the analytical range for antioxidants were obtained. A simple, fast and accurate procedure for the voltammetric determination of methionine in pharmaceuticals has been developed and can be recommended for quality control purposes. © 2009 Springer-Verlag

Design, Synthesis, and Cancer Cell Growth Inhibitory Activity of Triphenylphosphonium Derivatives of the Triterpenoid Betulin

© 2017 The American Chemical Society and American Society of Pharmacognosy. A series of new triphenylphosphonium (TPP) derivatives of the triterpenoid betulin (1, 3-lup-20(29)-ene-3β,28-diol) have been synthesized and evaluated for cytotoxic effects against human breast cancer (MCF-7), prostate adenocarcinoma (PC-3), vinblastine-resistant human breast cancer (MCF-7/Vinb), and human skin fibroblast (HSF) cells. The TPP moiety was applied as a carrier group through the acyl linker at the 28- or 3- and 28-positions of betulin to promote cellular and mitochondrial accumulation of the resultant compounds. A structure-activity relationship study has revealed the essential role of the TPP group in the biological properties of the betulin derivatives produced. The present results showed that a conjugate of betulin with TPP (3) enhanced antiproliferative activity toward vinblastine-resistant MCF-7 cells, with an IC 50 value as low as 0.045 μM

The use of an antibacterial implant in the treatment of periprosthetic infection in an HIV-positive patient

Background: The frequency of occurrence of infectious complications after hip arthroplasty in HIV-infected patients is extremely high. Revision arthroplasty for periprosthetic infection is the leader (64%) among the causes of early revision interventions. The search for ways to increase the efficiency of the sanitizing stage of treatment due to antibacterial coatings of the endoprosthesis components continues.Objective: Demonstration of a clinical case of treatment of periprosthetic infection in an HIV-positive patient using a spacer and a femoral component of a hip joint endoprosthesis coated with linear Sp1 carbon chains and silver. 123 months after hip arthroplasty for stage 3 dysplastic coxarthrosis in HIV-positive patient of 42 years old developed an instability of the acetabular component with the growth of Staphylococcus aureus in punctates. A revision was performed with the removal of the endoprosthesis and the installation of an articulating spacer with the addition of antibiotics. 12 weeks later, a recurrence of periprosthetic infection occurred, and Enterococcus faecalis was detected in punctates. During re-endoprosthetics, there was an installation of an articulating spacer covered with a two-dimensionally ordered linear-chain carbon doped with silver, based on the Zimmer CPT femoral component and bone cement with antibiotics addition. After 3 months, the second stage of revision arthroplasty was performed with implantation of an individual acetabular component and a femoral component coated with two-dimensionally ordered linear-chain carbon doped with silver.Conclusion: 4 months after the operation the patient returned to work, 12 months later the functional results were satisfactory. The use of components coated with two-dimensionally ordered linear-chain carbon doped with silver in an HIV-positive patient with recurrent periprosthetic infection made it possible to stop the infectious process, improve limb function and the quality of life

РОЛЬ ПАРАЗИТАРНЫХ БОЛЕЗНЕЙ В ПАТОЛОГИИ ЧЕЛОВЕКА

Parasitic diseases cause a serious pathology. Sharp current with clinical displays mark at malaria, trichinellosis, amebiasis, leishmaniosis. Feature of the majority of parasitic diseases is their chronic current connected with long, sometimes long-term, parasiting of the agent in people that depends on life expectancy of the parasite and reinfection.Паразитарные болезни вызывают серьезную патологию. Острое течение с клиническими проявлениями отмечают при малярии, трихинеллезе, амебиозе, лейшманиозе. Особенностью большинства паразитарных болезней является их хроническое течение, связанное с длительным, иногда многолетним, паразитированием возбудителя в организме больного, что зависит от продолжительности жизни паразита и реинвазии

Ultra-High Energy Cosmic Ray production in the polar cap regions of black hole magnetospheres

We develop a model of ultra-high energy cosmic ray (UHECR) production via acceleration in a rotation-induced electric field in vacuum gaps in the magnetospheres of supermassive black holes (BH). We show that if the poloidal magnetic field near the BH horizon is misaligned with the BH rotation axis, charged particles, which initially spiral into the BH hole along the equatorial plane, penetrate into the regions above the BH "polar caps" and are ejected with high energies to infinity. We show that in such a model acceleration of protons near a BH of typical mass 3e8 solar masses is possible only if the magnetic field is almost aligned with the BH rotation axis. We find that the power of anisotropic electromagnetic emission from an UHECR source near a supermassive BH should be at least 10-100 times larger then UHECR power of the source. This implies that if the number of UHECR sources within the 100 Mpc sphere is ~100, the power of electromagnetic emission which accompanies proton acceleration in each source, $10^{42-43}$ erg/s, is comparable to the typical luminosities of active galactic nuclei (AGN) in the local Universe. We also explore the acceleration of heavy nuclei, for which the constraints on the electromagnetic luminosity and on the alignment of magnetic field in the gap are relaxed