Synthesis and Antibacterial Activity of Sulfanilamides Containing Sterically Hindered Phenol Fragments

Abstract: New sulfanilamide derivatives containing sterically hindered phenol fragments have been synthesized via modification of the amino group by reaction with 3,5-di-tert-butyl-4-hydroxybenzyl acetate and diazotization followed by diazo coupling with 2,4-di-tert-butylphenol. 4-Aminobenzenesulfonamide derivatives at the sulfonamide group have been obtained by converting acetyl-protected 4-aminobenzenesulfonyl chloride to the corresponding sulfonohydrazide and reacting the latter with 3,5-di-tert-butyl-4-hydroxybenzyl acetate, sterically hindered hydroxybenzaldehydes, and N-(3,5-di-tert-butyl-4-hydroxybenzyl)isatin. Modification of sulfanilamide with sterically hindered phenol fragments significantly increased antibacterial activity

Synthesis of hybrid compounds by benzylation of acylhydrazones with 3,5-di-tert-butyl-4-hydroxybenzyl acetate

N-Benzylation of acylhydrazones of the hydroxybenzaldehyde series with 3,5-di-tert-butyl-4-hydroxybenzyl acetate was performed at room temperature in the absence of acid or base catalysts. Carboxamides do not react with 3,5-di-tert-butyl-4-hydroxybenzyl acetate under similar conditions. N-Benzylation of isoniazid and (diphenylphosphoryl)acetic acid hydrazones was shown to be an efficient method for the synthesis of new hybrid compounds containing moieties of biologically active acylhydrazones and sterically hindered phenols. N-Benzyl derivatives of isoniazid and (diphenylphosphoryl)acetic acid hydrazones containing a hydroxy group at the ortho position of the aromatic ring are formed as individual E isomers with respect to the C-N double bond

Diagnosis of quality parameters of coal and liquid petroleum products by electromagnetic methods

Наведено результати математичного моделювання хвилевідного і резонаторного методів діагностики параметрів якості вугілля і рідких нафтопродуктів (калорійності, зольності, вологості). Розглянуто новий підхід до визначення хвилевідним методом комплексної діелектричної проникності (ДП) досліджуваної речовини, заснований на результатах вимірювання її коефіцієнта стоячої хвилі по напрузі при зондуванні у деякому частотному діапазоні. Розглянуто резонаторний метод визначення ДП рідких нафтопродуктів шляхом розміщення в трубопроводі резонаторних вимірювальних осередків. Досліджено можливість контролю якості вугілля на конвеєрі з використанням значень загасання електромагнітної хвилі, що проходить крізь шар досліджуваного вугілля. Результати досліджень запропоновано використовувати для діагностики та управління якістю цих речовин, що транспортуються на конвеєрі або по трубопроводу.The results of mathematical modeling of the waveguide and resonator methods for diagnosis of the parameters of quality of coal and liquid petroleum products (calorific value, ash, moisture). A new approach to defining the waveguide by the method of complex permittivity (CP) of the substance, based on the results of measuring its voltage standing wave ratio in probing the in some frequency range. Considered resonator method for determining the CP of liquid petroleum products by placing in the pipe cavity measuring cells. The possibility of controlling the quality of coal on the conveyor with the use of attenuation of electromagnetic waves passing through the layer under coal is study. The results of the research proposed to use for diagnostic and quality control of these substances to be transported on a conveyor belt or pipeline wire.Приведены результаты математического моделирования волноводного и резонаторного методов диагностики параметров качества углей и жидких нефтепродуктов (калорийности, зольности,влажности). Рассмотрен новый подход к определению волноводным методом комплексной диэлектрической проницаемости (ДП) исследуемого вещества, основанный на результатах измерения его коэффициента стоячей волны по напряжению при зондировании в некотором частотном диапазоне. Рассмотрен резонаторный метод определения ДП жидких нефтепродуктов путем размещения в трубопроводе резонаторных измерительных ячеек. Исследована возможность контроля качества углей на конвейере с использованием значений затухания электромагнитной волны, проходящей сквозь слой исследуемого угля. Результаты исследований предложено использовать для диагностики и управления качеством этих веществ, транспортируемых на конвейере или по трубопроводу

Laser-assisted deposition of colloidal nanoparticles for creation fractal bimetallic structures, Laser–assisted periodic nanostructure formation in dielectric materials: formation mechanisms

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Ammonium-Charged Sterically Hindered Phenols with Antioxidant and Selective Anti-Gram-Positive Bacterial Activity

© 2020 Wiley-VHCA AG, Zurich, Switzerland The increase in the resistance of pathogens, in particular Staphylococcus aureus, to the action of antibiotics necessitates the search for new readily available and non-toxic drugs. In solving this problem, phenolic acylhydrazones have high potential. In this communication, the synthesis of quaternary ammonium compounds containing a differently substituted phenolic moiety has been performed. An initial study of antimicrobial activity showed that these compounds are highly selective against S. aureus and B. cereus. The highest activity (MIC 2.0 μm) was shown by hydrazones containing a catechol fragment. These compounds are more than 3-fold more active against S. aureus and 3–10-fold more active against B. cereus than norfloxacin. Low hemolytic and high antioxidant activities of all new compounds were also established

Bi-functional sterically hindered phenol lipid-based delivery systems as potential multi-target agents against Alzheimer's disease: Via an intranasal route

© The Royal Society of Chemistry. New lipid-based nanomaterials and multi-target directed ligands (MTDLs) based on sterically hindered phenol, containing a quaternary ammonium moiety (SHP-s-R, with s = 2,3) of varying hydrophobicity (R = CH2Ph and CnH2n+1, with n = 8, 10, 12, 16), have been prepared as potential drugs against Alzheimer's disease (AD). SHP-s-R are inhibitors of human cholinesterases with antioxidant properties. The inhibitory potency of SHP-s-R and selectivity ratio of cholinesterase inhibition were found to significantly depend on the length of the methylene spacer (s) and alkyl chain length. The compound SHP-2-16 showed the best IC50 for human AChE and the highest selectivity, being 30-fold more potent than for human BChE. Molecular modeling of SHP-2-16 binding to human AChE suggests that this compound is a dual binding site inhibitor that interacts with both the peripheral anionic site and catalytic active site. The relationship between self-assembly parameters (CMC, solubilization capacity, aggregation number), antioxidant activity and a toxicological parameter (hemolytic action on human red blood cells) was investigated. Two sterically hindered phenols (SHP-2-Bn and SHP-2-R) were loaded into L-a-phosphatidylcholine (PC) nanoparticles by varying the SHP alkyl chain length. For the brain AChE inhibition assay, PC/SHP-2-Bn/SHP-2-16 nanoparticles were administered to rats intranasally at a dose of 8 mg kg-1. The Morris water maze experiment showed that scopolamine-induced AD-like dementia in rats treated with PC/SHP-2-Bn/SHP-2-16 nanoparticles was significantly reduced. This is the first example of cationic SHP-phospholipid nanoparticles for inhibition of brain cholinesterases realized by the use of intranasal administration. This route has promising potential for the treatment of AD