Synthesis, Crystal Structures, Lipophilic Properties and Antimicrobial Activity of 5-Pyridylmethylidene-3-rhodanine-carboxyalkyl Acids Derivatives.

The constant increase in the resistance of pathogenic bacteria to the commonly used drugs so far makes it necessary to search for new substances with antibacterial activity. Taking up this challenge, we obtained a series of rhodanine-3-carboxyalkyl acid derivatives containing 2- or 3- or 4-pyridinyl moiety at the C-5 position. These compounds were tested for their antibacterial and antifungal activities.

Evaluation of the effectiveness of iodine prophylaxis in Poland based on over 20 years of observations of iodine supply in school-aged children in the central region of the country.

Introduction: Due to the mild-to-moderate iodine deficiency in Poland, in 1997 iodine prophylaxis based on obligatory salt iodization was introduced. We attempted to evaluate the effectiveness of such prophylaxis, based on over 20 years of observations of iodine supply in school-aged children in Opoczno district (Central Poland).

Material And Methods: A group of 603 children (316 girls and 287 boys), aged 6-14, was examined at 4 time points: in the years 1994, 1999, 2010 and 2016.

Determination of nikethamide by micellar electrokinetic chromatography.

A simple, fast, sensitive and reproducible micellar electrokinetic chromatography (MEKC)-UV method for the determination of nikethamide (NKD) in human urine and pharmaceutical formulation has been developed and validated. The method exhibits high trueness, good precision, short analysis time and low reagent consumption. NKD is an organic compound belonging to the psychoactive stimulants used as an analeptic drugs.

Chromatographic and Computational Studies of Molecular Lipophilicity and Drug-likeness for few 2-Thioxo-1,3-Thiazolidin-4-one Derivatives and their Analogs.

Hydrophobicity of the eight 2-thioxo-1,3-thiazolidin-4-one derivatives was determined experimentally by thin-layer chromatography and predicted by means of commercially available programmers. RM values were determined by reversed-phase thin-layer chromatography with using acetonitrile-water, methanol-water, acetone-water, propan-2-ol-water or 1,4-dioxane-water and compared with logP values calculated by using computer programs: HyperChem 8.0.

A derivatization approach using pyrylium salts for the sensitive and simple determination of sulfide in spring water by high performance liquid chromatography.

A high-performance liquid chromatography method based on pre-column derivatization with the pyrylium salts (4-[p-(N,N-dimethylamino)phenyl]-2,6-diphenylpyrylium perchlorate (LN1) and 2,4,6-triphenylpyrylium tetrafluoroborate (L1)) has been developed for the determination of sulfide. After the reaction of sulfide ions with LN1 or L1 aiming at the formation of the corresponding thiopyrylium derivatives LN3 or L3, they were separated on a C18 column using phosphate buffer and acetonitrile as eluent, and afterwards detected with a UV/vis detector. By using the described method, sulfide ions can be determined in the range of 5.

Application of Purpald® for determination of 3-cyclohexene-1-carboxaldehyde and hydroxyisohexyl 3-cyclohexene carboxaldehyde.

A spectrophotometric method for determination of 3-cyclohexene-1-carboxaldehyde and hydroxyisohexyl 3-cyclohexene carboxaldehyde was developed. This procedure is based on the reaction of carbonyl compounds with the selective derivatization reagent Purpald® in alkaline solution. The product of reaction is a colored compound with maximum absorption at 538 nm.

Determination of urinary 6-mercaptopurine and three of its metabolites by HPLC-UV coupled with the iodine-azide reaction.

Background: The presented method is able to determine 6-mercaptopurine (6-MP), 6-thioguanine, 6-mercaptopurine riboside and 6-thioguanine riboside in urine, and is thereby dedicated to control of thiopurine therapy of children with acute lymphoblastic leukemia. Good separation of the mentioned compounds was achieved on a C18 stationary phase with a sodium azide and sodium heptane sulfonate solution, acetonitrile and water at ratio of 50:1:49 (v/v/v).

Results: Coefficient of regression is >0.

The use of a new, modified Dittmer-Lester spray reagent for phospholipid determination by the TLC image analysis technique.

A new phospholipid-specific spray reagent is described. A new phospholipid-specific spray reagent, which is a modification of the Dittmer-Lester reagent, is described in authors' studies. The difference between these two reagents is in the addition of tin (II) chloride to the proposed spray reagent.

RP-HPLC-UV method coupled with post-column iodine-azide reaction for determination of free captopril in urine samples.

Background: A free urinary captopril is measured indirectly employing the iodine-azide reaction in post-column mode. The pre-clean-up and/or derivatization step is needless, so that the method is adequate for rapid captopril determination in the urine samples and its monitoring at clinical trial. Captopril is separated on a C4 column by the eluate composed of sodium azide solution (4% [w/v], pH 5.

Determination of propylthiouracil in pharmaceutical formulation by high-performance liquid-chromatography with a post-column iodine-azide reaction as a detection system.

A high-performance liquid chromatographic method with a post-column iodine-azide reaction has been chosen and tested for validity in quantitative determination of propylthiouracil in tablets. A mobile phase with a flow rate of 1.4 ml/min was conducted in the form of isocratic chromatography on a C18 column with acetonitrile-water-sodium azide solution (2.

Application of the iodine-azide postcolumn reaction in RP-HPLC for the determination of thioguanine in urine.

The study focuses on the analysis of a sensitive, selective, and simple postcolumn detection method for thioguanine determination, based on the sensitizing induction of thioguanine on iodine-azide reaction and the combination technique of HPLC. The analysis was accomplished in the optimum conditions for iodine-azide detection system and HPLC separation. The values for the linear range, the LOD, and DOQ amounted to 0.

High-performance liquid chromatographic determination of propylthiouracil in human urine by post-column iodine-azide reaction.

A sensitive, selective and simple post-column detection method for the determination of propylthiouracil (PTU) based on its sensitizing induction on iodine-azide reaction and the combination technique of high-performance liquid chromatography has been presented. The analysis was conducted in the optimum conditions for iodine-azide detection system and HPLC separation. The linear range, the lower limit of detection and quantification for PTU in urine were established at the levels of 0.

Determination of methimazole in urine with the iodine-azide detection system following its separation by reversed-phase high-performance liquid chromatography.

The iodine-azide detection system to determine methimazole following its separation by RP-HPLC is described in this paper. The reaction between iodine and azide ions induced by methimazole was applied as a post-column reaction detection system. Neither extraction nor preconcentration of the sample was necessary.

Direct determination of metformin in urine by adsorptive catalytic square-wave voltammetry.

A new adsorptive catalytic voltammetric method for voltammetric determination of metformin based on the catalytic hydrogen evolution reaction at a hanging mercury drop electrode was developed. The electrode reaction was analyzed under conditions of linear sweep voltammetry (LSV), differential pulse voltammetry (DPV) and Osteryoung-type square-wave voltammetry (SWV). The peak current depends on pH of the medium, concentration and chemical composition of the buffer solution, and instrumental parameters.

Determination of thiopental in urine sample with high-performance liquid chromatography using iodine-azide reaction as a postcolumn detection system.

The reaction between iodine and azide ions induced by thiopental was utilized as a postcolumn reaction for chromatographic determination of thiopental. The method is based on the separation of thiopental on an Nova-Pak CN HP column with an acetonitrile-aqueous solution of sodium azide as a mobile phase, followed by spectrophotometric measurement of the residual iodine (lambda=350 nm) from the postcolumn iodine-azide reaction induced by thiopental after mixing an iodine solution containing iodide ions with the column effluent containing azide ions and thiopental. Chromatograms obtained for thiopental showed negative peaks as a result of the decrease in background absorbance.

Detection of mercaptopyridines and mercaptopyrimidines in planar chromatography with iodine-azide reaction as a detection system.

Reaction between iodine and azide ion induced by mercaptopyridines and mercaptopyrimidines was utilized as a detection system in TLC and HPTLC. The developed plates were sprayed with a freshly prepared mixtures of sodium azide and starch solution adjusted to pH 5.5, and exposed to iodine vapour.

Application of iodine-azide reaction for detection of amino acids in thin-layer chromatography.

The iodine-azide reaction was employed to TLC detection of sulphur-containing derivatives of protein and some non-protein amino acids. The derivatization reaction with phenyl isothiocyanate (PITC) took place directly on the plate before the developing step. Subsequently, the plates were sprayed with a mixture of sodium azide and starch solution in NP-TLC and in the case of RP-TLC sodium azide solution with starch incorporated into mobile phase and then exposed to iodine vapour.

The lived experiences of alcohol addiction: men of alcoholics anonymous.

Alcohol addiction is one of the most prevalent and debilitating psychiatric disorders among the general population. Yet, little has been published on what it is like for men to actually experience this disorder. The purpose of this study was to identify commonalities in the experience of alcohol addiction among seven male members of Alcoholics Anonymous.

Application of improved iodine-azide procedure for the detection of thiouracils in blood serum and urine with planar chromatography.

The application of iodine-azide reaction for the determination of thiouracils in thin-layer chromatography and high-performance thin-layer chromatography is described. The developed plates were sprayed with a freshly prepared mixture of sodium azide, adjusted to a proper pH, and starch solution, and exposed to iodine vapour for 5 s. The detection limits were established at pmol level.