Mechanistic investigations reveal that dibromobimane extrudes sulfur from biological sulfhydryl sources other than hydrogen sulfide

Hydrogen sulfide (H₂S) has emerged as an important biological signaling molecule in the last decade. During the growth of this field, significant controversy has arisen centered on the physiological concentrations of H₂S. Recently, a monobromobimane (mBB) method has been developed for the quantification of different biologically-relevant sulfide pools. Based on the prevalence of the mBB method for sulfide quantification, we expand on this method to report the use of dibromobimane (dBB) for sulfide quantification. Reaction of H₂S with dBB results in formation of highly-fluorescent bimane thioether (BTE), which is readily quantifiable by HPLC. Additionally, the reaction of sulfide with dBB to form BTE is significantly faster than the reaction of sulfide with mBB to form sulfide dibimane. Using the dBB method, BTE levels as low as 0.6 pM can be detected. Upon use of the dBB method in wild-type and CSE^–/– mice, however, dBB reports significantly higher sulfide levels than those measured using mBB. Further investigation revealed that dBB is able to extract sulfur from other sulfhydryl sources including thiols. Based on mechanistic studies, we demonstrate that dBB extracts sulfur from thiols with α- or β-hydrogens, thus leading to higher BTE formation than from sulfide alone. Taken together, the dBB method is a highly sensitive method for H₂S but is not compatible for use in studies in which other thiols are present.     

Synthesis and study of thioglycoside conjugates of 4-chloro-1,2-dithiol-3-one as potential cancer-preventive substances in vitro and in vivo

Russian Chemical Bulletin - Nucleophilic substitution of the chlorine atom in 4,5-dichloro-1,2-dithiol-3-one using 1-thio-β-d-glucopyranose and its 2,3,4,6-tetra-O-acetyl derivative in...     

Magnetically separable biocatalysts based on glucose oxidase for d-glucose oxidation

Russian Chemical Bulletin - Biocatalytic systems based on glucose oxidase immobilized on the surface of magnetically separable oxides SiO2 and Al2O3 were studied. Silicon and aluminum oxides...     

Cathodic Reduction of Zinc Oxide in Alkaline Electrolyte

Russian Journal of Electrochemistry - The reduction of zinc oxide in a limited volume of the alkaline electrolyte is studied. Methods of chronopotentiometry, chronoamperometry, and...     

Synthesis and study of interconversions of new indoline spiropyrans based on 4-hydroxy-3,5-diformylbenzoic acid

The synthesis of new indoline spiropyran by the cyclocondensation in methanol revealed that the free aldehyde group of the target spiropyran is easily converted into the dimethyl acetal moiety without the addition of an acid catalyst, giving 8′-dimethoxymethyl-1,3,3-trimethylspiro[indoline-2,2′-2H-chromene]-5,6′-dicarboxylic acid as a single reaction product. The structure of this compound was confirmed by NMR spectroscopy and mass spectrometry. The molecular structure was also established by single-crystal X-ray diffraction. The Hirshfeld surfaces were generated and analyzed and intermolecular interactions in the crystal were investigated using the CrystalExplorer software package. The reverse hydrolysis reaction of dimethyl acetal to the aldehyde group proceeds under mild conditions in dimethyl sulfoxide, as shown by NMR spectroscopy.

     

Synthesis,Structure, and Biological Activity of N-p-(Dimethylamino)-N′-(p-dimethylaminobenzylidene)-N,N′′-diphenylbenzohydrazonohydrazide

Russian Journal of General Chemistry - A three-component reaction of 3,5-diacetyl-2,6-dimethylpyridine, p-N-dimethylaminobenzaldehyde and phenylhydrazine in the presence of KOH in ethanol gave the...