PubMed · 381919
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J Hope. 1979. Non-activation in the Ames test.. https://doi.org/10.1016/0165-1218(79)90133-2
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The galectins are a family of [small beta]-galactoside-binding proteins that have been implicated in cancer and inflammation processes. Herein, we report the synthesis of a library of 28 compounds that was tested for binding to galectins-1, -3, -7, -8N and -9N. An aromatic nucleophilic substitution reaction between 1,5-difluoro-2,4-dinitrobenzene and a galacto thiol gave 5-fluoro-2,4-dinitrophenyl 2,3,4,6-tetra-O-acetyl-1-thio-beta-D-galactopyranoside. This versatile intermediate was then modified in a two dimensional manner: either by further substitution of the second fluoride by amines or thiols, or by reduction of the nitro groups and acylation of the resulting amines, or both. Deacetylation then gave a library of aromatic beta-galactosides that showed variable inhibitory activity against the different galectins, as shown by screening with a fluorescence-polarisation assay. Particularly efficient inhibitors were found against galectin-7, while less impressive enhancements of inhibitor affinity over methyl beta-D-galactopyranoside were found for galectin-1, -3, -8N and -9N. The best inhibitors against galectin-7 showed significantly higher affinity (K(d) as low as 140 microM) than both beta-methyl galactoside (K(d) 4.8 mM) and the unsubstituted beta-phenyl thiogalactoside (non-inhibitory). The best inhibitors against galectin-7 were poor against the other galectins and thus have potential as structurally simple and selective tools for dissecting biological functions of galectin-7.
The reaction of enalapril maleate and lisinopril with 2,4-dinitrofluorobenzene has been used to form colored products and polarographically active derivatives. The different experimental conditions have been optimized. The proposed methods have been validated and applied to the determination of both drugs in their commercial tablets. The results have been statistically compared with those obtained using the official HPLC methods.
The feasibility of gas chromatography-mass spectrometry for the speciation of traces of dialkyldiselenides in the presence of dialkylselenides and inorganic selenium species is described, and the procedure is applied to environmental samples. The analysis is based on the reaction of dialkyldiselenide species with 1-fluoro-2,4-dinitrobenzene after volatilization of selenium species as alkylselenols using a volatilization and trap device. Parameters affecting the volatilization and derivatization of the selenium compounds are discussed, and the performance of the method is described. The approach reaches detection limits in the order of nanograms (after a preconcentration step) and has been applied to the analysis of dimethyldiselenium and diethyldiselenium in natural waters.