So far, azide has been consistently reported to act as an inhibitor of metal enzymes, especially copper proteins. The present work shows that azide can also act as an activator of polyphenol oxidase II (PPO II) from tobacco leaves. From the square-wave voltammetry of native PPO II, peroxide-PPO II complex and azide-PPO II complex, the reduction of nitro blue tetrazolium by the enzymes and activ...

In the last decades, organic azides haven proven to be very useful precursors in organic chemistry, for example in 1,3-dipolar cycloaddition reactions (click-chemistry). Likewise, azides can be introduced into graphene oxide with an almost intact carbon framework, namely oxo-functionalized graphene (oxo-G₁), which is a highly oxidized graphene derivative and a powerful precursor for graphene th...

Reaction of ethyl (Z)-3-(heteroaryl/aryl)-2-((triphenyl-λ5-phosphaneylidene) amino) acrylates intermediates with 2,3-thiophenedicarboxaldehyde was used in novel Tandem three consecutive reactions: aza-Wittig, imine condensation and electrophilic heteroaromatic cyclization to obtain a series indolizines. A tentative mechanism this reaction is proposed.

Direct incorporation of azide groups into RNA oligonucleotides by in vitro transcription reactions in the presence of a new azide-modified UTP analogue, and subsequent posttranscriptional chemical labeling of azide-modified oligoribonucleotide transcripts by click and Staudinger reactions are described. This postsynthetic labeling protocol is robust and modular, and offers an alternative access...

Unidirectional Na fluxes from frog's striated muscle were measured in the presence of 0 to 5 mM sodium azide. With azide concentrations of 2 and 5 mM the Na efflux was markedly stimulated; the Na efflux with 5 mM azide was about 300 per cent greater than normal. A similar increase was present when all but the 5.0 mM sodium added with azide was replaced by choline. 10(-5)M strophanthidin abolish...

Sodium azide activated soluble rat liver guanylate cyclase but not crude preparations from rat heart or bovine lung. Mixing supernatant fractions from liver preparations with those from heart or lung resulted in an inhibition of sodium azide activation. The inhibitory activity was nondialyzable, heat-labile, and resistant to trypsin treatment. Chromatography of heart or lung supernatant prepara...

An intramolecular Huisgen cycloaddition of an interconverting set of isomeric allylic azides with alkynes affords substituted triazoles in high yield. The stereoisomeric vinyl-substituted triazoloxazines formed depend on the rate of cycloaddition of the different allylic azide precursors when the reaction is carried out under thermal conditions. In contrast, dimerized macrocyclic products were ...

A method for the palladium-catalyzed arylation of α,β-unsaturated valerolactams is reported. This new protocol provides arylation products in yields up to 95% and is applicable to a wide array of aryl and heteroaryl bromides. The optimization, scope and limitations are described.