Nitrogen chemical biology

Asphyxiant Simple asphyxiants are inert gases which deplete the oxygen supply in the breathing air to below the critical value of J8% by volume, such as gaseous fuels or nitrogen. Chemical asphyxiants, such as carbon monoxide and hydrogen cyanide, have a direct biological effect. 

CNC A chemical/biological process for oxidizing cyanide ion in wastewater. The waste-water is mixed with a proprietary soluble reagent and passed through a biological reactor in which cyanide is oxidized to carbon dioxide and nitrogen. Developed and offered by Radian Corporation, Austin, TX. 

Many bacteria perform services we find useful and even necessary, although we rarely take note of them. Some bacteria participate in the decomposition of dead plants and animals and so help recycle chemicals that are otherwise locked away from the living world. Some are sources of antibiotics that have revolutionized the treatment of infectious disease in the past fifty years. Others are responsible for nitrogen fixation, converting relatively inert atmospheric nitrogen into biologically useful ammonia—a conversion that is not simple in the chemical laboratory. Still other bacteria are indispensable in the world s kitchens, for without them there would be no cheese or yogurt, nor any of hundreds of other traditional milk products. We could not enjoy pickles or sauerkraut, and... 

P.C. Dedon et al., Reactive nitrogen species in the chemical biology of inflammation. Arch. Biochem. Biophys. 423, 12-22 (2004)... 

In this introductory review we have presented the most relevant 3-D structural characteristics of a selected set of peptidomimetics that, hopefully, will he of help to the nonspeciahzed scientists for potential use in the currently exploding field of chemical biology. More specifically, we have discussed examples of peptide surrogates with main-chain and side-chain modifications either at the a-nitrogen or at the a-carhon, or at both a-and fS-carbons, or with different types of cychzations (N-o-N, N-o-C , and C -o-C ). For journal issues or books devoted to these and other types of peptidomimetics, the reader is referred to References 67-73. 

Richardson, D.J. and Watmough, N.J. (1999) Inorganic nitrogen metabohsm in bacteria. Current Opinion in Chemical Biology, 3, 207-219. 

Azido compounds are versatile molecules. They are used extensively in both organic reactions and chemical biology. All azides are potentially explosive and must be handled with care. Azides, which have been known for over 100 years, are the most widely used precursors of nitrenes. like diazo compounds, they possess a linear 1,3-dipolar stracture and are easily prepared, often by introduction of the azide (Nj ) ion from inorganic salts such as sodium azide. The thermal stability of azides is critically dependent on the substituent on nitrogen. Most azides decompose thermally in the range 100-200 °C to give nitrenes. Azides are also readily decomposed photochemically, and this is often the method of choice, particularly for mechanistic studies. Like diazo compounds, the decomposition of... 

Azides are very versatile and valuable synthetic intermediates, known for their wide variety of applications, and have been employed for the synthesis of a number of important heterocyclic compounds. Azides also represent a prominent class of 1,3-dipoles, and their cycloaddition to multiple tt-bonds is an old and widely used reaction (1988CR297). The dipolar cycloaddition of an azide to an alkene furnishes a triazoline derivative (2003MI623). Azide-alkene cycloadducts can extrude nitrogen at elevated temperatures to form aziridines or imines, depending upon the substrate and reaction conditions. The cycloaddition of azides with alkynes affords triazolidine derivatives which have been a focus in the area of chemical biology and have received much recent attention (2008AGE2596, 2008CR2952). In this section of our review, we recount some developments of the 1,3-dipolar cycloaddition reaction of azides that have been used for the synthesis of various alkaloids. 

Bioinorganic Chemistry Carbon Cycle Climatology Greenhouse Eeeect and Climate Data Nitrogen Cycle, Biological Ozone Measurements AND Trends Planetary Atmospheres Transport and Fate oe Chemicals in the Environment Tropospheric Chemistry... 

In Olomouc at the department of analytical chemistry of the Palacky University, the electrochemical problem of penetration of chemicals into ecosystem in the case of reduction mechanism and determination of nitrogen-containing biologically active compounds was studied [146]. 

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