Reactions with amino acids

Nicotine, structure of, 30, 916 Ninhydrin, reaction with amino acids, 1030... 

Ninhydrin Reaction with Amino Acids, Biochemistry Survey Lecture. D. S. Moore, Department of Chemistry, Howard University,... 

Scheelite, 25 349-350 Scheelite sorting, 16 626 Scheibel column, 10 777-778 Scheibler filter, 11 364 Schiff base(s), 21 203, 204, 25 100-101 chelating agents, 5 712t reaction with amino acids, 2 567 reaction with aniline, 2 786 thermochromic materials, 6 622-623 Schiff base chemistry, 24 42 Schiff base (reductive amination) method, for covalent ligand immobilization, 6 396t... 

Y. Kurono, T. Furukawa, T. Tsuji, K. Ikeda, Esterase-Like Activity of Human Serum Albumin. VI. Reaction with p-Nitrophenyl Glycinate , Chem. Pharm. Bull. 1988, 36, 4068-4074 Y. Kurono, I. Kushida, H. Tanaka, K. Ikeda, Esterase-Like Activity of Human Serum Albumin. VIII. Reaction with Amino Acid p-Nitrophenyl Esters , Chem. Pharm. Bull. 1992, 40, 2169-2172. 

Y. Kurono, I. Kushida, H. Tanaka, K. Ikeda, Esterase-Like Activity of Human Serum Albumin. VIII. Reaction with Amino Acid p-Nitrophenyl Esters , Chem. Pharm. Bull. 1992, 40, 2169-2172. 

Fluoranthene, >3, 103, 293 Fluorescamine, reaction with amino acids. JHO... 

Further methods [205] successfully employed to synthesize fuUeropyrroUdines include acid-catalyzed [213] or thermal [214] desilylation of trimethylsilyl amino derivatives, tautomerization of a-aminoesters of immonium salts [215] and imines [216, 217], reaction with aldehydes in the presence of aqueous ammonia [218], reaction with oxazolidinone [204] or photochemical reaction with some amino derivatives [219-223], The reaction with amino acids and aldehydes was also carried... 

In order to improve this reaction, a proper understanding of all parameters affecting product yield is desired. Clearly, the high enzyme consumption is a major obstacle for an efficient and economically feasible process. A likely cause of the inefficient use of DERA in this conversion is enzyme deactivation resulting from a reaction of the substrates and (by-) products with the enzyme. In general, aldehydes and (z-halo carbonyls tend to denature enzymes because of irreversible reactions with amino acid residues, especially lysine residues. From the three-dimensional structure it is known that DERA contains several solvent-accessible lysine residues [25]. Moreover, the complicated reaction profile as shown in Scheme 6.5 indicates the potential pitfalls of this reaction. 

Dansylation is often used for the determination of free and N-terminal amino acids. Dansyl chloride (5-dimethylaminonaphthalene-l-sulfonyl chloride, DNS-C1) reacts with the amino substituent of amino acids to form highly fluorescent derivatives [75,76]. The method is particularly useful for the analysis of trace components due to the high sensitivity of the products. The derivatives are usually separated by TLC on various types of layers. Separations of DNS-amino acids by flat-bed techniques have been reviewed [77]. Separations by column chromatography have been examined on polyamide [78] and Amberlite IRC-SO [79]. Although many variations of the dansylation reaction with amino acids have been reported, the one described below [77] appears to be the most common. 

Thiol esters. DPPA in combination with triethylamine promotes coupling of carboxylic acids and thiols to form thiol esters, R COSR2 (50 95% yield). Only slight racemization occurs during reaction with amino acids.2... 

Amino acids (isoleucine, phenylalanine, arginine and alanine) have been analysed on a microchip with a post-channel reaction with amino acid oxidase reaction [144], Pre-channel derivatisation of amino acids with naphthalene-2,3-dicarboxyaldehyde (NDA) has been described for facilitating its amperometric detection [145]. Separation and direct detection of amino acids without derivatisation have also been achieved in microchips [89,109,122,132,146-148]. 

The addition-compounds of sodium bisulfite (or potassium bisulfite) with numerous sugars have199a been prepared in a pure state and have been shown to react with aromatic amines under conditions similar to those under which the free sugars react. -Substituted glycosylamines are formed, but the reaction with amino acids was not reported. 

Conversion of the isolated A-TBDMS carboxylic acid 111 to the active ester and reaction with amino acid esters yielded after desilylation the /3-sultam peptides 112 and 113. Removal of the protecting groups was also possible with benzylic esters but attempted hydrolysis of alkyl ester groups resulted in hydrolysis of the /3-sultam ring. Catalytic hydrogenation of the benzyl esters afforded the N-silylated /3-sultam peptides 114 in quantitative yields (Scheme 34) <2004M979>. 

Thermal aromas result from the Maillard reaction. By heating carbohydrates with amino acids degradation is accelerated yielding reactive compounds which, by new reactions with amino acids, are converted to heterocyclic products. Results of model investigations of glucose or its degradation compounds with the amino acids serine and phenylalanine are discussed. 

Upon reaction with amino acids, in the Strecker degradation, unstable imines are formed, which may easily decarboxylate, leaving an enamine, which upon hydrolysis yields an aldehyde from the amino acid and an a-aminoketone from the di-carbonyl-compound. 

When oxides of nitrogen come in contact with water, both nitrous and nitric acids are formed (18) (Table IV). Toxic reactions may result from pH decrease. Other toxic reactions may be a consequence of deamination reactions with amino acids and nucleic acid bases. Another consideration is the reactions of oxides of nitrogen with double bonds (Table IV). The cis-trans isomerization of oleic acid exposed to nitrous acid has been reported (19). Furthermore, the reaction of nitrogen dioxide with unsaturated compounds has resulted in the formation of both transient and stable free radical products (20, 21) (Table V). A further possibility has been raised in that nitrite can react with secondary amines to form nitrosamines which have carcinogenic properties (22). Thus, the possible modes of toxicity for oxides of nitrogen are numerous and are not exhausted by this short list. 

Asymmetric cycloaddition reactions with amino acid esters as chiral auxiliaries 91G227. 

The postcolumn methods usually provide detectivity and are run online. The classic example, which has been mentioned several times, is the ninhydrin reaction with amino acids. For best results, the reaction must be fast and the mixing chamber efficient without introducing excessive dead volume. Most of the examples are in LC. 

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