The Strecker degradation reaction was evaluated as a means of modifying hemoglobin in vitro, utilizing ninhydrin as a model compound. Ninhydrin led to modification of hemoglobin (when incubated with hemoglobin or red cells) at physiologic temperature and pH. Isoelectric focusing documented the formation of new hemoglobin bands, all with decreased (more negative) isoelectric points that hemoglob...

The products of the reaction of ninhydrin with a-amino acids are, in general, the corresponding aldehyde of one less carbon atom than the original compound, COZ, and, at pH 5 to 7, an intensely colored compound (thought to be the anion of diketohydrindylidene-diketohydrindamine), which contains nitrogen from the amino acid. If the pH is kept at 2.5 or lower, this colored compound is not produce...

A simple spectrophotometric method for determination of glucosamine release from sustained release (SR) hydrophilic matrix tablet based on reaction with ninhydrin is developed, optimized and validated. The purple color (Ruhemann purple) resulted from the reaction was stabilized and measured at 570 nm. The method optimization was essential as many procedural parameters influenced the accuracy of...

It is shown that o-carboxyphenylglyoxal, which is converted from ninhydrin by alkali, produces a chemiluminescent lucigenin reaction under alkaline conditions when with reacted with guanidino compounds. It is also demonstrated that phenylglyoxal, which is a model compound of o-carboxyphenylglyoxal, produces a strong chemiluminescent lucigenin reaction under alkaline conditions when reacted with...

In the present method the CO2 evolved by decarboxylating amino acids with ninhydrin is transferred to standard barium hydroxide and titrated. The conditions for making the ninhydrin reaction quantitative are those previously worked out for applicat,ion in the manometric method (6, 7). The transfer of the CO, to the barium hydroxide is done by a distillation in vacua which is completed in 2 to 3...

The characteristic red color produced when proline interacts with ninhydrin in acidic solutions has recently been proposed for use in the quantitative assay of this imino acid (1,Z). These methods could not, however, be applied directly to the estimation of proline in biological fluids, since other amino acids interfere to some extent and must be removed either by chromatography (1) or by destr...

Kinetic studies of the title reaction have been carried out in the absence and the presence of organic solvents ( 1propanol, dimethylsulFoxide, acetonitrile and methy l cellosolve) as a function of pH, te mperature and [reactant] in sodium ace tate-aceti c acid buffer. Addition of each organic solvent increases the absorbance as well as the rate constant of the RlIhell/allil 's purple formation...