The Chemistry of Ninhydrin.

Spectrophotometric Determination of Alzheimer’s Drug, Memantine Hydrochloride in Biological Samples Using Ninhydrin and Ferric Chloride

“…The use of the ninhydrin for the detection and quantitative estimation of amino acids and imino acids depends on the formation of Ruhemann's purple [36]. The primary amino group of MEM reacted with 2-hydroxyindan-1,3-dione in alkaline medium to form the amino compound which condensed with ninhydrin to give diketohydrindylidene-diketohydrindamine (Scheme 3), which interacts with amino group of the drug resulting in the formation of a blue colored product (Ruhemann's purple) which absorbed maximally at 595 nm.…”

Development and application of spectrophotometric method for the determination of cefaclor in pharmaceutical formulations

“…17 This compound would further react with amino group of cefaclor to give the product, which absorb maximally at 560 nm as shown in Figure1. The optimum conditions for determination of cefaclor were established.…”

SYNTHESIS AND CHARACTERIZATION OF SOME METAL COMPLEXES OF A SCHIFF BASE DERIVED FROM NINHYDRIN AND α ,L-ALANINE

“…The chemistry of the reaction of ninhydrin with amino acids has been extensively studied by several workers [6,20,21]. The mechanism, however, was not well understood until very recently and this gave rise for a series of theories as reviewed by McCaldin [20].…”

“…The mechanism, however, was not well understood until very recently and this gave rise for a series of theories as reviewed by McCaldin [20]. A simplified form of the mechanism proposed by Filippovich and McCaldin is shown in Scheme 1 [20][21][22].…”

“…The mechanism, however, was not well understood until very recently and this gave rise for a series of theories as reviewed by McCaldin [20]. A simplified form of the mechanism proposed by Filippovich and McCaldin is shown in Scheme 1 [20][21][22]. It has a condensation step that leads to a Schiff base formation followed by decarboxylation, hydrolysis and finally further condensation with another ninhydrin molecule to give the final product, Ruhemann's purple [20][21][22].…”