Ninhydrin 2,2-dihydroxyindane

Ninhydrin (2,2-dihydroxyindane-13-dione) reacts with primary and secondary amino compounds to form characteristic colored compoimds. Since its discovery by Ruhemann in 1910 [1], this colorimetric reaction has been widely used for the detection of amino acids, peptides, proteins, and amines. By the reaction with primary amino acids, a typical... 

Another experimental result is also consistent with the hypothesis that cyclic 1,2,3-triketones are not stable. 2-Diazoindan-l,3-dione (9.91) is oxidized by eA butyl hypochlorite in ethanol to the 2-monoacetal 9.92 of indan-l,2,3-trione. The monoacetal undergoes hydrolysis to 2,2-dihydroxyindan-l,3-dione (ninhydrin hydrate 9.93), but the trione itself could not be identified (9-41). 

To determine the presence of ephedrine and its derivatives using TLC, a solutimi of butanol, glacial acetic acid, and water (4 1 1) as the mobile phase andninhydrin (2,2-Dihydroxyindane-l,3-dione) for localizations has typically been used [28,29, 34]. O Dowd and colleagues reported that ethanol extract of in vivo or in vitro grown plants often contains compounds that show a positive test for ephedrine and pseudoephedrine with ninhydrin in TLC, but such compounds were absent in HPLC analysis. Therefore, TLC cannot be used as a sufficient and reliable method and, in parallel, a more confirmative method must be conducted [28],... 

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