1,2-Naphthoquinone 4 sulfonate

Naphthoquinone-4-sulfonic Acid- Perchloric Acid - Formaldehyde Reagent... 

Naphthoquinone-4-sulfonic Acid-Perchloric Acid-Formaldehyde Reagent 353... 

Primary amines and substances with reactive methylene groups react with 1,2-naphthoquinone-4-sulfonate to yield intensely colored p-quinoid derivatives, which, in the case of aryl amines, are indophenol dyes [12, 13]. 

Al-Ghannam et al. [25] described a simple fluorimetric procedure for determination of three pharmaceutical compounds containing thiol groups, including penicillamine. In this method, the drugs are treated with 1,2-naphthoquinone-4-sulfonic acid. The later compound is reduced to l,2-dihydroxynaphthalene-4-sulfonic acid, which is measured fluorimetrically (excitation = 318 nm, emission = 480 nm). The method is sensitive to 0.5 1.5 pg/mL, with a detection limit of 0.05 pg/mL (S/N = 2). 

C10H8N2O5S 1,2-Naphthoquinone-4-sulfonic acid dioxime Ebchaction-photometric Co, Cu, Fe, Ni 3... 

Salts of 1,2-naphthoquinone-4-sulfonate have been prepared by the oxidation of 2-amino-i-naphthol-4-sulfonic acid with nitric acid,2 or by the oxidation of the more readily available i-amino-2-naphthol-4-sulfonic acid with the same reagent.3,4 5... 

Naphthoquinone-4-sulfonic acid, sodium salt (0.5% in 1 Nacetic acid) Ninhydrin... 

Naphthoquinone-4-sulfonic acid/perchloric acid Pink spots that change to blue upon prolonged heating (cholesterol limit 0.03y) 65,101... 

Cytochrome 62 is stereospecific for l(- -)-lactate. It also oxidizes other a-hydroxymonocarboxylic acids at slow rates 80, 96). As electron acceptors ferricyanide, methylene blue, 2,6-dichloroindophenol, 1,2-naphthoquinone 4-sulfonate, and cytochrome c have been used. This wide acceptor specificity is characteristic of a number of flavoproteins, which are generally capable of reducing quinoid structures and ferric compounds 97). However, as will be seen below, cytochrome c is considered to be the physiological electron acceptor for the yeast L-lactate dehydrogenase. 

Preparation. One method utilizes ammonium 1,2-naphthoquinone-4-sulfonate. One liter of methanol is cooled to 0° in a salt-ice bath during slow addition of 80 ml. of coned, sulfuric acid. The cooling bath is removed, 1 mole of the ammonium salt is added and stirred to an even paste, and the temperature is gradually raised to boiling, with separation of the ether (2), more methanol is added, and the mixture is o o O... 

White or gray needles, usually Contg 0.5 11.O May turn pink on exposure to light, especially when moist. Insol in water, alcohol, ether, benzene sol in hot sodium bisulfite soln sol in alkaline soln but such solns oxidize quickly on exposure to air yielding a brown substance which is sol in hot water giving a green soln. Controlled oxidation with HNOj yields ammonium 1,2-naphthoquinone-4-sulfonate, see Fieser, toe. eiz... 

Sodium 0 -Naphthoquinone-4 -sulfonate. 3,4-Di-hydro 3,4 dioxo-l-naphthalenesulfonic acid sodium salt sodium l,2-naphthoquinone 4 sulfonate 1,2-naphthoquinone-4-sulfonic acid sodium salt d-naphthoquinone-4-sul-tonic acid sodium salt. C,flH5NaOjS mol wt 260.20. C 46.16%, H 1,94%, Na 8.84%, O 30.74%, S 12.32%. Prepn Folin, J. Biol. Chem. 51, 377 (1922). 

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