J. Waite, M. Tanzer
Feb 1, 1981
Citations
2
Influential Citations
61
Citations
Quality indicators
Journal
Analytical biochemistry
Abstract
Abstract The catecholic moiety of simple and monosubstituted o-diphenols reacts with nitrite to produce a bright red (λmax 500 nm) chromophore in alkali. Most of these o-diphenols have extinction coefficients in the range of 7000 to 10,000 cm−1 m −1 at 500 nm. Di- and tetrasubstituted o-diphenols, monophenols, and m- and p-diphenols in the concentration range 4 to 20 μg/ml do not form visible reaction products with nitrite. Monomethyl catechol ethers and 2,3-dihydroxypyridine react with nitrite forming yellow to orange products in alkali. The nitrite-sensitive o-diphenols tested included pyrocatechol, 4-methylcatechol, 2,3-dihydroxybenzaldehyde, protocatechuic acid, 4-nitrocatechol, 4-tert.-butylcatechol, 3,4-dihydroxyphenylacetic acid, 3,4-dihydroxyphenylpropionic acid, l -epinephrine, dopamine, l -3,4-dihydroxyphenylalanine (DOPA), (+)-catechin, poly(DOPA-Glu-DOPA), poly(Glu-DOPA), poly(Glu-Glu-Glu-DOPA), and the protein periostracin. We also found that detection of DOPA proteins on polyacrylamide gels is readily accomplished by reaction with nitrite.