Indoxyl sulphate

B27. Bowmer, C. J., and Lindup, W. E., Decreased drug binding in uremia Effect of indoxyl sulphate and other endogenous substances on the binding of drugs and dyes to human albumin. Biochem. Pharmacol. 31, 319-323 (1982). 

Trimethylamine N-oxide 1 -Methylnicotinamide Allantoin Urocanic add Indoxyl sulphate... 

Chromatography revealed excretion of a number of amino acids in his urine, with abnormally high concentrations of tryptophan, phenylalanine, tyrosine, leucine, isoleucine and valine. His urine also contained relatively high concentrations of a number of indolic compounds, including indoxyl sulphate (indican), indolyllactate, indolylacetate, indolylacetamide and indolylacetylglutamine, which are not detectable in the urine of normal subjects. 

Three stages are recognisable in this curious test (i.) hydrolysis of indoxyl sulphate and liberation of free indoxyl by the action of the acid (ii.) union between two molecules of indoxyl to form the leuco-base, or precursor of indigo blue (iii.) oxidation of the leuco-base to form the pigment. If the oxidiser be in excess a fourth stage terminates the reaction, namely, (iv.) oxidation of the indigo blue to the almost colourless isatin. 

Organic Sulphates.—Esters of phenols, cresols, indoxyl, and other alcohols. They appear as detoxication products in mammalian urine. Taurine occurs in bile acid. 

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