Wellers, Georges published the artcileExchange between S35 of ammonium sulfate and S32 of indoxylsulfate in aqueous solution, Formula: C8H6KNO4S, the publication is Compt. rend. (1960), 1140-2, database is CAplus.
A solution of indoxylsulfate, isolated from the urine of rabbits fed indole and methionine, was added to a solution of (NH4)2S35O4, and after 48 hrs. the mixture was chromatographed for 15 hrs. The radioactivity on the paper was determined before and after spraying with Ehrlich’s reagent. The radioactivity appeared only in the indoxylsulfate spot. The authors believed that the transfer of radioactivity takes place between the sulfate ions rather than between the S atoms. Although direct esterification of phenols by mineral sulfates would explain the appearance of radioactivity in the conjugated sulfates of the urine of animals administered Na2S35O4, the fact that exchange between (NH4)2SO4 and indoxylsulfate does occur would indicate that the former may not be the full explanation.
Compt. rend. published new progress about 2642-37-7. 2642-37-7 belongs to indole-building-block, auxiliary class Indole,Salt,Sulfonate,Inhibitor,Inhibitor, name is Potassium 1H-indol-3-yl sulfate, and the molecular formula is C6H10O7, Formula: C8H6KNO4S.
Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles