Matsuda, Kazuhiro published the artcileIndican as a feeding stimulant to the strawberry leaf beetle, Galerucella vittaticollis Baly attacking polygonaceous plants, Computed Properties of 2642-37-7, the publication is Applied Entomology and Zoology (1983), 18(4), 552-4, database is CAplus.
Feeding by G. vittaticollis was stimulated by indicans and K 3-indoxylsulfate at 0.001-0.1M, but not by indoxyl acetate, IAA, indigo, indole, or isatin. Indican was detected in Polygonum tinctorium leaves but not in leaves of other polygonaceous plants or strawberry leaves. Other beetles which feed on polygonaceous plant were not stimulated to feed by indican or related compounds
Applied Entomology and Zoology 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 C8H6KNO4S, Computed Properties of 2642-37-7.
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