4942. Indican (Plant Indican)

Nomenclature

CAS number: 487-60-5
1H-Indol-3-yl-β-d-glucopyranoside; 3-(β-glucosido)indole; indoxyl-β-d-glucoside.
C14H17NO6; mol wt 295.29.
C 56.94%, H 5.80%, N 4.74%, O 32.51%.

Description and references

Isolated from Indigofera spp., Leguminosae and from Polygonum tinctorium Ait., Polygonaceae. Extraction procedure for the glucoside: Hoogewerff, Meulen, Rec. Trav. Chim. 19, 166 (1900); Perkin, Bloxam, J. Chem. Soc. 91, 1715 (1907); Perkin, Thomas, ibid. 95, 793 (1909). About 3% indican is found in 4-day old air-dried leaves of Indigofera tinctoria. Synthesis: Robertson, J. Chem. Soc. 1927, 1937; Robertson, Waters, ibid. 1933, 30; Freudenberg et al., Ber. 85, 641 (1952).

Chemical structure

Derivative

Trihydrate.

Properties

Orthorhombic spear-shaped needles, mp 57-58°. [α]19546 66°. After heating in vacuo (oil pump) over H2SO4 for 48 hrs the hemihydrate is obtained, mp 101°. Robertson obtained the anhydrous compound by heating in the steam oven for 3 hrs, at 110° for 1 hr, and at 160° for 5 minutes. Perkin and Bloxam obtained anhydr indican by treating the trihydrate with boiling alcohol and boiling benzene. Anhydr indican decomposes at 178-180°. [α]D15 66° (c = 2); [α]19546 78° (c = 0.6). Sol in water, methanol, alcohol, acetone; slightly sol in ether, benzene, chloroform, ethyl acetate, carbon disulfide. Anhydr indican is sparingly sol in anhydr alcohol.