Barbaloin

Aloin; 1,8-Dihydroxy-3-hydroxymethyl-10-(β-d-glucopyranosyl)anthrone; C₂₁H₂₂O₉,H₂O = 436.4 (1415-73-2)

Yellow to dark-yellow, crystalline powder, or yellow needles, darkening on exposure to air and light, sparingly soluble in water and in ethanol (96%), soluble in acetone, in ammonia and in solutions of alkali hydroxides.

A(1%, 1 cm) about 192 at 269 nm, about 226 at 296.5 nm, about 259 at 354 nm, determined on a solution in methanol and calculated with reference to the anhydrous substance.

Complies with the following test.

Homogeneity Carry out the test for Other species of Rhamnus, anthrones described under Frangula bark applying to the plate a solution containing only the reagent being examined. The chromatogram obtained shows only one principal spot.