A neutral principle, in its commercial, more or less impure form, extracted from Goa or Araroba Powder, a substance found deposited in the wood of Andira Araroba Aguiar (nat. ord. Leguminosae).

Habitat

Brazil.

Characters

A pale, orange-yellow, microcrystalline powder, odorless and tasteless; turning brownish-yellow on exposure to air.

Solubility

Very slightly soluble in cold water or Alcohol; soluble in 33 parts of boiling Benzol, in Chloroform, and in solutions of the alkalies.

Composition

The chief constituent of Goa powder is Chrysarobin, C27H30O14. Synonyms. - Rhein. Chrysophan (see p. 490). In the fresh plant it probably exists as a Glucoside, but this is slowly oxidized into Chryso-phanic Acid, C15H10O4, and glucose.

Preparation

Unguentum Chrysarobini. Chrysarobin Ointment

Chrysarobin, 5; Benzoinated Lard, 95.

Action Of Chrysarobin

External

It is a powerful irritant to the skin, which it stains yellowish brown. Linen is stained the same color. (The stain may be removed by a weak solution of caustic soda or chlorinated lime.) It is antiparasitic.

Internal

It is cathartic and very irritating to the stomach and bowels, causing vomiting and purging. It is excreted by the kidneys, and stains the urine yellow.

Therapeutics Of Chrysarobin

It is used as an antiparasitic in ringworm, and to excite healthy inflammation in chronic cutaneous diseases, especially psoriasis and acne rosacea. A pigment (chrysarobin, 1; solution of gutta percha, 9 solution of gutta percha is made by decantation of gutta percha, 1; lead carbonate, 1; chloroform, 9;) is more cleanly than the ointment and does not stain the clothes. Chrysarobin has also been given internally for skin diseases, but as it is so irritating this practice is not advisable.