12-02066. Cetraric Acid [Archived]

Nomenclature

CAS number: 489-49-6
9-(Ethoxymethyl)-4-formyl-3,8-dihydroxy-1,6-dimethyl-11-oxo-11H-dibenzo[b,e][1,4]dioxepin-7-carboxylic acid; cetrarin.
C20H18O9; mol wt 402.35.
C 59.70%, H 4.51%, O 35.79%.

Description and references

From Iceland moss, Cetraria islandica (L.) Ach., Parmeliaceae. Isoln: Schnedermann, Knopp, Ann. 55, 144 (1845). Structure: Asahina, Asano, Ber. 66, 893 (1933).

Chemical structure

Properties

Very bitter prisms from alcohol or acetic acid. Bitterness threshold 1:50,000. Practically insol in hot water, petr ether, benzene, ether, or in cold methanol, alc, acetone and acetic acid. Sol in aq solns of alkalies or their carbonates forming a yellow soln that turns brown on standing.

Status

This monograph has been retired and is no longer subject to revision or update.