12-07564. Picrolichenic Acid [Archived]
Nomenclature
CAS number: 466-34-2
6-Hydroxy-2′-methoxy-2,4′-dioxo-4,6′-dipentylspiro[benzofuran-3(2H),1′-[2,5]cyclohexadiene]-5-carboxylic acid; picrolichenin. C25H30O7; mol wt 442.50.
C 67.86%, H 6.83%, O 25.31%.
Description and references
Bitter acidic principle of crustose lichen, Pertusaria amara (Ach.) Nyl., Pertusariaceae. Isoln: Alms, Ann. Pharm. 1, 61 (1832). Identity of picrolichenin and picrolichenic acid: Zopf, Ann. 321, 38 (1902). Isoln and structure: Wachmeister, Acta Chem. Scand. 12, 147 (1958). Synthesis: Davidson, Scott, J. Chem. Soc. 1961, 4075.
Properties
Prisms from benzene, dec 184-187°; prisms from aqueous acetic acid, decomp 187-190°. Intense bitter taste similar to that of quinine. Optically inactive. uv max: 245, 270-277 nm (ε 24,000, 7800). Readily sol in most organic solvents except benzene and light petroleum.Derivative
Methyl picrolichenate.C26H32O7; mol wt 456.53.
C 68.40%, H 7.07%, O 24.53%.
Properties
Needles from methanol, mp 102-103.5°. Soluble in cold 0.5N NaOH.Derivative
Methyl O-methylpicrolichenate.C27H34O7; mol wt 470.55.
C 68.92%, H 7.28%, O 23.80%.
Properties
Needles from hexane, mp 80-82°. Practically insol in cold 0.1N NaOH.Status
This monograph has been retired and is no longer subject to revision or update.