From the mycelium of the following fungi grown on a synthetical medium a triterpene acid, C,,H,,O,, eburicoic acid, has been isolated-Polyporus anthracophilus Cooke, P. eucalyptorurn Fr., P. sulphureus (Bull) Fr., F o m s oficinalis Fr., and Lentinus Hactyloides Clel. The acid from the last two mentioned sources was accompanied by a compound of the same type, containing a conjugate system of double bonds, whilst from mycelium of P. anthracophilus Cooke grown naturally on Eucalyptus regnans wood the acetyl derivative of eburicoic acid was isolated.Eburicoic acid is a triterpenoid hydroxy-acid having a tertiary carboxyl group and two double bonds, of which one is easily hydrogenated and is present in a methylene group since on ozonolysis O-acetyleburicoic acid gives formaldehyde. In confirmation of this, scission of the diol formed from methyl O-acetyleburicoate gave rise to a compound believed to be a ketone along with formaldehyde. Eburicoic acid was converted into the hydrocarbon eburicene-1 by a series of standard reactions. Similarly, it appears that the hydroxyl group is located in a terminal ring system and is in the a-position to the carbon atom carrying the gem-dimethyl group. It is concluded that eburicoic acid probably belongs to the tetracyclic series of triterpenes.IN the course of studies at present in progress in these laboratories on the metabolic products of a considerable number of the higher fungi, mainly of the class Basidiomycetes, grown on a synthetical medium, a sample of Eucalyptus regnans wood rotted by the fungus Polyporus anthvacophilus Cooke was examined. From the mass of mycelial hypha: encompassing the decayed wood the acetyl derivative of a monobasic acid, m. p. 292", was isolated (cf. Gascoigne et al., Nature 1950, 166, 652; 1951, 167, 570) which, from its properties and composition, appeared to belong to the triterpene class. When the fungus responsible for the rot was isolated and grown on a synthetical medium the mycelium contained only the parent acid and not the expected acetate. A preliminary investigation of the acid and some of its derivatives (loc. cit.) indicated that the compound had the empirical formula C,,H&, but, from a subsequent more detailed examination of the Fompound together with its derivatives and degradation products described in the present communication, it became clear that the acid had the formula C,,H4,0,. From an examination of the literature it appeared that since the methyl esters and their acetates had similar melting points this acid might be identical with an acid, C3$-&@3, m. p. 283", obtained by Kariyone and Kurono ( J . Pharm. Soc. Japan, 1940, 60, 110, 318) from the naturally grown fungus Fornes oficinalis Fr., which these authors had named eburicoic acid. Accordingly the fungus Fomes oficinalis Fr. was cultivated on the standard medium and from the mycelium an acid was isolated which differed from the product Kariyone and Kurono's acid.Acid from P. anthracophilus Cooke. M. p.
