Origin. The American arbor vitae or Washington cedar is known botanically by a number of synonyms: Thuja plicata, Lamb, non Don, Th. gigantea, Nutt., Th. Menziesii, Dough, 777. Doug/asii, Nutt. and 777. Lobii hort. or more correctly Th. Lobbi hort., after Lobb, who in 1853 introduced the tree into Europe from western America.
1) Liebig's Annalen 275 (1893), 182.
2) Wallach, Liebig's Annalen 279 (1894), 384.
3) Berl. Berichte 27 (1894), 895.
4) Liebig's Annalen 353 (1907), 213.
5) Report of Schimmel & Co. April 1892, 57.
Properties and Composition. From the air dried leaves of the Pacific arbor vitae, also known as red cedar or canoe cedar along the Pacific coast of North America, W. C. Blasdale1) obtained 2,8 p. c. of a volatile oil of terpene-like odor and the following constants: d15o 0,8997; aD + l°45'; nD 1,4575; b. p. 150 to 225°. Besides thujone, which was isolated from fraction 198 to 200° (d15o 0,9142; aD - 0°52'; nD 1,4532) and characterised in the usual manner, no other constituents of the oil could be identified.
According to J. C. Frye, the material distilled by I. W. Brandel and A. H.Dewey2) was obtained from Thuja plicata = Th. gigantea = Th. Menziesii. Upon distillation with water vapor the leaves and twigs yielded 0,8 to 1,4 p. c. of a light yellow oil, with a slightly pungent camphor-like odor. d25o 0,9305; aD25o - 6,9°; A. V. 0,518; S. V. 5,7; E. V. after acetylation 6,2; soluble in all proportions in 70 p. c. alcohol. More than 75 p. c. of the oil distilled between 190 and 203°. It is remarkable that each and every fraction of the oil, which was laevogyrate originally, after fractionation was dextrogyrate. Terpenes were present to the extent of about 3 p. c. Of these a-pinene was identified by its nitrosochloride melting at 103°. The presence of cymene was not definitely established since fraction 175 to 180° upon oxidation yielded only a small amount of an acid melting at 121°. Thujone was found principally in fraction 200 to 203°. It was characterized by its tribromide and by the boiling point of the ketone (203°) regenerated from the acid sulphite addition product. After the thujone had been removed, the presence of fenchone in the principal fraction, mainly 190 to 197,5°, was established by its oxime melting at 164°. The residue remaining above 220° revealed a high saponification value and doubtless contained borneol ester since, upon oxidation with nitric acid, camphor was obtained. After reduction with sodium and alcohol, the oil yielded upon acetylation an ester value of 96,83 p. c. corresponding to about 28,5 p. c. of alcohols.
1) Journ. Americ. chem. Soc. 29 (1907), 539. 2) Pharm. Review 26 (1908), 248.
The leaves distilled by Schimmel & Co.1) were sent by Prof. Heckel of Marseilles and labled Thuja Lobii.
About 1,32 p. c. of an oil of a light yellow color and a strong thujone odor were obtained. Like the oil discribed by Blasdale, it was dextrogyrate: d16o 0,9056; aD + 5°4'; nD20o 1,45721; A.V. 0,8; E. V. 16,9; soluble in 70 p. c. alcohol (about 1:8) but always with opalescence; with 1,2 vol. and more of 80 p. c. alcohol it, however, forms a clear solution. The thujone, isolated by means of the semicarbazone, revealed itself as /-a-thujone. After twofold recrystallization from alcohol, the semicarbazone melted at 185 to 186°. The optical rotation of the thujone regenerated therefrom with phthalic acid anhydride amounted to aD - 5° 12'.
Finally, R. E. Rose and C. Livingston2) have distilled an oil from the leaves and twigs with a yield of 1 p. c. which possessed the following properties: d20o 0,913; [a]D20o - 4,77°; nD20o 1,4552; A. V. 0,518; E. V. 2,28; E. V. after acetylation 8,8. It was soluble in 70 p. c. alcohol in all proportions. 85 p. c. of the oil boiled between 100 and 110° (40 mm.) and consisted of a-thujone (m. p. of the tribromide 121 to 122°; of the semicarbazone 186 to 188°). In addition the oil contained 3 to 5 p. c. of d-a-pmene, which was identified by means of its physical constants and its nitroso-chloride. These investigators also found 1 to 3 p. c. of d-tanacetyI alcohol which was characterized by its physical constants: b. p. 210 to 220°; d25o 0,9266; [a]D25o + 29,8°; nD26o1,46207. It appears to exist in the oil as acetate. Fenchone was not found.
Upon distillation of the shavings of the wood with water vapor and shaking out of the aqueous distillate with ether, Blasdale3) obtained white crystals which melted at 80°, which had the characteristic pungent odor of the wood, and which possibly have the formula C10 H12 O2.
1) Report of Schimmel & Co. April 1909, 89. 2) Journ. Americ. chem. Soc. 34 (1912), 201. 3) Loc. cit