Oleum Cinnamomi zeylanici. - Ceylon-Zimtdl. - Essence de Cannelle de Ceylan.
Origin and Production. The genus Cinnamomum of the family Lauraceae consists of evergreen, aromatic trees and shrubs. Several of the species yield volatile oils that are much used. Both the underground as well as the overground portions of the Ceylon cinnamon shrub Cinnamomum zeylanicum, Nees, contain volatile oil. Whereas in the case of the cassia shrub, Cinnamomum Cassia, Blume, the oils obtained from the different parts of the plant are almost identical, in the case of the Ceylon cinnamon shrub the oil from the bark is very different from that of the leaves also from that of the roots.
Cinnamomum zeylanicum is a tree indigenous to the forests of Ceylon. Formerly the bark was collected from the trees that grew wild. At present it is collected principally from the cultivated plants which are grown shrub-like in the cinnamon gardens1).
For the distillation of the oil the shavings and fragments which result in the peeling and which since 1867 have been exported as "chips" are used. The distillation of the oil from chips was introduced into Germany by Schimmel & Co., in 1872. The yield of oil from the chips amounts to between 0,5 and 1,0 p. c. It should be noted, however, that both yield and properties of the oil depend largely on the method of distillation5).
The oil distilled in Ceylon is rarely the pure distillate of the bark. As a rule it contains much leaf oil. Either the leaves are distilled with the bark or the cheaper and inferior leaf oil is added to the bark oil.
In recent years much cinnamon bark, likewise from Cinna-momum zeylanicum, Nees, is obtained in the Seychelles. It however, enters the market in thick pieces and represents the bark of the wild trees1). On the average a tree yields 20 lbs. of bark. Especially large trees yield as much as 100 lbs.
1) The cultivation, production and packing of Ceylon cinnamon is described in detail by A. Tschirch in his Indische Heil- und Nutzpflanzen. Berlin 1892, p. 86. - Comp. also: Der Pflanzer 8 (1912), 611.
2) Comp. Report of Schimmel & Co. April 1909, 32; October 1910, 34.
In the Seychelles the bark oil is likewise distilled2). However, compared with the pure Ceylon cinnamon oil (i.e. the oil distilled without leaves) it has a less pleasant odor, hence must be pronounced as inferior. (See below under Properties and Composition.)
Properties. Ceylon cinnamon oil is a light yellow liquid possessing the agreeable, delicate odor of Ceylon cinnamon and a spicy, sweet and burning taste.
d15O1,023 to 1,040; slightly laevogyrate, up to - 1°, rarely higher; nD20O1,581 to 1,591; aldehyde content 65 to 76 p. c; eugenol content, determined with 3 p. c. sodium hydroxide solution, 4, commonly 6 to 10 p. c; soluble in 2 to 3 vol. or more of 70 p. c. alcohol.
In connection with 5 Seychelles cinnamon oils that were distilled in the islands, the following constants were observed3): d15O 0,943 to 0,967; AD - 2° 30' to - 5° 10'; nD20o 1,52843 to 1,53271; aldehyde content 21,7 to 35 p. c; eugenol content 6 to 15 p. c; with 10 vol. of 70 p. c. alcohol it does not form a clear solution but it is soluble in 0,6 to 5 vol. of 80 p. c. alcohol, becoming opalescent upon the additon of more alcohol.
Composition. R. Blanchet4) had already observed that upon distillation of Ceylon cinnamon two oils separate in the receiver, one of which is lighter, the other heavier than water, whereas Chinese cinnamon yields only a heavy oil. The older chemists studied only the heavier oil. J. Dumas and E. Peligot5) ascertained that, as is the case with cassia oil, cinnamic aldehyde is the principal constituent of Ceylon cinnamon oil. That the heavy oil of Ceylon cinnamon also contains eugenol was ascertained later. The amount of eugenol in the bark oil, as contrasted with that of the leaf oil, is small. It amounts to but 4 to 10 p. c.
1) Brit, and Colon. Druggist 54 (1908), 152; Report of Schimmel & Co. April 1909, 33.
2) Bull. Imp. Inst. 6 (1908), 111; Report of Schimmel & Co. Oct. 1908, 41.
3) Report of Schimmel & Co. October 1908, 41.
4) Liebig's Annalen 7 (1833), 163.
5) Ann. de Chim. et Phys. 57 (1834), 305. - Liebig's Annalen 14 (1835), 50.
All of the other constituents that have become known thus far have been found in the laboratories of Schimmel & Co.
Methyl-a-amyl ketone1). Upon treating fraction 163" with bisulphite a crystalline addition product was obtained from which pure methyl-/7-amyl ketone was separated. (M. p. of semicar-bazone 122 to 123; comp. vol. I, p. 434.)
Furfurol1). Its presence was indicated by means of the characteristic reaction with aniline hydrochloride.
l-a-Pinene1) (m. p. of nitrosochloride 102 to 103°; of nitrol-benzylamine 122 to 123°).
\-Phellandrene. Fraction 170 to 174° (aD - 5°4') yielded a nitrite that melted at 102°2). After repeated re-crystallization from acetic ester and methyl alcohol the melting point could not be raised above 103 to 104° ([a]D + 11°39)1). The inference to be drawn is that the phellandrene of Ceylon cinnamon oil is a mixture of l-a- and B-phellandrene in which the latter predominates.
Cymene1) (m. p. of hydroxyisopropyl benzoic acid 154 to 156°; of propenyl benzoic acid 161 to 162°).
Benzaldehyde1) (m. p. of phenylhydrazone 156°; of semicar-bazone 213 to 214°).
Nonylic aldehyde1) (oxidation to pelargonic acid, silver determination).
Hydrocinnamic aldehyde (phenyl propylic aldehyde)1). This aldehyde had previously not been found in nature. Being mixed with the nonylic aldehyde mentioned above, it could only be characterized by its semicarbazone melting at 126°. When the semicarbazone was heated with dilute sulphuric acid it developed the odor of phenyl propylic aldehyde. The melting point of the semicarbazone prepared from synthetic phenyl propylic aldehyde was found to be at 130 to 131°.