Notes on Cananga Oil, or Ylang-Ylang Oil.
BY PROFESSOR F. A. FLÜCKIGER.
Translated from "Arch. der Phar.," Jan., 1881, Band xv, pp, 24 to 31, by FRED. B. POWER.
This oil, on account of its pleasant odor, which by most observers is designated as very exquisite, has acquired some reputation, so that the following notes upon the same, and the plant from which it is derived, may be of general interest.
The tree whose flowers furnish the oil known under the name of Ylang-Ylang, or Alanguilan, is Cananga odorata, Hooker fil. and Thomson, from the family of Anonaceae, for which reason it is also termed in many price lists Oleum Anonae, or Oleum Unonae. It is not known to the author whether the tree can be identified in the old Indian and Chinese literature; in the Occident it was first named "Arbor Saguisan" by Ray, and was so called at that time in Luçon. Rumph gave a detailed description of the Bonga Cananga (Tsjampa of the Javanese), as the Malayan designation of the tree is expressed. Rumph's illustration, however, is faulty. Lamarck has made further short reports thereon under Canang odorant and Uvaria odorata. According to Roxburgh, the plant was brought in 1797 from Sumatra to the botanical garden of Calcutta. Dunal gave of Uvaria odorata, or properly Unona odorata, as corrected by himself, a somewhat more detailed description in his "Monographie de la famille des Anonacees," which is chiefly a repetition of the statements of Rumph.
We are finally indebted for a very fine illustration of the Cananga odorata to the magnificent Flora Javae of Blume; a copy of this, which in the original is handsomely colored, is reproduced with this notice. That the illustration is correct may be accepted from the fact of the authors having seen numerous specimens of the cananga by De Candolle in Geneva, also in the herbarium of Delessert. The unjustifiable appellation Unona odoratissima, which has passed inaccurately enough into many writings, originated with Blanco, who, by his description of the intense perfume of the flowers, which in a closed sleeping apartment produces headache, permitted himself to be drawn to the employment of the superlative odoratissima. Baillon designates as Canangium the section of the genus Uvaria, from which he contends the Ylang-Ylang tree should not be separated. The notice of Maximowicz, "Ueber den Ursprung des Parfüms Ylang-Ylang," contains only a confirmation of the derivation of the same from Cananga.
Cananga odorata is a tree attaining a height of 60 feet, with few but richly ramified branches. The leaves, which are arranged in two rows, on short petioles and longly pointed, attain a length of 18 centimeters and a breadth of about 7 cm.; the surface of the leaf is somewhat firm, and only on the under side, along the nerves, slightly downy. The beautiful and imposing flowers amount to as many as four, upon short pedicels. The three lobes of the leathery calyx are finally turned back. The six lanceolate flat petals grow to a length of 7 cm. and a width of about 12 millimeters, are longitudinally nerved, of a greenish color, and, when dried, dark brown. The somewhat bell-shaped, gracefully declining flowers, present a quite pretty aspect, although the flowers of other related plants are far more attractive.
The filaments of Cananga are very numerous; the somewhat elevated receptacle is flatly depressed at the vertex. The green berry-like fruit consists of from 15 to 20 distinct carpels, on rather long pedicels, and enclosing from 3 to 8 seeds, arranged in two rows. The umbel-like inflorescence is situated in the axils of the leaves, or arises from the nodes of leafless branches. The fleshy portion of the fruit is sweetish and aromatic; the flowers possess the most excellent perfume, which is often compared with the hyacinth, narcissus and clove.
Cananga odorata, according to Hooker and Thomson and Bentham and Hooker, is the only species of this genus; the plants, which were formerly classed together with it under the name of Unona or Uvaria, and of which some likewise have flowers possessing a pleasant odor, are retained in these two genera, which are quite rich in species. From Uvaria the Cananga is distinguished by the valvate corolla, and from Unona by the double-rowed arrangement of the seed.
Cananga odorata is distributed throughout entire southern Asia, but principally as a cultivated plant. In the primitive forest the tree grows much higher, but the flowers, according to Blum, are almost odorless. In its habitus Cananga resembles Michelia champaca, Lin., nat. ord. Magnoliaceae, a tree of India much admired on account of the very pleasant odor of its yellow flowers. Among the flowers which exhale a pleasant perfume, and to which the Javanese in this respect are much accustomed, those to which the preference is given by them, are in the first line the "Tjempaka," Michelia champaka, and the ""Kenangga wangi," Cananga odorata.
It is not known to the author whether the oil of Cananga was prepared in former times; it appears to have first reached Europe about 1864, and in Paris and London its choice fragrance found full recognition. The very small amounts which were first imported from the Indian Archipelago were soon followed by somewhat larger consignments from Manilla, where German pharmacists occupied themselves with the distillation of the oil.
Oscar Reymann and Adolf Röusch, in Manilla, exhibited the Ylang-Ylang oil at Paris in 1878; the former had also in addition the Cananga flowers themselves. The oil, standing by its side of the flowers of the previously mentioned Michelia champaca, competes with the Cananga oil, or Ylang-Ylang oil, in respect to fragrance. To what extent the latter has found favor is difficult to judge, although the reduction in price which the same has experienced would speak, probably, for a somewhat larger demand; at present it is to be had in Germany for about 600 marks (150 dollars) per kilogram. (According to information furnished by Mr. Reymann, there are annually consumed in Paris, Nizza and Grasse about 200 kilograms, in London about 50 kilograms, and as much in Germany (Leipsic, Berlin, Frankfurt).) As the Cananga tree may be cultivated very easily in all warmer countries, and is probably everywhere provided with the same delightful fragrance of the flowers, it must be possible to furnish the oil much cheaper, although the amount obtained is always quite small (25 grams of oil from 5 kilograms of flowers, according to Reymann). It is a question whether the tree would not flourish, for example, in Algeria, where already so many exotic perfume plants are cultivated.
According to Guibourt, the Macassar oil, which was at one time highly prized in Europe as a hair oil, is cocoa nut oil digested with the flowers of Cananga odorata and Michelia champaca, and colored yellow by means of curcuma. In India, ointments of this kind have been in use for a very long time.
The name Cananga is found, moreover, also in Germany, in former times. An Oleum destillatum Canangae is mentioned by the Leipsic apothecary J. H. Linck, under "einigen neuen Exoticis" in the "Sammlung von Natur und Medicin, wie auch hierzu gehörigen Kunst- und Literatur-Geschichten, so Anno 1719 in Schlesien und anderen Landern begeben," Leipzig and Budissin, 1719. As, however, the fruit of the same tree, which was sent at the same time with this Cananga oil, is described by Linck as exceptionally bitter, it cannot probably here refer to the present Cananga odorata, the fruit pulp of which is emphatically designated by Rumph and by Blume as sweetish. Furthermore, an Oleum Canangae, Camel straw oil, held a place, in 1765, in the tax of Bremen and Verden. It may remain undecided whether this oil was really derived from camel straw, from the beautiful grass Andropogon laniger.
From a chemical standpoint, the Cananga oil has become of interest through the information furnished by Gal that it contains benzoic acid, and without doubt in the form of a compound ether. As well as the author remembers the literature of the volatile oils at the moment, this occurrence of an ether of benzoic acid in nature is an isolated one (not considering Peru balsam and Tolu balsam), although of itself it cannot be surprising, and presumably will be often detected. The author induced Mr. Adolf Convert to examine the Ylang-Ylang oil in this direction. The oil does not change litmus paper moistened with alcohol; at 170°C. a small portion distilled over, but the mercury rose gradually to 290°C., and at a still higher temperature decomposition took place. That the portions which passed over below 290°C. had a strongly acid reaction pointed already to the presence of compound ethers. Mr. Convert boiled 10 grams of the oil with 20 grams of alcohol and 1 gram of caustic potassa for one day in a flask provided with an inverted condenser. The alcohol was finally removed by distillation, the residue supersaturated with dilute sulphuric acid, and together with much water subjected to distillation until the distillate scarcely showed an acid reaction. The liquid which had passed over was neutralized with barium carbonate, and the filtrate concentrated, whereupon it furnished crystals which were recognized as nearly pure acetate. The acid residue, which contained the potassium sulphate, was then shaken with ether; after the evaporation of the latter there remained a crystalline mass of an acid reaction, which assumed a violet color with ferric chloride. This reaction, which is probably to be attributed to a phenol, was not shown after the crystalline mass had been recrystallized from boiling water; the aqueous solution of the purified crystalline scales then gave with ferric chloride simply a slight flesh-colored precipitate. The crystals melted at 120°C.
For the confirmation that the substance was benzoic acid, Mr. Convert boiled the same with water and oxide of silver, and dried the scales obtained on cooling over sulphuric acid. 0.0312 gram of the crystals gave upon combustion 0.0147 gram of silver, or 47.1 per cent.; benzoate of silver contains 46.6 per cent. of metal; the crystals were accordingly, in fact, benzoate of silver. For the separation of the alcoholic constituent, which is present apparently in not very considerable amount, in the form of a benzoic ether, much more Ylang oil would be required.
Besides the benzoic ether and a supposed above-mentioned phenol, an aldehyd or ketone is also indicated in the Ylang oil, in so far as by shaking the latter with acid sodium sulphite the formation of a very small amount of crystals was observed. That Gal did not obtain the same must remain unexplained. Like the benzoic acid, the acetic acid is also undoubtedly present in the Cananga oil in the form of a compound ether.