Oleum Galangae. - Galgantol. - Essence de Galanga.
Origin and Production. Alpinia officinarum, Hance, of the family Zingiberaceae, is originally indigenous to the Chinese island of Hai-nan, where it is now cultivated, also on the opposite island of Leitschou, and the neighboring coast and in Siam. It is official in the German Pharmacopoeia as Rhizoma Galangae. Upon distillation of the comminuted root 0,5 to 1 p.c. of volatile oil is obtained.
Properties. Galangal oil is a greenish-yellow, not very limpid oil with a camphoraceous odor and a taste which is at first bitter, and later, somewhat cooling.
1) On some further constituents of the essential oil of Kaempferia Galanga, L. Koninklijke Akademie van Wetenschappen te Amsterdam. May May 1902, 618.
The specific gravity lies between 0,915 and 0,921; the angle of rotation between - 1°30' and - 5° 30'; nD20o1,476 to 1,482; A. V. up to 2; E. V. after acetylation 40 to 45. It is miscible with one half and more vol. of 90 p.c. alcohol; of 80 p.c. alcohol 10 to 25 vol. are required to form a clear solution.
Composition. According to Schindelmeiser1), the lowest fraction consists of d-a-pinene (nitrosochloride, nitrolpiperidide). Cineol (hydrobromide2)) is another constituent to which the oil owes its camphor-like odor. Upon shaking the oil with sodium hydroxide solution, P. K. Horst3) isolated about 75 p.c. of eugenol (m. p. of benzoyleugenol 69 to 70,5°). From fraction 230 to 240° (d20o0,932; aD20o - 27°21'; nD20o 1,4922) Schindelmeiser4) obtained a viscid hydrochloride which boiled at 145 to 150° (10 mm.), congealed when cooled, and after repeated crystallization from alcohol and water melted at 51°. A chlorine determination revealed the formula C15H24.2Hc1. Inasmuch as heretofore no sesquiterpene dihydrochloride of the above melting point has been observed, the hydrocarbon in question appears to be a new one. In the higher boiling fractions (b.p. 274 to 276°) the presence of cadinene is suspected.