OPOPANAX OIL

Description

Opopanax is an oleo-gum-resin that oozes through incisions made on the bark of the tree. The exudate hardens on exposure to air, forming resinous, tear-shaped, more or less regular lumps approximately the size of a nut; these are detached from the bark and used for the manufacture of the essential oil and other derivatives. The trees are native to Somaliland. Once opopanax resin was obtained from O. chironium Koch; today the entire production of resin is obtained from C. erythraea Eng. var. glabrescens.
O. chironium crude resin was offered in the form of regular, tearshaped lumps of a brilliant red color. They were rather soft, shiny, and easily groundable. The strong, aromatic odor was reminiscent of costus and lovage.
The crude oleoresin has a reddish-brown, or sometimes yellowishbrown, color and sweet, balsamic, slightly spicy odor reminiscent of myrrh. The material contains 50 to 80% of a water-soluble gum, 15 to 40% alcohol-soluble resin, and 5 to 9% essential oil. The product is also known as bisabol or sweet myrrh. The adulteration is readily detectable, since opopanax tears in benzene do not react; myrrh tears yield a violet color in the presence of bromine vapors. The oleo-gum-resin exudate is the part used. Opopanax has a fresh, balsamic odor reminiscent of myrrh.
The essential oil is obtained by steam distillation of the crude resin in approximately 3.5 to 10% yields. It is a yellow to greenishyellow liquid with an intense, warm, balsamic odor. The oil tends to resinify on exposure to air. Its main constituents include bisabolene (C15H24) and a mixture of alcohols.
The derivatives are resinoid and resin absolute. The resinoid, prepared by solvent extraction, is a semisolid mass. To prepare a pourable product, usually a high-boiling, odorless solvent is added prior to evaporation of the extractive solvent. The resin absolute is prepared by direct alcoholic extraction of the crude resin.

Chemical properties

Opopanax oil and opopanax resinoid are obtained from the resin of Commiphora erythraea Engl. var. glabrescens Engl. or closely related species such as Commiphora guidotti Chiov. and Commiphora kataf (Forsk.) Engl., trees growing in Somalia (Burseraceae).The resinoid is prepared by solvent extraction, and steam distillation of the resin gives the essential oil, which is a yellow to greenishyellow liquid with a warm, sweet, balsamic odor.
d²⁵₂₅ 0.865–0.932; n²⁰_D 1.488–1.504; α²⁰_D ?32 ° to ?9 °; acid number: max. 4; saponification number: 4–20; solubility: 1 vol in 10 vol of 90% ethanol; solutions are occasionally turbid. Sesquiterpene hydrocarbons such as α-santalene, (E)-α-bergamotene, and (Z)-α-bisabolene make up the main constituents of opopanax oil.
Opopanax oil and resinoid are used in perfumecompositionswith oriental characteristics, the resinoid also for its fixative properties.

Chemical properties

The oil is obtained by steam distillation of the crude resin in approximately 3.5 to 10% yields. It has an intense, warm, balsamic odor. The oil tends to resinify on exposure to air.

Physical properties

The oil is a yellow to greenish-yellow liquid.

Definition

Extractives and their physically modified derivatives. Commiphora erythraea, Burseraceae

Essential oil composition

Its main constituents include bisabolene (C15H24) and a mixture of alcohols.