Opopanax.—A concrete juice or oleo-gum-resin of Opopanax chironium Kch. (Pastinaca Opopanax L., Fam. Umbelliferae). This species of parsnip has a thick, yellow, fleshy, perennial root, which sends up annually a strong branching stem, rough near the base, about 2 cm. in thickness, and from 1 to 3 m. in height. The leaves are variously pinnate, with long sheathing petioles, and large, oblong, serrate leaflets, of which the terminal one is cordate, others are deficient at their base upon the upper side and the whole are hairy on their under surface. The flowers are small, yellow, and form large flat umbels at the termination of the branches. The plant is a native of the Levant, and grows wild in the south of France, Italy and Greece. When the base of the stem is wounded, a juice exudes, which, when dried in the sun, constitutes the opopanax of commerce. Some authors state that it is obtained from the root. A warm climate appears necessary for the perfection of the juice, as that which has been collected from the plant in France, though similar to opopanax, is of inferior quality. The drug is brought from Turkey. It is said to come also from the East Indies; but Ainslie states that he never met with it in any Indian medicine bazaar. The method of its production is not known with any certainty.
It is sometimes in tears, but usually in irregular lumps or fragments, of a reddish-yellow color, speckled with white on the outside, paler within, and, when broken, exhibiting white pieces intermingled with the mass. Its odor is strong, peculiar, and unpleasant, its taste bitter and acrid. Its sp. gr. is 1.622. It is inflammable, burning with a bright flame. It is a gum-resin, with an admixture of other ingredients in small proportion. Pelletier found in it gum, starch, wax, malic acid, lignin, a volatile oil, and traces of caoutchouc. Subsequently, Tschirch found opopanax to consist of resin, 19 per cent., ethereal oil, 6.5 per cent.; gum and plant tissues, 70 per cent.; water and loss, 4.5 per cent. (A. Pharm., 1895, 209.) Schimmel states that the oil consists of an alcohol with a sesquiterpene as the chief constituent. (Schim. Rep., 1904, 67.) Water by trituration dissolves about one-half of the gum-resin, forming an opaque milky emulsion, which deposits resinous matter on standing, and becomes yellowish. Both alcohol and water distilled from it retain its flavor; but only a very minute proportion of oil can be obtained in a separate state. Opopanax was formerly employed, as an antispasmodic and deobstruent, in hypochondriasis, hysteria, asthma, and chronic visceral affections, and as an emmenagogue; but it is now scarcely ever used. Dose, ten to thirty grains (0.65-2.0 Gm.).
The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.