Source, Etc

Storax is a balsam obtained from the trunk of Liquid-ambar orientalis, Miller (N.O. Hamamelideoe), a tree of medium size forming forests in the south-west of Asiatic Turkey.

Neither the bark nor the wood of the tree possesses the agreeable odour of storax, and under norma] conditions this substance is not produced in any part of the plant. In the early summer, incisions are made or the bark is beaten but not so vigorously as to kill it; a formation of storax takes place, and the balsam soaks into the wounded bark, which is stripped off in the autumn. From the bark thus saturated the balsam is obtained by pressing it, the residue being subsequently mixed with boiling water (or boiled with water) and again pressed. The liquid balsam thus obtained forms the storax of commerce, whilst the pressed bark was formerly an article of commerce, under the name of Cortex Thymiamatis. The latter, coarsely ground and mixed with storax, formed ' Styrax calamitus,' under which name at the present time a factitious mixture is generally sold.

Although the bark of the tree contains secretion ducts these do not take part in the production of storax, which is secreted in schizogenous ducts in the young wood; these, by the breaking down of intervening tissue, form schizolysigenous cavities from which the balsam exudes into the wounded bark. The secretion is therefore purely pathological, and it is produced in the young wood, subsequently finding its way thence into the bark, with which it is removed when the latter is stripped off.

Description

Crude storax is a greyish, semi-fluid, viscid substance with an agreeable, aromatic, balsamic odour and a sharp, pungent taste. It is rather heavier than water, and contains usually vegetable debris, amongst which numerous bast fibres may be found. By drying it loses from 17.4 to 25.8 per cent. of water.

The crude drug is purified by dissolving it in three or four times its volume of hot alcohol, filtering, and removing the alcohol by gentle evaporation, care being taken to lose as little of the volatile constituents as possible. From 13 to 18 per cent. of the crude storax is insoluble in alcohol, the residue consisting principally of vegetable debris associated with inorganic matter ('Pharmacographia'). According to Evers (1896) storax contains from 6 to 9 per cent. of a greyish substance insoluble in alcohol, probably a resin ester of cinnamic acid.

Thus purified, storax is a semi-transparent, yellowish brown, semi-liquid balsam, entirely soluble in alcohol, ether, chloroform, and carbon disulphide. It should have a specific gravity of 1.109 to 1.114 at 100°.

Constituents

Purified storax consists of a resin mixed with an oily liquid.

The resin is composed of storesinol partly free, partly combined with cinnamic acid. Storesinol is a white odourless amorphous substance which, however, forms a crystalline potassium compound.

The oily liquid contains styrol (phenylethylene, a colourless aromatic liquid), ethyl cinnamate, phenylpropyl cinnamate (odourless liquid) cinnamyl cinnamate (= styracin, odourless crystals), vanillin, and free cinnamic acid.

The approximate composition of storax, which, however, varies considerably, may be seen from the following table:

Free cinnamic acid ...

17

to

23

per cent.

Esters of cinnamic acid ..

24

to

25

,,

Water ....

14

to

21

,,

Resin ....

36

,,

Purified storax may contain as much as 47 per cent. of cinnamic acid (free and combined), and is, in this respect, one of the richest drugs known.

Uses

Storax is a local and remote stimulant and antiseptic, resembling in these respects balsam of Peru, benzoin, etc. It is now seldom used.

Adulteration

The quantitative composition of storax is so variable that its purity can with difficulty be ascertained.

The acid value should vary between 60 and 90 and the ester value between 100 and 146. It should contain not less than 20 per cent. of total cinnamic acid when tested by the official process. Storax of good quality yields often from 25 to 30 per cent. of acid.

Much of the storax imported, especially from Trieste and Marseilles, since 1907 was very deficient in cinnamic acid, the percentage dropping to 2 or 3. Such balsam had been apparently deprived of some of its most valuable constituents (particularly cinnamyl alcohol and cinnamic acid) which were in demand for the perfumery trade.

Allied Drugs

American storax or sweet gum is a transparent, yellowish, viscous liquid obtained from L. Styraciflua, Linne. It has been found to contain cinnamein 22.86 per cent., resin esters 34.76 per cent., resin acids 2.11 per cent., free cinnamic acid 12.63 per cent., total cinnamic acid 28.02 per cent. It has been recommended as a substitute for the Turkish.