Page:Indian Medicinal Plants (Text Part 1).djvu/603

Rh Uses : — The root is astringent, tonic, and antiseptic, but it is undeservingly neglected in modern practice (British Flora Meidca).

This plant does not seem to be used for medicinal purposes in India.

Source and composition of the essential oil of Herb Bennett Root. A new glucoside and Enzyme.

The dried root of Herb Bennett (Geum urbanum) has a feeble odour resembling that of cloves. If the plant be carefully plucked so as to leave the root intact, there is no manifestation of the characteristic odour, but this is at once detectable when the root is crushed between the fingers. The explanation of this phenomenon was established by the following experiments.

By extraction of the fresh root with boiling alcohol of 95°, distillation of the extract under reduced pressure, extraction of all the residue with alcohol, and precipitation of the solution by excess of ether, a substance is obtained which is odourless, but however contains the substance which gives rise to odoriferous principle. This proves to be eugenol.

Another portion of the root was macerated with sand and extracted with cold alcohol of 90°. The residual powder, which contains an enzyme, was dried at 30°. On adding to an aqueous solution of the first substance, a little of the ferment powder, a distinct odour of cloves is at once evident. If the ferment powder is previously heated in boiling water, the effect is not observable. It is concluded from these observations that the odoriferous principle does not exist free in the Herb Bennett root, but is produced from some other substance present by the action of an enzyme. The substance is a glucoside ; on addition of the enzyme to its aqueous solution, the reducing power and the rotary power both gradually increase.

The active enzyme is characteristic, the resolution of the glucoside is not effected by emulsin, invertase, onor by the enzyme of Aspergillus niger. It cannot be extracted by treatment of the roots with water.

The glucoside can be isolated in globular crystals by addition of ether to the alcoholic solution. The term gein is proposed for the glucoside, and gease for the enzyme.- J. Ch. S. 1905 A II 345.

Vern. : — Gunglu junglic (Pers.); gogjemool (Cashmere).

Habitat : — Subalpine to Alpine Himalaya; from Kashmir to Sikkim.

Rootstock stout, woody. Leaves pinnatisect, hairy, 4-12in., linear-oblong ; leaflets ½-lin., close and imbricating or scattered, uniform or the alternate smaller, terminal orbicular, all lobed and coarsely crenate, upper all adnate by a broad base.