521. Leptandra, N.F.—Leptandra.
The dried rhizome and roots of Veron'ica virgin'ica Linné.
BOTANICAL CHARACTERISTICS.—Stem erect, 2 to 6 feet high. Leaves whorled in 4's or 7's, very smooth, or sometimes slightly downy, lanceolate, serrulate. Spikes panicled; corolla small, pinkish, or nearly white; stamens much exserted.
HABITAT.—United States, east of the Mississippi.
DESCRIPTION OF DRUG.—Horizontal rhizome, 4 to 6 inches long, somewhat flattened, about the thickness of a quill, branched, generally broken into pieces an inch or more long; very hard and firm; from a light to a dark brown color; upper side marked with broad stem-scars, under side beset with the remnants of the thin, fragile, wrinkled rootlets. Fracture woody—bark thin, blackish, wood-circles one or two, yellowish, pith 6-rayed; tissue Surrounding pith irregular and angular; inodorous; taste bitter and acrid.
Powder.—Brown. Characteristic elements: Parenchyma of cortex, isodiametrical or elongated with spherical starch grains (2 to 4 µ in diam.) and brown resin; sclerenchyma with bast fibers and narrow, thick-walled stone cells; ducts with scalariform, spiral, simple pores; tracheids, numerous; outer wall of epidermal rootlets very thick; considerable cork from rhizome.
CONSTITUENTS.—Besides tannin, gum, and a small quantity of volatile oil, it contains a crystalline glucoside, the active principle, which should be termed leptandrin instead of the resin or resinoid called by that name; this resinoid is obtained by precipitating a concentrated alcoholic tincture with water; its action is probably due to a small amount of the crystalline glucoside mixed with it.
Preparation of Leptandrin.—Remove coloring matter from infusion by basic acetate of lead, excess of lead removed by Na2CO3. Treat resulting liquid with animal charcoal. Extract washed charcoal with boiling alcohol; evaporate; dissolve in ether to purify. Upon evaporation needle-shaped crystals are obtained which are bitter; soluble in water, alcohol, and ether. The eclectic leptandrin is made by precipitating concentrated alcoholic tincture with water, and is a mixture of inert matter with pure leptandrin.
ACTION AND USES.—Cholagogue cathartic. Dose: 15 to 60 gr. (1 to 4Gm.). The fluidextract, extract and vegetable cathartic pills formerly represented the drug (U.S.P. VIII).