Vern. :— Khen (Manipur) ; Soothan (Tel.); Thitsi (Burmese).
Habitat : — Manipur.
A large, deciduous tree. Bark dark grey. Wood dark red, with yellowish streaks turning very dark after long exposure ; very hard. Branchlets very stout, velvety. Petioles, underside of leaves, and panicles softly tomentose. Leaves obovate or oblanceolate ; 6-14 by 4-6in., base cuneate ; nerves 28-30 pair, stout, straight. Petiole flattened, winged, ½-1in. Panicles 1ft. long, peduncled. Flowers white, lax, ½in. diam. ; pedicels slender ; petals pubescent. Stamens many, 20-30. Calyx calyptriform, beaked, pubescent. Petals 5-6, eventually 2-4in. long, linear-oblong, obtuse, coriaceous, reticulated, gland-dotted, pubescent. Drupe red, glaucous ; ⅓-½in. diam., stalk thick, ⅓in. long, supported by the oblong, stellately-spreading, enlarged petals, 2-4in. long. Pedicel ½in. The tree yields the black Burmese lacquer or varnish from incisions made into the bark, while the tree is in leaf (Brandis).
Use : — The thick, greyish fluid, which is found in every 7 part of the plant, has been used in medicine as an anthelmintic with great success. If the juice be too much handled, it causes erysipelas-like swellings in certain constitutions, which are cured by the application of an infusion of teak wood.
Separation of Constituents.
Pure Thitsi extracted with hot alcohol.
[
I !
Residue shaken with dry ether Alcoholic extract contains Urushic acid
nd filtered. (about 85 per cent.)
Residue boiled with water. Filtrate, distilled, dried and again
I extracted with hot alcohol.
I I
Residue oily or fatty matter Extract contains last traces of
(smalt quantity). Urushic acid.
I I
Final residue is Diastatic matter Aqueous extract contains Gum.
(about 2 per cent). (Total (Gives the ordinary reactions
nitrogen in this diastase = 4*7 of gum arabic. Amount about
per cent.) 3 per cent.)
