Source, Etc

The dried root and stem of Ipomoea Turpethum, Robert Brown (N.O. Convolvulaceae), a native of India, Ceylon, the Malay Archipelago and N. Australia.

Description

Turpeth occurs in pieces of very varying length and thickness; they are often 10 to 20 cm. long and 1 to 5 cm. wide, deeply wrinkled longitudinally, and of a dull grey or brown colour; sometimes the bark has been slit on one side and the central wood removed. Fracture short, the wood in old specimens in several concentric circles; vessels very large; medullary rays wide; in the bark resin cells and frequently abnormal wood bundles. Odour slight, taste nauseous but slowly developed.

Constituents

Turpeth contains from 5 to 10 per cent. of resin, part of which is soluble and part insoluble in ether. The ether-soluble resin is a mixture of a- and β-turpethein, the ether-insoluble resin is turpethin. Turpeth resin has not yet been thoroughly examined; a-turpethein appears to be a rhamnoside; β-turpethein a glucoside. Further research will probably show a complex composition analogous to that of scammony resin, jalap resin, etc.

Uses

The drug has long been used in India as a purgative.