Pterocarpi Lignum, B.P. Red Sanders Wood.
Synonym.—Red Sandal Wood.
Red sanders wood (Santalum Rubrum, U.S.P., Red Saunders) is the heartwood of Pterocarpus santalinus, Linn. I. (N.O. Leguminosae), a small tree indigenous to India. The wood is imported in irregular billets, which have been deprived of their bark and sapwood. They are of a deep red colour, the transverse section exhibiting alternating darker and lighter zones. The wood is hard, and for pharmaceutical use is generally obtained as a coarse powder, or in small, hard, splintery raspings. It is almost odourless, and has a somewhat astringent taste. It yields from 1 to 2 percent. of ash on incineration.
Constituents.—The chief constituent of the wood is the red colouring matter santalin (santalic acid), which forms microscopic prisms, melting at 104°. It is insoluble in water, but yields a blood-red solution with alcohol, yellow with ether, and violet with ammonia and caustic alkalies. The wood also contains santal, pterocarpin, and homopterocarpin, three colourless, crystalline substances.
Uses.—Red sanders wood is employed solely for its colouring matter, which is precipitated by mineral acids.