Buteae Gummi, I. C. A., Butea Gum.
Butea gum is a dried astringent juice obtained from incisions in the stem of Butea frondosa, Roxb. (N.O. Leguminosae), a tree which grows in India. Butea gum is sanctioned for use in India and the Eastern Colonies as a substitute for East Indian, Malabar, or Madras kino, in making official preparations for which kino is directed to be used. The gum occurs in commerce in small, irregular, angular fragments, to one side of which dull, buff-coloured portions of the cork and cortex of the stem sometimes adhere. When fresh the gum is brittle, vitreous, ruby-red in colour, and transparent in small fragments; but on keeping it becomes tougher, dull, opaque, and nearly black. It is partially soluble in water, and yields about 40 per cent. to alcohol. It is readily reduced to a reddish powder, and has an astringent taste. For use in medicine the drug should be free from adhering portions of the stem.
Constituents.—The chief constituents of butea gum are from 15 to 62 per cent. of kinotannic acid, and 3.5 to 11 per cent. of other soluble matters, while the insoluble matter may vary from 10 to 46 per cent.
Action and Uses.—Butea gum possesses astringent properties, and may be used for similar purposes to kino.