Pao-Pereira bark. Pereiro bark. Geissospermum laeve.
Pao-Pereira Bark. Pereiro Bark.—Under this name a bark is employed in Brazil as a febrifuge. It is supposed to be the product of Geissospermum laeve (Veil.) Baill. (Fam. Apocynaceae). O. Hesse has found an alkaloid, geissospermine, C19H24N2O2+H2O, in it (see P. J., viii, 648), but he seems to have been preceded in this discovery by Santos. (A. J. P., 1878, 184.) Peretti has discovered in the root a second alkaloid, pereirine, C19H24N2O, which, according to Guimaraes (B. M. J., vol. i, 1887), in sufficient doses causes paralysis with elevation of temperature, ending in death. It has been given to man as an antiperiodic in doses of thirty grains (2.0 Gm.) a day. (See also A. J. P., 1886, 278.) Later a third alkaloid, vellosine, C23H28N2O4, was found. This forms colorless, crystals, melting at 189° C. (372.2° F.), insoluble in water, easily soluble in alcohol and ether. In concentrated nitric acid it dissolves with a purplish-red color, which is very stable.