New alkaloid from Lobelia portoricensis urban

A major alkaloid has been isolated from the leaves of Lobelia portoricensis Urban. Alkaloids are extracted with ether in alkaline ammoniacal solution, an average of 1.25 percent in the dried leaves. The crystalline alkaloid has a melting point of 115–116°, the hydrochloride, m.p. 187–188°, perchlorate, m.p. 156–158°, and the picrate, m.p. 175–176°. The new alkaloid showed the same sensitivity to reagents as lobeline. Paper chromatography, ascending process, was employed. Stationary phase consisted of formamide, ammonium formate, and formic acid; the mobile phase, equal parts of benzene and chloroform; Rf 75. Infrared absorption spectra showed a R─CO─aromatic organization and the presence of a ─NH group; no CH3 or OH group as in lobeline. The empirical formula is C21H23NO23. The formula is shown in structure I. The new alkaloid was found to stimulate the respiratory center.