Isolation of unstable alkaloids from Erythrophleum chlorostachys (Leguminosae)

Abstract

Unstable 2-methylaminoethyl esters from E. chlorostachys can be isolated with careful pH control and then manipulated as their stable hydrochlorides. A large-scale extraction and counter- current distribution separated two new crystalline alkaloid hydrochlorides, namely norerythrostachaldine hydrochloride, C₂₃H₃₇NO₅,HCl, and a second salt, C₂₄H₃₇NO₇,HCl. Four new monoacetates are tentatively identified as the 3β-acetoxy derivatives of the two new alkaloids, norerythrostachamine, and norerythrophlamine. Norerythrophlamine has been isolated for the first time as its crystalline hydrochloride.