RESUMO
A pyrolysis gas chromatography (Py-GC) technique has been used for the qualitative analysis of fumaric acid and itaconic acid as low-level monomers polymerized with other major monomers in emulsion polymers. In order for fumaric acid and itaconic acid to be detected through pyrolysis, the acids are derivatized with primary amines such as methylamine and ethylamine to form a cyclic imide. The detection of derivatized fumaric acid and itaconic acid is accomplished by atomic emission detection (AED). The structures of the derivatization-pyrolysis products have been elucidated by mass spectrometry.
RESUMO
The isolation and structure elucidation of the three new bisindole alkaloids, gabunamine, tabernamine, and 19,20-epoxyconoduramine, from Tabernaemontana johnstonii stem bark are described. The isolation of the seven known alkaloids, conodurine, conoduramine, gabunine, isovacangine, ibogamine, pericyclivine, and perivine, from the same source also is noted. The alkaloids gabunamine, gabunine, and tabernamine showed significant cytotoxicity against the P-388 cell culture system.
