Five new alkaloids from the leaves of Remijia peruviana

Three new indolylquinuclidine-type alkaloids, remijinine (1), epiremijinine (2), and 5-acetyl-apocinchonamine (3), and two new cinchonine-derived alkaloids, N-acetyl-deoxycinchonicinol (4) and N-acetyl-cinchonicinol (5), as well as the known alkaloids quinamine, conquinamine, cinchonine, and quinidine were isolated from the leaves of Remijia peruviana. The structures of the new alkaloids were elucidated on the basis of spectroscopic analysis, including homonuclear and heteronuclear correlation NMR experiments (COSY, ROESY, HMQC, and HMBC). The relative configuration at C-7 for remijinine (1) and, in consequence, for epiremijinine (2) was established by X-ray crystal structure analysis of the former.