A new monoterpene alkaloid and other constituents of Plumeria acutifolia.

Phytochemical investigation of the methanolic extract of Plumeria acutifolia (Apocynaceae) leaves has led to the isolation and identification by spectroscopic means of a new monoterpene alkaloid, (R)-4'-((S)-1-hydroxyethyl)-5,6-dihydro-5' H-spiro[cyclopenta[C]pyridine-7,2'-furan)-5'-one, for which the name plumerianine was adopted, the iridoid 15-demethylplumeride, and three known triterpenes, i. e., lupeol, uvaol and ursolic acid.