Abstract
A collection of tropical Angiosperms, mainly collected in Amazonas and Apure States in Venezuela, has been examined for the presence of betaines and N-methylprolines, which were found in 58 out of the 65 species investigated. Betaine yields were generally low, but in the species that contained N-methylprolines, the yields of these compounds were generally in excess of 0.5% of the plant dry weight. N-methylprolines were isolated from four species of Loranthaceae, all four examined species of Miconia (Melastomataceae), Pleonotema variabilis (Bignoniaceae), Gustavia augusta and Lecythis corrugata (Lecythidaceae), and Machaerium humboldtianum (Fabaceae). Trans-4-hydroxyprolinebetaine was isolated in high yields from Amphilophium paniculatum, Arrabidaea candidans and Clytostoma binatum (Bignoniaceae), Combretum laxum (Combretaceae) and Gustavia augusta (Lecythidaceae).