Alkaloids and procyanidins of an Uncaria sp. from Peru.

The alkaloid and procyanidin composition of Uncaria sp. from eastern Peru, used in folk medicine was studied. Five alkaloids have been separated and identified as pteropodine, speciophylline, isopteropodine, uncarine F and isomytraphylline, all belonging to the oxindole group characteristic of the Rubiaceae. Moreover (--) epicatechin and four dimeric procyanidins A1, B1, B2 and B4 have been shown to constitute the polyphenolic fraction of the plant extract.