Iridoids from Loasa acerifolia.

In the course of preliminary chemotaxonomic studies on Loasaceae from South and Central America, 30 species from 6 genera were screened by chromatographic means. From the aerial parts of Loasa acerifolia Dombey, the novel trimeric and dimeric iridoid glucosides acerifolioside and tricoloroside methyl ester, consisting of loganin and secoxyloganin moieties, were isolated. The structures were primarily elucidated by NMR spectroscopy. Loganin, loganic acid, rutin, scopoletin and chlorogenic acid were identified by cochromatography with reference compounds.