HIGHLY OXYGENATED COUMARINS FROM PELARGONIUM SIDOIDES

Article abstract of DOI:10.1016/0031-9422(95)00166-5

The sample of natural simple coumarins is extended by discovery of the highly oxygenated representatives 6,8-dihydroxy-7-methoxycoumarin, 6,7,8-trihydroxycoumarin, 6,8-dihydroxy-5,7-dimethoxycoumarin, and 7-acetoxy-5,6-dimethoxycoumarin.They are accompanied in the roots of Pelargonium sidoides by the widely occuring scopoletin, associated with the uncommon analoges 5,6,7-trimethoxycoumarin, 7-hydroxy-5,6-dimethoxycoumarin (umckalin), and 5,6,7,8-tetramethoxycoumarin (artelin), these being reported from a plant source for the second time.The structures of these compounds were established from chemical and spectroscopic studies.Differentiation between oxygenation patterns is discussed on the basis of chemical shift data.