Pelargoniins, new ellagitannins from Pelargonium reniforme.

The range of natural ellagitannins is extended by identification of five new metabolites with 1C4 glucose core, designated as pelargoniins A-D and isocorilagin, and the new phyllanthusiin E methyl ester. They are accompanied in the aerial parts of Pelargonium reniforme by two known structurally related metabolites, corilagin and phyllanthusiin C, two phenolcarboxylic acids, brevifolincarboxylic acid and phyllanthusiin E, the gallotannin 1-O-galloyl-beta-D-glucopyranose, and the ellagitannins strictinin and isostrictinin having a 4C1-glucose core. The structures of these compounds were established from spectroscopic studies. This is the first example of the co-occurrence of ellagitannins with 4C1 and 1C4 glucopyranose core demonstrated for a member of the Geraniaceae.