Chemical Investigation of the Constitutive Phenolics of Rosa arabica; the Structure of a New Dimeric Phenolic Glycoside

The aqueous ethanolic whole plant extract of Rosa arabica was found to contain the new natural dimeric phenolic compound, ellagic acid 3,3'-dimethyl ether $4-O-{\alpha}-rhamnopyranoside$, 9, along with ten known phenolic metabolites (1-8, 10 and 11). Structures of all compounds (1-11) were established by routine methods of analysis and confirmed by FAB-MS, $^1H\;and\;^{13}C$ NMR spectral analysis.