Anthraquinone profile and chemical fingerprint of Rhamnus saxatilis L. from Italy

Several species belonging to the genus Rhamnus (Rhamnaceae), comprising ones among which are found the most typical plants of the Italian flora, are known to contain biologically active anthraquinone secondary metabolites. Although several Rhamnus species were so far investigated, no information is available concerning the content and relative abundances of anthraquinones in R. saxatilis. In this study we used a simple, reliable, and accurate analytical method to determine the anthraquinones in bark of R. saxatilis. This allowed us also to trace a comparative study on the efficacy of different extraction solvents in ultrasonication time dependent assays. Separation and quantification of anthraquinones were accomplished using a C18 column with the mobile phase of H2O:methanol (40:60, v/v, 1% formic acid) at a flow rate of 0.7 mL/min and a detection wavelength of 254 nm, while the qualitative analyses were also achieved at a wavelength of 435 nm.Finally, the described HPLC method, was used to obtain a specific chemical fingerprint for this species in comparison with other species from the same family.