Optimization of betulinic and ursolic acids and phenolics extraction from endemic Rosa pisiformis using Box-Behnken design in relation to cytotoxic activities.

Despite its important pharmacological bioactivities, betulinic acid is still primarily obtained through extraction from heartwood and bark or synthesized synthetically, with less than 3% efficiency. Our endemic rose species, Rosa pisiformis (Christ.) D. Sosn., which is a new alternative source of betulinic acid and traditionally valued for its medicinal properties, was collected from its natural distribution in Gümüşhane province. The plant's organs, such as root, stem, leaf and fruit were air-dried and pulverized. The compounds were separately extracted using three different solvents (ethanol, dichloromethane and hexane) with an optimized Box-Behnken method. The amounts of quercetin, rutin, catechin, betulinic, ursolic and oleanolic acids in roots, stems, leaves, and fruits were determined using HPLC-DAD techniques with standard substances. Optimisation data revealed a 65% solvent ratio and five-times maceration with 75 ml of solvents. The highest amounts of catechin were found in the leaves (DCM) as 15.61 µg/ml. Stems were rich in rutin (28.96 µg/ml) and quercetin (39.90 µg/ml). Betulinic acid content was determined for the first time in stems (hexane, 11.84 µg/ml) and roots (9.32 µg/ml). Their cytotoxic activities against prostate and lung carcinoma cells were evaluated using ABTS-assay, revealing that stems exhibited the highest activity, followed by leaves and roots.