Analysis of flavonoids in Rubus erythrocladus and Morus nigra leaves extracts by liquid chromatography and capillary electrophoresis

This study uses high performance liquid chromatography and capillary electrophoresis as analytical tools to evaluate flavonoids in hydrolyzed leaves extracts of Rubus erythrocladus Mart., Rosaceae, and Morus nigra L., Moraceae. For phytochemical analysis, the extracts were prepared by acid hydrolysis and ultrasonic bath and analyzed by high performance liquid chromatography using an ultraviolet detector and by capillary electrophoresis equipped with a diode-array detector. Quercetin and kaempferol were identified in these extracts. The analytical methods developed were validated and applied. Quercetin and kaempferol were quantified in R. erythrocladus, with 848.43±66.68μgg−1 and 304.35±17.29μgg−1, respectively, by HPLC-UV and quercetin, 836.37±149.43μgg−1, by CE-DAD. In M. nigra the quantifications of quercetin and kaempferol were 2323.90±145.35μgg−1 and 1446.36±59.00μgg−1, respectively, by HPLC-UV and, 2552.82±275.30μgg−1 and 1188.67±99.21μgg−1, respectively, by CE-DAD. The extracts were also analyzed by ultra-performance liquid chromatography coupled with a diode-array detector and mass spectrometer (MS), UPLC-DAD/MS.