A validated HPLC-UV method for the analysis of galloylquinic acid derivatives and flavonoids in Copaifera langsdorffii leaves

Copaifera langsdorffii Desf. (Fabaceae, Caesalpinioideae), popularly known as “copaiba” or “pau d'óleo”, is a species of tree that is found throughout Brazil. The leaves of this tree are used in folk medicine to treat kidney stones. Galloylquinic acid derivatives and flavonoids are the main secondary metabolites found in C. langsdorffii leaves and are likely to be responsible for the effectiveness of this treatment. As an attempt to produce a phytotherapic, we have developed a reliable HPLC-UV method for the quality control of C. langsdorffii leaves. Phenolic compounds were extracted from C. langsdorffii leaves using 70% aqueous ethanol as the extraction solvent. HPLC-UV analyses were carried out on a Synergi Polar-RP column (100 × 3.0 mm, 2.5 μm), and the mobile phase was made up of formic acid-water (0.1:99.9, solvent A), and isopropanol-methanol-acetonitrile (5:40:60, solvent B). The elution gradient was A:B (90:10 to 85:15) in 8.0 min, followed by A:B (85:15 to 64:36) up to 30.0 min, using a flow rate of 0.7 mL/min, and UV detection at 280 nm. This method was used to quantify nine galloylquinic acid derivatives and two flavonoids, which gave a good detection response and linearity in the range of 1.88-110.0 μg/mL. Furthermore, the detection and quantification limits ranged from 0.070 to 0.752 μg/mL, and 0.211-2.278 μg/mL respectively, with a maximum RSD of 4.18%. The method is reliable for the quality control of C. langsdorffii raw material, its hydroethanolic extract, and could potentially be used to quantify these compounds in other Copaifera species.