Determination of Phenolic Compounds from Geranium sanguineum by HPLC

Abstract

A high performance liquid chromatographic (HPLC) method has been developed for simultaneous determination of seventeen phenolic compounds (one phenolic acid, seven cinnamic acid derivatives, four quercetin glycosides, five flavonol, and flavone aglycones) from plant material. Separation of all examined compounds was carried out in 35 minutes on a Zorbax SB‐C₁₈ analytical column (100×3.0 mm, 3.5 µm) with methanol‐KH₂PO₄ buffer (40 mM, pH 2.3) as mobile phase in a linear gradient. The linearity of calibration curves for all compounds was very good (R2>0.999). The detection limits for the determined compounds were in the range of 18.4 to 91.9 ng/mL. The method was successfully applied for the determination of phenolic compounds from Geranium sanguineum dried herb, the following phenolic compounds being identified: caftaric acid (1.30 mg/g), caffeic acid (2.41 mg/g), hyperoside (1.64 mg/g), isoquercitrin (2.58 mg/g), rutin (1.71 mg/g), quercitrin (0.42 mg/g), quercetin (0.82 mg/g), kaempferol (0.19 mg/g). After acid hydrolysis treatment of the plant material, when all glycosides were hydrolyzed to aglycones, the type of unidentified flavonoids present in Geranium sanguineum were determined as being kaempferol glycosides.

Keywords:

• Column liquid‐chromatography
• Phenolic compounds
• Acid hydrolysis
• Geranium sanguineum
• Identification and quantification