Simultaneous determination of five nucleosides and nucleobases of Rehmannia glutinosa Libosch. by high performance liquid chromatography

This study is to establish a method for simultaneously determination of five nucleosides and nucleobases, including hypoxanthine, uridine, adenine, guanosine and adenosine in Rehmannia glutinosa Libosch. which was collected from different regions in China.  A Diamonsil C₁₈ column (250 mm × 4.6 mm, 5 μm) was used.  Acetonitrile and 0.04 mol·L⁻¹ potassium dihydrogen phosphate solution were adopted as mobile phase with gradient elution.  The flow rate was 1 mL·min⁻¹ and column temperature was 30 ℃.  The detection wavelength was at 254 nm.  The method had good linearity over the range of 1.0 − 16.0 μg·mL⁻¹ (r² = 0.999 8), 5.0 − 80.0 μg·mL⁻¹ (r² = 0.999 8), 1.0 − 16.0 μg·mL⁻¹ (r² = 0.999 5), 1.25 − 20.0 μg·mL⁻¹ (r² = 0.999 8) and 1.0 − 16.0 μg·mL⁻¹ (r² = 0.999 8) for hypoxanthine, uridine, adenine, guanosine and adenosine, respectively.  The average recoveries were between 98.8% and 100.7%.  The content of hypoxanthine, uridine, adenine, guanosine and adenosine in Rehmannia glutinosa Libosch. from different regions was significantly different.  This established method was sensitive and reliable for the quantification of five chemical constituents in Rehmannia glutinosa Libosch.