HPLC ANALYSIS OF THE MAIN OXINDOLE ALKALOIDS FROM UNCARIA-TOMENTOSA

The main oxindole alkaloids from the root bark of Uncaria tomentosa were separated by reversed phase HPLC with an acetonitrile/methanol/phosphate buffer solvent gradient. UV detection was carried out at 245 nm. The chromatographic parameters for the separation of the alkaloids were optimized by studying the impact of the pH value of the mobile phase and the column temperature on the separation efficiency of the analytical system. The best separation was achieved with a mobile phase pH of 6.6 and a column temperature of 15-degrees-C. The method developed is suitable for the qualitative characterisation and quantitative determination of oxindole alkaloids in crude Uncaria tomentosa extracts and phytopharmaceuticals.