RESUMO
OBJECTIVE：To establish a method for the determination of plasma protein binding rate of rosmarinic acid ，caffeic acid and chlorogenic acid from Glechoma longituba . METHODS ：UHPLC method combined with ultrafiltration method was adopted to determine the plasma protein binding rate of rosmarinic acid ，caffeic acid and chlorogenic acid from G. longituba in the plasma of New Zealand rabbits. The determination was performed on a Phenomenex Luna ® C18 column with mobile phase consisted of acetonitrile （A）-0.1％ formic acid solution （B）（gradient elution ）at the flow rate of 0.5 mL/min. The column temperature was set at 45 ℃，and the detection wavelength was 327 nm. The sample size was 3 μL. RESULTS：At low ，medium and high concentrations，the plasma binding rates of rosmarinic acid were （97.78 ± 1.67）％ ，（94.32 ± 1.42）％ ，（95.12 ± 1.51）％ ， respectively（n＝3）；those of caffeic acid were （90.12±2.33）％，（89.53±1.98）％，（90.23±1.56）％，respectively（n＝3）；those of chlorogenic acid were （63.23 ± 2.12）％ ，（67.87 ± 1.06）％ ，（62.34 ± 1.34）％ ，respectively （n＝3）. CONCLUSIONS ： Established method is easy to operate and shorter time for analysis. It can be used to determine the plasma protein binding rate of rosmarinic acid ，caffeic acid and chlorogenic acid in G. longituba .