Abstract:

Following the principle and method on the measurement of oil-water partition coefficients by microemulsion electrokinetic chromatography (MEEKC), a traditional Chinese medicine fingerprint (TCM-FP) was established. The components which were extracted from the TCM were separated from each other by MEEKC under optimized operation conditions. The conditions of running solution were of 70 mmol/L SDS, 87 mmol/L n-heptane, 814 mmol/L n-butanol and 5 mmol/L sodium tetraborate with pH value of 8.80. The uncoated fused silica capillary used was 54 cm×75 μm with an effective length of 45 cm. The UV detection was carried out at 210 nm and an electrophoretic voltage of 15 kV was applied. SPSS program was used for the nonlinear regression of migration time and log Pow values of the standard compounds from literature, and the reliability of the established method has been investigated. As a result, the standard equation of regression with good linearity (r=0.9880) was obtained. The log Pow values of compounds measured under the same operation conditions were well consistent with those from literature. This method was applied to L. lucidum in which oleanolic acid is a main effective component. Besides the establishment of its TCM-FP, the log Pow of oleanolic acid, 3.63, was also obtained. The functional fingerprint of traditional Chinese medicine can give the log Pow of the extracts from TCM, reflect oil-water partition character of the constituents, and is of great significance to the selection of solvents, the design of dosage form, and the improvement of production technology.

Key words: L. lucidum , microemulsion electrokinetic chromatography (MEEKC), oil-water partition coefficients, traditional Chinese medicine fingerprint (TCM-FP)