Abstract: Aim A capillary zone electrophoretic method (CZE) was used to determine the interactions between natural products and thrombin. Methods Samples containing natural products and thrombin at various ratios were incubated at 25 ℃ and then were separated by CZE with Tris-acetate buffer at pH 7.2. Each run could be accomplished within 5 min. Results In CZE, the peak width broadened due to the affinity interaction between natural products and thrombin. Compared with positive and negative control, the natural products (CB-1, CB-2) from Coreopsis tinctoria Nuttt. interacted with thrombin; CB-3 from Coreopsis tinctoria Nuttt. and HC-1, HC-2, HC-3 from Cistanche deserticola Ma. did not bind to thrombin. Both qualification and quantification characterizations of the binding were determined. Conclusion The established method is capable of sensitive and fast determination of natural products and thrombin interactions, it can be employed as an alternative method.

Key words: capillary zone electrophoresis, capillary zone electrophoresis, Coreopsis tinctoria Nuttt., Coreopsis tinctoria Nuttt., Cistanche deserticola Ma, Cistanche deserticola Ma, interactions, interactions, thrombin, thrombin