HPLC法测定冬凌草甲素的平衡溶解度和表观油水分配系数

Determination of equilibrium solubility of oridonin and its apparent oil/water partition coefficient by HPLC

目的测定冬凌草甲素在各种溶剂中的平衡溶解度以及在正辛醇-水和正辛醇-缓冲液体系中的表观油水分配系数。方法采用HPLC法测定冬凌草甲素的浓度,采用摇瓶法测定冬凌草甲素的表观油水分配系数。结果25℃冬凌草甲素在水中的平衡溶解度为0.75 g.L-1,在碱性磷酸盐缓冲液中的平衡溶解度更低;在常用的油中的溶解度小于1 g.L-1;冬凌草甲素的表观油水分配系数Papp为45.8(lgPapp=1.66)。结论冬凌草甲素的水溶性和脂溶性都较差,并且具有中等的疏水性。

Objective To determine the equilibrium solubility of oridonin in various media and its partition coefficients for the n-octanol-water/buffer solution systems. Methods A high performance liquid chromatography was established and used to detect the concentration of oridonin; the partition coefficients for the n-octanol-water/buffer solution systems of oridonin were determined by shaking flask method. Results The equilibrium solubility of oridonin in water was 0.75 g· L^-1 at 25 ℃ and had lower values in basic buffer solutions; lgPapp of oridonin was 1.66. Conclusions Oridonin is not soluble in either aqueous media or organic phase, its hydrophobicity is moderate.