Research on equilibrium solubility and apparent oil/water partition coefficient of flavonoids components in hawthorn leaves by similarity analysis / 中草药

ABSTRACT

Objective To study the equilibrium solubility and oil/water partition coefficient of Hawthorn leaves flavonoids (HLF) components, and compare their similarity, to lay the foundation for the characterization of the overall water soluble and fat soluble HLF components. Methods Taking HLF components as model drug, rutin, quercetin, and hyperin as representative components. The HPLC method was used to determine the equilibrium solubility and apparent oil/water distribution coefficient (Papp) of the components at different pH values and water. The similarity was evaluated by the vector cosine method (cosines) and Grubbs method (Grubbs). Chromatographic conditions The chromatographic column was Zorbax Eclipse Plus C18 column (250 mm × 4.6 mm, 5 μm), and the flow phase was acetonitrile (A) - 0.4% phosphate solution (B). The gradient elution program was 0—10 min (80% B), 10—11 min (80%—60% B), 11—20 min (60% B), 20—21 min (60%—80% B), and 21—25 min (80% B); The detection wavelength was 360 nm; The volume flow was 0.8 mL/min; The column temperature was 40 ℃. Results The equilibrium solubility and Papp of rutin, quercetin, hyperin were similar in different pH buffer solution and water. The solubility value of lutin, quercetin, and hyperoside in thebuffer solution of different pH were 0.998, 0.988, and 0.987, respectively. The cosine value of the apparent oil-water distribution coefficient was 0.976, 0.981, and 0.978, respectively. The cosine value was greater than 0.9. The Grubbs value of equilibrium solubility of lutin, quercetin and hyperoside were 1.057, 1.083, 1.124, 1.117, 1.022, 1.030, 1.082, and 1.112, respectively. The Grubbs values of the apparent oil-water distribution coefficient were 1.125, 1.107, 1.079, 1.034, 1.041, 1.037, 1.129, and 1.128. The results of Grubbs were less than G critical value of 1.153, and the similarity was good. Conclusion The similarity analysis reflects that the degree of dispersion of components objectively, which could increase the science of components evaluation and provide the basis for the formulation design of components of traditional Chinese medicine.