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.
ABSTRACT
Objective To compare the Cosine and Dip methods in describing the rhythm of blood pressure(BP).Methods The BP was measured with non-traumatic ambulatory blood pressure monitoring(ABPM) for 24 h and analyzed with Cosine and Dip methods.The characters of the circadian rhythm of BP were studied and two methods were compared.Results The ratios of mesor and amplitude(A/M) of systolic blood pressure(SBP) and diastolic blood pressure(DBP) were(7.78?0.42)% and(7.98?0.39)%,respectively.The majority of acrophases of BP was on daytime,especially between 10∶00 am and 3∶00 pm.The amplitudes of acrophase in different periods analyzed with Cosine method were not significantly different each other,whereas analyzed with Dip method to be significant difference.Conclusion There is difference between Cosine and Dip methods in describing the rhythm of BP,since rhythms of acrophases of some cases were inaccurately described with Dip method.