Entity

Time filter

Source Type

Anji, China

Shi W.,Zhejiang University | Cheng Y.,Zhejiang University | Shao Y.,Skyherb Ingredients | Yan W.,Zhejiang University
Thermochimica Acta | Year: 2014

The solubilities of betulinic acid in binary solvent mixtures of THF + water in the temperature range of (278.2-318.2) K were determined by an analytical method. The solubility of betulinic acid in a binary solvent mixture increased with the increase of molar fraction of THF and the temperature. The solubilities data were correlated with a semi-empirical equation. The calculated solubilities showed good agreement with the experimental data. According to the Van't Hoff equation and the Gibbs equation, the thermodynamic properties for the solution process including Gibbs energy, enthalpy, and entropy were obtained. The crystal habit of betulinic acid changes in morphology at different solvent mixtures was observed using SEM. © 2014 Elsevier B.V. Source


Cheng Y.,Zhejiang University | Shao Y.,Skyherb Ingredients | Yan W.,Zhejiang University
Journal of Chemical and Engineering Data | Year: 2011

The solubilities of betulinic acid in methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 1-hexanol, ethyl formate, ethyl acetate, butyl acetate, acetone, and tetrahydrofuran were measured by an analytical method in the temperature range of (278.2 to 318.2) K. The experimental data were correlated with a three-parameter empirical equation and UNIQUAC model, respectively. The calculated solubilities showed good agreement with the experimental data over this temperature range. Furthermore, the relation of the solubilities and the crystal habit were discussed. © 2011 American Chemical Society. Source


Xiao M.,Zhejiang University | Shao Y.,Skyherb Ingredients | Yan W.,Zhejiang University | Zhang Z.,Zhejiang University
Journal of Chemical Thermodynamics | Year: 2011

The solubilities of apigenin and apigenin 7-O-rhamnosylglucoside in water, methanol, ethanol, 1-propanol, 1-butanol, acetone, and ethyl acetate from T = (288.2 to 328.2) K were measured. The solubilities of apigenin and apigenin 7-O-rhamnosylglucoside in selected solvents increase with increasing temperature, respectively. The experimental solubility data were correlated by a simplified thermodynamic equation and a three-parameter empirical equation. © 2010 Elsevier Ltd. All rights reserved. Source


Li B.,Zhejiang University | Li R.,Skyherb Ingredients | Yan W.,Zhejiang University
Journal of Chemical and Engineering Data | Year: 2011

The solubilities of phloretin in methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, pentan-1-ol, hexan-1-ol, ethyl acetate, butyl acetate, 1,4-dioxane, and water were measured at T = (288.2, 298.2, 308.2, 318.2, and 328.2) K and atmosphere pressure. The experimental results show that the phloretin is soluble in methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, pentan-1-ol, hexan-1-ol, ethyl acetate, butyl acetate, and 1,4-dioxane but insoluble in water. The solubilities of phloretin in selected solvents increase with increasing temperature. A simplified thermodynamic equation and a three-parameter Apelblat equation were used to correlate the experimental data. © 2011 American Chemical Society. Source


Li D.-W.,Zhejiang University | Zhu M.,Zhejiang Institute for Food and Drug Control | Shao Y.-D.,Skyherb Ingredients | Shen Z.,Zhejiang University | And 2 more authors.
Food Chemistry | Year: 2016

The quality of tea is mainly attributed to tea polyphenols and caffeine. In this paper, a new strategy for quality evaluation of green tea extracts was explored and verified through qualitative and quantitative analysis of multi-components by single marker (QAMS). Taguchi Design was introduced to evaluate the fluctuations of the relative conversion factors (fx) of tea catechins, gallic acid and caffeine to epigallocatechin gallate. The regression model (Sig. = 0.000) and the deviations (R2 > 0.999) between QAMS and normal external standard method proved the consistency of the two methods. Hierarchical cluster analysis and canonical discriminant analysis were employed to classify 26 batches of commercial Longjing green tea extracts (LJGTEs) collected from different producers. The results showed a significant difference in component profile between the samples from different origins. The QAMS method was verified to be an alternative and promising method to comprehensively and effectively control the quality of LJGTEs from different origins. © 2015 Elsevier Ltd. All rights reserved. Source

Discover hidden collaborations