[Objectives]To study the chemical constituents of the fruit of Embelia undulata(Wall.)Mez.[Methods]Silica gel column chromatography,gel column chromatography,recrystallization,high-performance preparative liquid chrom...[Objectives]To study the chemical constituents of the fruit of Embelia undulata(Wall.)Mez.[Methods]Silica gel column chromatography,gel column chromatography,recrystallization,high-performance preparative liquid chromatography and other modern separation methods and techniques were used to separate and purify the chemical components of the ethyl acetate fraction of the fruit of E.undulata(Wall.)Mez,and based on the physical and chemical properties and spectral data,their structure was identified.[Results]Six compounds were isolated from the fruit of E.undulata(Wall.)Mez,including trimethyl citrate(1),vanillic acid(2),5-hydroxymethylfurfural(3),1,5-dimethyl citrate(4),1,6-dimethyl-5-ethyl citrate(5)and 3,4-dihydroxybenzoic acid(6).[Conclusions]Compounds 1-6 are all isolated from E.undulata(Wall.)Mez for the first time.展开更多
To investigate the enthalpy relaxation behavior of maltitol glass system,differential scanning calorimetry（DSC） was used to obtain the specific heat capacity[C p（T）] near the glass transition temperature（T g） at...To investigate the enthalpy relaxation behavior of maltitol glass system,differential scanning calorimetry（DSC） was used to obtain the specific heat capacity[C p（T）] near the glass transition temperature（T g） at different cooling rates ranged between 1 and 20 K/min.Three phenomenological models of enthalpy relaxation,ToolNarayanaswamy-Moynihan（TNM） model,Adam-Gibbs-Vogel（AGV） model and Gómez Ribelles（GR） model,were used to simulate the experimental data.The models＇ parameters were obtained via a curve-fitting method.The results indicate that TNM and AGV models gave the almost identical prediction powers and can reproduce the curves of experimental C p（T） very well.However,the prediction power of GR model evolved from configurational entropy approach is not so good as those of TNM and AGV models.In particular,the metastable limit state parameter（δ） introduced by Gómez Ribelles has insignificant effect on the enthalpy relaxation of the small molecular hydrogen-bonding glass system.展开更多
[Objectives]The research aimed to study the characteristics of Ardisia gigantifolia and its adulterants Embelia scandens and Mappianthus iodoides for identification. [Methods] Through the trait identification method,p...[Objectives]The research aimed to study the characteristics of Ardisia gigantifolia and its adulterants Embelia scandens and Mappianthus iodoides for identification. [Methods] Through the trait identification method,powder microscopic identification method,TLC,inclusions detection and content determination,A. gigantifolia and its adulterants were contrasted. [Results]The morphological and histological characteristics of A. gigantifolia,E. scandens and M. iodoides were different from each other. Containing water,total ash,acid insoluble ash and other inclusions also had difference; the total triterpenoid saponins were respectively 122. 90 mg/g of A. gigantifolia,147. 052 mg/g of E. scandens,and 63. 06 mg/g of M. iodoides. [Conclusions] These methods are accurate and reliable,which could be used for the identification of A. gigantifolia and its adulterants.展开更多
基金Independent Research Project of Guangxi Key Laboratory of Traditional Chinese Medicine Quality Standards(Gui Zhong Zhong Zi 201503).
文摘[Objectives]To study the chemical constituents of the fruit of Embelia undulata(Wall.)Mez.[Methods]Silica gel column chromatography,gel column chromatography,recrystallization,high-performance preparative liquid chromatography and other modern separation methods and techniques were used to separate and purify the chemical components of the ethyl acetate fraction of the fruit of E.undulata(Wall.)Mez,and based on the physical and chemical properties and spectral data,their structure was identified.[Results]Six compounds were isolated from the fruit of E.undulata(Wall.)Mez,including trimethyl citrate(1),vanillic acid(2),5-hydroxymethylfurfural(3),1,5-dimethyl citrate(4),1,6-dimethyl-5-ethyl citrate(5)and 3,4-dihydroxybenzoic acid(6).[Conclusions]Compounds 1-6 are all isolated from E.undulata(Wall.)Mez for the first time.
基金Supported by the National Natural Science Foundation of China(No.20803016)the Natural Science Foundation of Anhui Province,China(No.070414163)
文摘To investigate the enthalpy relaxation behavior of maltitol glass system,differential scanning calorimetry（DSC） was used to obtain the specific heat capacity[C p（T）] near the glass transition temperature（T g） at different cooling rates ranged between 1 and 20 K/min.Three phenomenological models of enthalpy relaxation,ToolNarayanaswamy-Moynihan（TNM） model,Adam-Gibbs-Vogel（AGV） model and Gómez Ribelles（GR） model,were used to simulate the experimental data.The models＇ parameters were obtained via a curve-fitting method.The results indicate that TNM and AGV models gave the almost identical prediction powers and can reproduce the curves of experimental C p（T） very well.However,the prediction power of GR model evolved from configurational entropy approach is not so good as those of TNM and AGV models.In particular,the metastable limit state parameter（δ） introduced by Gómez Ribelles has insignificant effect on the enthalpy relaxation of the small molecular hydrogen-bonding glass system.
基金Supported by Scientific Research Program of Guangdong Provincial Administration of Traditional Chinese Medicine(20171282)Zhongshan Science and Technology Plan Project(2017B1094)
文摘[Objectives]The research aimed to study the characteristics of Ardisia gigantifolia and its adulterants Embelia scandens and Mappianthus iodoides for identification. [Methods] Through the trait identification method,powder microscopic identification method,TLC,inclusions detection and content determination,A. gigantifolia and its adulterants were contrasted. [Results]The morphological and histological characteristics of A. gigantifolia,E. scandens and M. iodoides were different from each other. Containing water,total ash,acid insoluble ash and other inclusions also had difference; the total triterpenoid saponins were respectively 122. 90 mg/g of A. gigantifolia,147. 052 mg/g of E. scandens,and 63. 06 mg/g of M. iodoides. [Conclusions] These methods are accurate and reliable,which could be used for the identification of A. gigantifolia and its adulterants.
