The stereochemistry of two 6, 9-oxygen bridge dibenzocyclooctadiene lignans from Kadsura coccinea, are difficult to separate and very unstable. The present study was designed to develop a high-performance liquid chrom...The stereochemistry of two 6, 9-oxygen bridge dibenzocyclooctadiene lignans from Kadsura coccinea, are difficult to separate and very unstable. The present study was designed to develop a high-performance liquid chromatography using circular dichroism detection for the analysis of the stereochemistry. A new 6, 9-oxygen bridge dibenzocyclooctadiene lignans named Kadsulignan Q was firstly found with an S-biphenyl configuration. The other compound was identified as Kadsulignan L with an R- biphenyl configuration. In order to obtain kinetic data on their reversible interconversion, the stability was measured at different deuterated solvents such as deuterated methanol, deuterated chloroform and deuterated dimethylsulfoxide. The lignans were more unstable and converted more easily in deuterated methanol than in deuterated chloroform and deuterated dimethylsulfoxide.展开更多
The present study was designed to establish and optimize a new method for extracting chlorogenic acid and cynaroside from Lonicera japonica Thunb. through orthogonal experimental designl. A new ultrahigh pressure extr...The present study was designed to establish and optimize a new method for extracting chlorogenic acid and cynaroside from Lonicera japonica Thunb. through orthogonal experimental designl. A new ultrahigh pressure extraction （UPE） technology was applied to extract chlorogenic acid and cynaroside from L. japonica. The influential factors, including solvent type, ethanol concentration, extraction pressure, time, and temperature, and the solid/liquid ratio, have been studied to optimize the extraction process, The optimal conditions for the UPE were developed by quantitative analysis of the extraction products by HPLC-DAD in comparison with standard samples. In addition, the microstructures of the medicinal materials before and after extraction were studied by scanning electron microscopy （SEM）. Furthermore, the extraction efficiency of different extraction methods and the 2, 2-diphenyl-1-picrylhydrazyl （DPPH） radical scavenging activities of the extracts were investigated. The optimal conditions for extracting chlorogenic acid and cynaroside were as follows： ethanol concentration, 60%; extraction pressure, 400 MPa; extraction time, 2 rain; extraction temperature, 30 ℃; and the solid/liquid ratio, 1 ： 50. Under these conditions, the yields of chlorogenic acid and cynaroside were raised to 4.863% and 0.080%, respectively. Compared with other extraction methods, such as heat reflux extraction （HRE）, ultrasonic extraction （UE）, and Sohxlet extraction （SE）, the UPE method showed several advantages, including higher extraction yield, shorter extraction time, lower energy consumption, and higher purity of the extracts. This study could help better utilize L. japonica flower buds as a readily accessible source of natural antioxidants in food and pharmaceutical industries.展开更多
基金supported by the PAPD(Priority Academic Program Development)of Jiangsu Higher Education Institutions,University Science Research Project of Jiangsu Province(No.09KJB350002)National Key Technology R&D Program(No.2012BAI30B02),National Natural Science Foundation of China(No.30901853)Hepatic Fibrosis Innovative Medicine-Research and Development of Fructus Schisandrae capsule(No.F12-157-9-00)
文摘The stereochemistry of two 6, 9-oxygen bridge dibenzocyclooctadiene lignans from Kadsura coccinea, are difficult to separate and very unstable. The present study was designed to develop a high-performance liquid chromatography using circular dichroism detection for the analysis of the stereochemistry. A new 6, 9-oxygen bridge dibenzocyclooctadiene lignans named Kadsulignan Q was firstly found with an S-biphenyl configuration. The other compound was identified as Kadsulignan L with an R- biphenyl configuration. In order to obtain kinetic data on their reversible interconversion, the stability was measured at different deuterated solvents such as deuterated methanol, deuterated chloroform and deuterated dimethylsulfoxide. The lignans were more unstable and converted more easily in deuterated methanol than in deuterated chloroform and deuterated dimethylsulfoxide.
基金supported by the PAPD(A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions)
文摘The present study was designed to establish and optimize a new method for extracting chlorogenic acid and cynaroside from Lonicera japonica Thunb. through orthogonal experimental designl. A new ultrahigh pressure extraction （UPE） technology was applied to extract chlorogenic acid and cynaroside from L. japonica. The influential factors, including solvent type, ethanol concentration, extraction pressure, time, and temperature, and the solid/liquid ratio, have been studied to optimize the extraction process, The optimal conditions for the UPE were developed by quantitative analysis of the extraction products by HPLC-DAD in comparison with standard samples. In addition, the microstructures of the medicinal materials before and after extraction were studied by scanning electron microscopy （SEM）. Furthermore, the extraction efficiency of different extraction methods and the 2, 2-diphenyl-1-picrylhydrazyl （DPPH） radical scavenging activities of the extracts were investigated. The optimal conditions for extracting chlorogenic acid and cynaroside were as follows： ethanol concentration, 60%; extraction pressure, 400 MPa; extraction time, 2 rain; extraction temperature, 30 ℃; and the solid/liquid ratio, 1 ： 50. Under these conditions, the yields of chlorogenic acid and cynaroside were raised to 4.863% and 0.080%, respectively. Compared with other extraction methods, such as heat reflux extraction （HRE）, ultrasonic extraction （UE）, and Sohxlet extraction （SE）, the UPE method showed several advantages, including higher extraction yield, shorter extraction time, lower energy consumption, and higher purity of the extracts. This study could help better utilize L. japonica flower buds as a readily accessible source of natural antioxidants in food and pharmaceutical industries.
