The isolation of minor components from complex natural product matrices presents a significant challenge in the field of purification science due to their low concentrations and the presence of structurally similar co...The isolation of minor components from complex natural product matrices presents a significant challenge in the field of purification science due to their low concentrations and the presence of structurally similar compounds.This study introduces an optimized twin-column recycling chromatography method for the efficient and simultaneous purification of these elusive constituents.By introducing water at a small flowing rate between the twin columns,a step solvent gradient is created,by which the leading edge of concentration band would migrate at a slower rate than the trailing edge as it flowing from the upstream to downstream column.Hence,the band broadening is counterbalanced,resulting in an enrichment effect for those minor components in separation process.Herein,two target substances,which showed similar peak position in high performance liquid chromatography(HPLC)and did not exceed 1.8%in crude paclitaxel were selected as target compounds for separation.By using the twin-column recycling chromatography with a step solvent gradient,a successful purification was achieved in getting the two with the purity almost 100%.We suggest this method is suitable for the separation of most components in natural produces,which shows higher precision and recovery rate compared with the common lab-operated separation ways for natural products(thin-layer chromatography and prep-HPLC).展开更多
The low temperature coal tar(CT)is taken as the raw material,and the extraction and column chromatography are used for detailed and accurate characterization in this paper.The n-heptane soluble fraction(CT-HS)and inso...The low temperature coal tar(CT)is taken as the raw material,and the extraction and column chromatography are used for detailed and accurate characterization in this paper.The n-heptane soluble fraction(CT-HS)and insoluble fraction(CT-HI)were obtained by n-heptane Soxhlet extraction.The extraction rate of CT-HS reached 92.79%(mass),which indicated that there are few heavy compounds in it.Further,different solvents(methylbenzene,benzene,ethyl acetate,methylbenzene-ethanol)were used to elute CT-HS by chromatographic column to obtain five fractions(saturates,aromatics,heteroatoms,phenolics and resins,named CT-SA,CT-AR,CT-HE,CT-PH,CT-RE,respectively).The yields of CTSA,CT-AR,CT-HE,CT-PH,CT-RE are 42.12%,10.43%,2.19%,9.50%and 6.63%(mass),respectively.Gas chromatography-mass spectrometry analysis of eluting components show that alkanes are the main components in CT,followed by polycyclic aromatics,and the corresponding fractions are CT-SA and CT-AR,respectively.The relative content of aliphatics in CT-SA is 76.93%,and the relative content of aromatics in CT-AR is 75.05%.This separation technology effectively separates and enriches different components in CT,and the activation energy required for the pyrolysis process of a single eluting fraction is lower than that of CT,which is expected to provide an important reference for the separation,analysis and conversion of complex oil products such as coal-oil co-processing products,coal tar and other complex heavy carbon oil products.展开更多
基金supported by the National Natural Science Foundation of China(22078281)。
文摘The isolation of minor components from complex natural product matrices presents a significant challenge in the field of purification science due to their low concentrations and the presence of structurally similar compounds.This study introduces an optimized twin-column recycling chromatography method for the efficient and simultaneous purification of these elusive constituents.By introducing water at a small flowing rate between the twin columns,a step solvent gradient is created,by which the leading edge of concentration band would migrate at a slower rate than the trailing edge as it flowing from the upstream to downstream column.Hence,the band broadening is counterbalanced,resulting in an enrichment effect for those minor components in separation process.Herein,two target substances,which showed similar peak position in high performance liquid chromatography(HPLC)and did not exceed 1.8%in crude paclitaxel were selected as target compounds for separation.By using the twin-column recycling chromatography with a step solvent gradient,a successful purification was achieved in getting the two with the purity almost 100%.We suggest this method is suitable for the separation of most components in natural produces,which shows higher precision and recovery rate compared with the common lab-operated separation ways for natural products(thin-layer chromatography and prep-HPLC).
基金financed by the project supported by the National Natural Science Foundation of China(22078266,21908180,22178289,22278338)the Key Research and Development Program of Shaanxi(2020ZDLGY11-02,2021GY-136)the Special Fund for High-level Scholars of China(XJ21B10)。
文摘The low temperature coal tar(CT)is taken as the raw material,and the extraction and column chromatography are used for detailed and accurate characterization in this paper.The n-heptane soluble fraction(CT-HS)and insoluble fraction(CT-HI)were obtained by n-heptane Soxhlet extraction.The extraction rate of CT-HS reached 92.79%(mass),which indicated that there are few heavy compounds in it.Further,different solvents(methylbenzene,benzene,ethyl acetate,methylbenzene-ethanol)were used to elute CT-HS by chromatographic column to obtain five fractions(saturates,aromatics,heteroatoms,phenolics and resins,named CT-SA,CT-AR,CT-HE,CT-PH,CT-RE,respectively).The yields of CTSA,CT-AR,CT-HE,CT-PH,CT-RE are 42.12%,10.43%,2.19%,9.50%and 6.63%(mass),respectively.Gas chromatography-mass spectrometry analysis of eluting components show that alkanes are the main components in CT,followed by polycyclic aromatics,and the corresponding fractions are CT-SA and CT-AR,respectively.The relative content of aliphatics in CT-SA is 76.93%,and the relative content of aromatics in CT-AR is 75.05%.This separation technology effectively separates and enriches different components in CT,and the activation energy required for the pyrolysis process of a single eluting fraction is lower than that of CT,which is expected to provide an important reference for the separation,analysis and conversion of complex oil products such as coal-oil co-processing products,coal tar and other complex heavy carbon oil products.
