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
Deoxynivalenol(DON) is a type B trichothecenes mycotoxin produced by several Fusarium species, often found in foodstuffs for humans and animals. DON is in great demand for the toxicological researches both in vivo a...Deoxynivalenol(DON) is a type B trichothecenes mycotoxin produced by several Fusarium species, often found in foodstuffs for humans and animals. DON is in great demand for the toxicological researches both in vivo and in vitro. In this work, wheat culture was inoculated with a Fusarium graminearum PH-1 strain for DON production. The solvent system for crude extraction was acetonitrile-water(84:16, v/v). A simple two-step silica gel column chromatography was employed to separate the DON mycotoxin from wheat culture, combined with preparative high performance liquid chromatography(preparative HPLC) to purify the compound. The solvent system for the second silica gel column chromatography was methylene chloride-methanol(17:1, v/v), which provided a good elution effect selected on thin layer chromatography(TLC). The target compound was identified by HPLC, and the chemical structure was confirmed by mass spectrometry(MS) and ~1H and ^(13)C nuclear magnetic resonance(NMR) spectroscopy. A total of 433 mg of purified DON was obtained from 1 kg of wheat culture, with a purity of 99.01%. The study had provided an easy-operating and cost-effective method to isolate an expensive compound in a simple way.展开更多
The liquefied product of Salixpsammophila wood was separated by thin-layer chromatography (TLC) and column chromatography, and its structure was identified by nuclear magnetic resonance (NMR) spectra in our study....The liquefied product of Salixpsammophila wood was separated by thin-layer chromatography (TLC) and column chromatography, and its structure was identified by nuclear magnetic resonance (NMR) spectra in our study. The separation result indicates that the sample of liquefied S. psammophila contained at least two categories of components. The structure of the main components was guaiacyl C-1, C-2 of the hydroxyphenyl propane, i.e., the aromatic nucleus protons of lignin. Degradation and polycondensation reactions occurred when the S. psammophila wood was liquefied in phenol. Polycondensation reactions occurred among the depolymerization products from cellulose, the aromatic depolymerization products from lignin and the products of the displacement reactions between phenoxide ion and cellulose.展开更多
Alkaloids have a variety of bioactivities and great development value in the fields of pharmaceuticals, cosmetics and health food. Column chromatography is a common method for preparing alkaloids. In this paper, the r...Alkaloids have a variety of bioactivities and great development value in the fields of pharmaceuticals, cosmetics and health food. Column chromatography is a common method for preparing alkaloids. In this paper, the research status of the separation and purification of alkaloids from Chinese medicines by column chromatography is reviewed, and the factors that influence the refining of alkaloids via a macroporous adsorption resin, ion exchange resin and silica gel are summarized. The thermodynamic and kinetic modeling methods for the static adsorption of adsorbents are also reviewed in this paper. It is suggested that the modeling method of the column chromatography process be deeply studied to establish a more stringent quality control method for sampling liquid and to strengthen the online detection of the chromatography process to improve the refining effect of alkaloids.展开更多
Syzygium jambolanum is a promising natural treatment for diabetes.The potential benefits of S jambolanum for diabetes include lowering blood sugar levels,increasing insulin sensitivity,protecting pancreatic beta cells...Syzygium jambolanum is a promising natural treatment for diabetes.The potential benefits of S jambolanum for diabetes include lowering blood sugar levels,increasing insulin sensitivity,protecting pancreatic beta cells,and slowing the absorption of glucose into the bloodstream.The anti-diabetic activity of the crude extract of S jambolanum was evaluated in L6 myotubes and the lipid deposition in tissue was measured using Nile red Staining.Nile red staining confirmed that a considerable quantity of lipids had been deposited in the tissue treated with a crude extract of S jambolanum,comparable to the quantity of lipids deposited with a standard drug known as Rosiglitazone.This study analyzed the anti-diabetic activity of a crude extract of S jambolanum to understand its potential as a feedstock for extracting bioactive constituents to screen for bioactive molecules in the treatment of diabetes.展开更多
The thermal behaviors of five proteins in hydrophobic interaction chromatography (HIC) were investigated in the temperature range from 0 to 50℃. The thermodynamic parameters (△H°,△S°, △Cp°and △G...The thermal behaviors of five proteins in hydrophobic interaction chromatography (HIC) were investigated in the temperature range from 0 to 50℃. The thermodynamic parameters (△H°,△S°, △Cp°and △G°) of these proteins in the process of retention and unfolding were determined. The existence of enthalpy and entropy convergence with temperature was confirmed. The differences of the isoentropic and isoenthalpic temperatures for protein unfolding in HIC system from the traditional solution were elucidated.展开更多
Resveratrol is a dietary polyphenol espoused to have chemopreventive activity against a variety of human cancer types. We first reported that resveratrol significantly decreases the proliferation of both androgen-depe...Resveratrol is a dietary polyphenol espoused to have chemopreventive activity against a variety of human cancer types. We first reported that resveratrol significantly decreases the proliferation of both androgen-dependent and hormone-refractory prostate cancer cells. However, the effects of resveratrol in normal prostate epithelial and stromal cells, particularly with regard to its uptake, subcellular distribution and intracellular targets, have not been investigated. To advance the knowledge on accessibility and cellular disposition of resveratrol in prostate cells, [3H] resveratrol, fractionation of cell extracts into subcellular compartments, Western blot analysis, resveratrol affinity column chromatography and flow cytometry were used to study the uptake and intracellular distribution of resveratrol in normally cultured prostate stromal (PrSCs) and epithelial cells (PrECs). Pretreatment of both PrSCs and PrECs for 2 days with resveratrol modulated its uptake and selectively increased its distribution to the membrane and organelle compartments. Resveratrol affinity column chromatography studies showed differential expression of a previously identified resveratrol-targeting protein, quinone reductase 2 (QR2), in PrSCs and PrECs. Flow cytometric analysis comparing resveratrol-treated and untreated PrSCs showed a large decrease in G1-phase and a concomitant increase in S and G2/M-phases of the cell cycle. These results suggest that resveratrol suppresses PrSC proliferation by affecting cell cycle phase distribution, which may involve the participation by QR2.展开更多
Glycerol dialkyl glycerol tetraethers(GDGTs), specific membrane lipids synthesized mainly by bacteria and archaea, can be divided into isoprenoids and methyl branched alkyl GDGTs(i GDGTs and brGDGTs, respectively). Th...Glycerol dialkyl glycerol tetraethers(GDGTs), specific membrane lipids synthesized mainly by bacteria and archaea, can be divided into isoprenoids and methyl branched alkyl GDGTs(i GDGTs and brGDGTs, respectively). Three GDGTs groups(i GDGTs, brGDGTs, and other membrane lipids) in a peat sample were separated and collected in this study using semi-preparative high-performance liquid chromatography(HPLC) and silica gel column chromatography. The obtained recoveries for the whole analytical procedure were 85% – 55% using semi-preparative HPLC and 70% – 20% using gel column chromatography. In addition, in each method, the recoveries of brGDGTs and iGDGTs were similar, regardless of the huge difference in their contents. High purity was found in the fractionated groups, determined based on ether cleavage and reduction. Moreover, the semi-preparative HPLC method could realize a better separation efficiency than the silica gel method, but it was time-consuming and required expensive equipment, while the silica gel chromatography method featured merits of time saving and convenient operation at the cost of a slight reduction in separation efficiency. The advantages of the silica gel method make it an operational laboratory method for batch experiments and isotopic studies.展开更多
Nicotine is an alkaloid mainly found in leaves of tobacco and is used therapeutically for patients seeking relief from tobacco dependence in the form of products such as gums, patches, lozenges etc. In these products,...Nicotine is an alkaloid mainly found in leaves of tobacco and is used therapeutically for patients seeking relief from tobacco dependence in the form of products such as gums, patches, lozenges etc. In these products, majorly nicotine derived from tobacco is used which is inherently contaminated with undesirable nicotine related substances as impurities at low levels and is difficult to remove. Hence, use of synthetic nicotine is considered as an option which will be devoid of such impurities. In this work, a short and efficient synthesis of (R) and (S) nicotine was achieved by leveraging a key esterification between racemic homoallylic alcohol intermediate (2) and (S)-Ibuprofen (3) to produce diastereomers (5a) and (5b) which were easily separable under standard column chromatography conditions. Use of (S)-Ibuprofen (3) as a chiral resolving agent constitutes a novel approach which was not reported earlier. A subsequent hydrolysis of the diastereomers furnished the homoallylic alcohol intermediates (S)-6a and (R)-6a with high enantiopurity, which was effectively translated to the corresponding (R)-nicotine and (S)-nicotine respectively.展开更多
A simple, reliable and accurate high performance liquid chromatography(HPLC) coupled with a UV detector at varied wavelength was developed for the quantitation of two types of anti-carcinogenic compounds, namely, Kush...A simple, reliable and accurate high performance liquid chromatography(HPLC) coupled with a UV detector at varied wavelength was developed for the quantitation of two types of anti-carcinogenic compounds, namely, Kushen alkaloids(KS-As) and Kushen flavonoids(KS-Fs), in Kushen. Their remarkable difference in physicochemical properties was circumvented by integrated optimization of column and mobile phase. The separation was achieved on an alkaline-resisting C18 column via gradient elution with acetonitrile(ACN) and 0.025%(volume ratio) diethylamine(DEA) in water as mobile phase. The flow rate was 0.7 mL/min, and the column temperature was maintained at 35 °C. UV detection wavelength was set at 225 nm to monitor KS-As, and then changed to 335 nm for KS-Fs at 26th min, which was kept for 30 min before returning to the original wavelength. All the calibration curves show good linearity(r20.999) within test ranges. The intra- and inter-day precision values of these components were less than 3.82%, and the average recovery rates obtained were in a range of 97.24%―102.64% for all the samples with RSD below 3.94%. This assay was successfully applied to determining the major active components in commercial herbal samples of Kushen. Moreover, the possible relationship between sample and the geographical region was visualized based on the contents of the 6 compounds in the light of principal component analysis(PCA). The results suggest that the proposed method facilitates the quality control of Kushen.展开更多
A simple,rapid and sensitive method for the quantification of camellianin B in Cephalotaxus sinensis(C.sinensis)a natural plant with anti-hyperglycemic effect,was developed and validated by reversed phase liquid chr...A simple,rapid and sensitive method for the quantification of camellianin B in Cephalotaxus sinensis(C.sinensis)a natural plant with anti-hyperglycemic effect,was developed and validated by reversed phase liquid chromatography.Chromatographic separation was achieved on a C18 column and an isocratic elution was carried out at a flow-rate of 1.0 mL·min-1 with the acetonitrile-water containing0.1%formic acid(19∶81,v/v).The detection wavelength was set at 330 nm.The calibration curve was linear over the concentration range of 0.25-50μg·mL-1 with correlation coefficients larger than0.999 5.The limit of detection and limit of quantification were 0.09μg·mL-1and 0.25μg·mL-1,respectively.The precisions and accuracy for all samples were acceptable.The validated method has been successfully applied for the quantification of camellianin B in C.sinensis harvested in different months and may also be used as the quality evaluation of this herb medicine.展开更多
This article deals with extraction and purification of deguelin,which is a main rotenoid occurred in the root of Derris trifoliate Lour.Deguelin has gained much attention of scientists because of its potential ability...This article deals with extraction and purification of deguelin,which is a main rotenoid occurred in the root of Derris trifoliate Lour.Deguelin has gained much attention of scientists because of its potential ability to inhibit cancer cell proliferation.The dried root powder was extracted with ethanol by ultrasonic-assisted extraction for 30 min,and then filtrated and concentrated to give pasty concentrate.The concentrate was loaded onto silica gel column chromatography subsequently;and the chemical was eluted using a binary solvent mixture of petroleum ether(60-90ºC)-ethyl acetate(4:1,v/v).All tentative identification was carried out by high performance liquid chromatography(HPLC).Most crystal of deguelin was obtained after the fractions mainly containing deguelin were pooled and placed in the dark at 4ºC for three days.With recrystallization from carbon tetrachloride for three times,the purity of deguelin crystal was 99.15%and the yield was 0.55%of the dried weight of D.trifoliate Lour root.展开更多
The influencing factors of extracellular polysac-charide(EPS)produced from a strain of lactic acid bacteria(LAB L15)were studied by using the phenol-H2SO4 method.It was demonstrated that the strain produced EPS at the...The influencing factors of extracellular polysac-charide(EPS)produced from a strain of lactic acid bacteria(LAB L15)were studied by using the phenol-H2SO4 method.It was demonstrated that the strain produced EPS at the most amount when it was incubated for 40-48 h and when the pH value was 4 under 30℃.Glucose was the most suitable carbon source for LAB-producing EPS.The rough EPS was obtained from L15 culture after centrifugation,dialysis,deprotein,decoloration,and ethanol-precipitation.The sample was at least composed of two polysaccharides that were completely different in molecular weight and the amount.The purified EPS was passed through the SephadexG-200 column and it showed that it was a sample purified by thin layer chromatography.展开更多
Objective:To screen seaweed Sargassum wightii(S.wightii)for bioactive natural substance against marine ornamental fish bacterial pathogens,and also study the antioxidant properties,brine shrimp toxicity effect.Methods...Objective:To screen seaweed Sargassum wightii(S.wightii)for bioactive natural substance against marine ornamental fish bacterial pathogens,and also study the antioxidant properties,brine shrimp toxicity effect.Methods:Crude extract was made using three solvents(acetone,ethanol and methanol)and screened for antibacterial activity and purified by column chromatography,purified fractions obtained were tested for the activity.The 1st fraction of acetone extract showed maximum activity,this was again subjected for purification and obtained three sub-fractions also tested for the activity.Total phenols and flavonoid contents,reducing power,free radical scavenging activities(DPPH and H_(2)O_(2))and brine shrimp toxicity were also studied using purified acetone extract followed by standard methods.Results:The purified acetone extract showed maximum activity against eight pathogens among ten.GC-MS results revealed two major compounds such as 24-methylene cholesterol(79.9%)and methyl oleate(30.3%)which presented in higher percentage in purified extract and had highest phenols and flavonoid contents,reducing power,free radical scavenging activities,and also showed less toxicity effect.In he present study,the purified extract of S.wightii had potential antibacterial activity against Aeromonas hydrophila[(22.25±0.35)mm]and minimum activity against Streptococcus sp.[(10.00±0.00)mm].The purified extract of S.wightii also had potential total antioxidant activity of(3.87±0.04)μg at 100μg/mL concentration and the lowest activity was exhibited(1.52±0.01)μg at 25μg/mL.Conclusions:The present study concluded that the brown seaweed,S.wightii has potential antimicrobial and antioxidant activities,which can be used in aquaculture industry for treated bacterial diseases in infected fishes.展开更多
A reliable and accurate liquid chromatography with evaporative light scattering detection(LC-ELSD)method was developed for simultaneous determination of five constituents in Xue-Fu-Zhu-Yu capsule,a widely used prescri...A reliable and accurate liquid chromatography with evaporative light scattering detection(LC-ELSD)method was developed for simultaneous determination of five constituents in Xue-Fu-Zhu-Yu capsule,a widely used prescription of traditional Chinese medicine(TCM).The chromatographic separation was performed on a Symmetry C_(18)column(150 mm×4.6 mm,5.0μm)using gradient elution of acetonitrile and water(containing 1.0%acetic acid).The flow rate was 0.6 mL/min and the temperature of column was 30℃.A good linearity correlation was obtained over the investigated concentration ranges.Recoveries of the five components varied from 97.31%to 99.84%(RSD<4.0%).The validated method was successfully applied to the quality assessment of Xue-Fu-Zhu-Yu capsule.展开更多
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.
基金supported by the National Natural Science Foundation of China (31402268)the Natural Science Foundation of Jiangsu Province of China (BK20140691)+1 种基金Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), ChinaThe Introduction of International Advanced Agricultural Science and Technology Project from the Ministry of Agriculture of China (2012-Z22)
文摘Deoxynivalenol(DON) is a type B trichothecenes mycotoxin produced by several Fusarium species, often found in foodstuffs for humans and animals. DON is in great demand for the toxicological researches both in vivo and in vitro. In this work, wheat culture was inoculated with a Fusarium graminearum PH-1 strain for DON production. The solvent system for crude extraction was acetonitrile-water(84:16, v/v). A simple two-step silica gel column chromatography was employed to separate the DON mycotoxin from wheat culture, combined with preparative high performance liquid chromatography(preparative HPLC) to purify the compound. The solvent system for the second silica gel column chromatography was methylene chloride-methanol(17:1, v/v), which provided a good elution effect selected on thin layer chromatography(TLC). The target compound was identified by HPLC, and the chemical structure was confirmed by mass spectrometry(MS) and ~1H and ^(13)C nuclear magnetic resonance(NMR) spectroscopy. A total of 433 mg of purified DON was obtained from 1 kg of wheat culture, with a purity of 99.01%. The study had provided an easy-operating and cost-effective method to isolate an expensive compound in a simple way.
基金supported by grants 200508010603 and 200711020504 from the key pro-ject of the Natural Science Foundation of the InnerMongolia Autonomous Region
文摘The liquefied product of Salixpsammophila wood was separated by thin-layer chromatography (TLC) and column chromatography, and its structure was identified by nuclear magnetic resonance (NMR) spectra in our study. The separation result indicates that the sample of liquefied S. psammophila contained at least two categories of components. The structure of the main components was guaiacyl C-1, C-2 of the hydroxyphenyl propane, i.e., the aromatic nucleus protons of lignin. Degradation and polycondensation reactions occurred when the S. psammophila wood was liquefied in phenol. Polycondensation reactions occurred among the depolymerization products from cellulose, the aromatic depolymerization products from lignin and the products of the displacement reactions between phenoxide ion and cellulose.
文摘Alkaloids have a variety of bioactivities and great development value in the fields of pharmaceuticals, cosmetics and health food. Column chromatography is a common method for preparing alkaloids. In this paper, the research status of the separation and purification of alkaloids from Chinese medicines by column chromatography is reviewed, and the factors that influence the refining of alkaloids via a macroporous adsorption resin, ion exchange resin and silica gel are summarized. The thermodynamic and kinetic modeling methods for the static adsorption of adsorbents are also reviewed in this paper. It is suggested that the modeling method of the column chromatography process be deeply studied to establish a more stringent quality control method for sampling liquid and to strengthen the online detection of the chromatography process to improve the refining effect of alkaloids.
文摘Syzygium jambolanum is a promising natural treatment for diabetes.The potential benefits of S jambolanum for diabetes include lowering blood sugar levels,increasing insulin sensitivity,protecting pancreatic beta cells,and slowing the absorption of glucose into the bloodstream.The anti-diabetic activity of the crude extract of S jambolanum was evaluated in L6 myotubes and the lipid deposition in tissue was measured using Nile red Staining.Nile red staining confirmed that a considerable quantity of lipids had been deposited in the tissue treated with a crude extract of S jambolanum,comparable to the quantity of lipids deposited with a standard drug known as Rosiglitazone.This study analyzed the anti-diabetic activity of a crude extract of S jambolanum to understand its potential as a feedstock for extracting bioactive constituents to screen for bioactive molecules in the treatment of diabetes.
文摘The thermal behaviors of five proteins in hydrophobic interaction chromatography (HIC) were investigated in the temperature range from 0 to 50℃. The thermodynamic parameters (△H°,△S°, △Cp°and △G°) of these proteins in the process of retention and unfolding were determined. The existence of enthalpy and entropy convergence with temperature was confirmed. The differences of the isoentropic and isoenthalpic temperatures for protein unfolding in HIC system from the traditional solution were elucidated.
文摘Resveratrol is a dietary polyphenol espoused to have chemopreventive activity against a variety of human cancer types. We first reported that resveratrol significantly decreases the proliferation of both androgen-dependent and hormone-refractory prostate cancer cells. However, the effects of resveratrol in normal prostate epithelial and stromal cells, particularly with regard to its uptake, subcellular distribution and intracellular targets, have not been investigated. To advance the knowledge on accessibility and cellular disposition of resveratrol in prostate cells, [3H] resveratrol, fractionation of cell extracts into subcellular compartments, Western blot analysis, resveratrol affinity column chromatography and flow cytometry were used to study the uptake and intracellular distribution of resveratrol in normally cultured prostate stromal (PrSCs) and epithelial cells (PrECs). Pretreatment of both PrSCs and PrECs for 2 days with resveratrol modulated its uptake and selectively increased its distribution to the membrane and organelle compartments. Resveratrol affinity column chromatography studies showed differential expression of a previously identified resveratrol-targeting protein, quinone reductase 2 (QR2), in PrSCs and PrECs. Flow cytometric analysis comparing resveratrol-treated and untreated PrSCs showed a large decrease in G1-phase and a concomitant increase in S and G2/M-phases of the cell cycle. These results suggest that resveratrol suppresses PrSC proliferation by affecting cell cycle phase distribution, which may involve the participation by QR2.
基金supported by the National Natural Science Foundation of China (Nos. 41673042,41876042,and 41776049)。
文摘Glycerol dialkyl glycerol tetraethers(GDGTs), specific membrane lipids synthesized mainly by bacteria and archaea, can be divided into isoprenoids and methyl branched alkyl GDGTs(i GDGTs and brGDGTs, respectively). Three GDGTs groups(i GDGTs, brGDGTs, and other membrane lipids) in a peat sample were separated and collected in this study using semi-preparative high-performance liquid chromatography(HPLC) and silica gel column chromatography. The obtained recoveries for the whole analytical procedure were 85% – 55% using semi-preparative HPLC and 70% – 20% using gel column chromatography. In addition, in each method, the recoveries of brGDGTs and iGDGTs were similar, regardless of the huge difference in their contents. High purity was found in the fractionated groups, determined based on ether cleavage and reduction. Moreover, the semi-preparative HPLC method could realize a better separation efficiency than the silica gel method, but it was time-consuming and required expensive equipment, while the silica gel chromatography method featured merits of time saving and convenient operation at the cost of a slight reduction in separation efficiency. The advantages of the silica gel method make it an operational laboratory method for batch experiments and isotopic studies.
文摘Nicotine is an alkaloid mainly found in leaves of tobacco and is used therapeutically for patients seeking relief from tobacco dependence in the form of products such as gums, patches, lozenges etc. In these products, majorly nicotine derived from tobacco is used which is inherently contaminated with undesirable nicotine related substances as impurities at low levels and is difficult to remove. Hence, use of synthetic nicotine is considered as an option which will be devoid of such impurities. In this work, a short and efficient synthesis of (R) and (S) nicotine was achieved by leveraging a key esterification between racemic homoallylic alcohol intermediate (2) and (S)-Ibuprofen (3) to produce diastereomers (5a) and (5b) which were easily separable under standard column chromatography conditions. Use of (S)-Ibuprofen (3) as a chiral resolving agent constitutes a novel approach which was not reported earlier. A subsequent hydrolysis of the diastereomers furnished the homoallylic alcohol intermediates (S)-6a and (R)-6a with high enantiopurity, which was effectively translated to the corresponding (R)-nicotine and (S)-nicotine respectively.
基金Supported by the National S&T Major Project of China(Nos.2009ZX09502-012 and 2009ZX09304-002)the Natural Science Foundation of Zhejiang Province, China(No.R2080693)
文摘A simple, reliable and accurate high performance liquid chromatography(HPLC) coupled with a UV detector at varied wavelength was developed for the quantitation of two types of anti-carcinogenic compounds, namely, Kushen alkaloids(KS-As) and Kushen flavonoids(KS-Fs), in Kushen. Their remarkable difference in physicochemical properties was circumvented by integrated optimization of column and mobile phase. The separation was achieved on an alkaline-resisting C18 column via gradient elution with acetonitrile(ACN) and 0.025%(volume ratio) diethylamine(DEA) in water as mobile phase. The flow rate was 0.7 mL/min, and the column temperature was maintained at 35 °C. UV detection wavelength was set at 225 nm to monitor KS-As, and then changed to 335 nm for KS-Fs at 26th min, which was kept for 30 min before returning to the original wavelength. All the calibration curves show good linearity(r20.999) within test ranges. The intra- and inter-day precision values of these components were less than 3.82%, and the average recovery rates obtained were in a range of 97.24%―102.64% for all the samples with RSD below 3.94%. This assay was successfully applied to determining the major active components in commercial herbal samples of Kushen. Moreover, the possible relationship between sample and the geographical region was visualized based on the contents of the 6 compounds in the light of principal component analysis(PCA). The results suggest that the proposed method facilitates the quality control of Kushen.
基金Supported by the Opening Foundation of the State Key Laboratory of Space Medicine Fundamentals and Application,Chinese Astronaut Research and Training Center(SMFA15K04)
文摘A simple,rapid and sensitive method for the quantification of camellianin B in Cephalotaxus sinensis(C.sinensis)a natural plant with anti-hyperglycemic effect,was developed and validated by reversed phase liquid chromatography.Chromatographic separation was achieved on a C18 column and an isocratic elution was carried out at a flow-rate of 1.0 mL·min-1 with the acetonitrile-water containing0.1%formic acid(19∶81,v/v).The detection wavelength was set at 330 nm.The calibration curve was linear over the concentration range of 0.25-50μg·mL-1 with correlation coefficients larger than0.999 5.The limit of detection and limit of quantification were 0.09μg·mL-1and 0.25μg·mL-1,respectively.The precisions and accuracy for all samples were acceptable.The validated method has been successfully applied for the quantification of camellianin B in C.sinensis harvested in different months and may also be used as the quality evaluation of this herb medicine.
文摘This article deals with extraction and purification of deguelin,which is a main rotenoid occurred in the root of Derris trifoliate Lour.Deguelin has gained much attention of scientists because of its potential ability to inhibit cancer cell proliferation.The dried root powder was extracted with ethanol by ultrasonic-assisted extraction for 30 min,and then filtrated and concentrated to give pasty concentrate.The concentrate was loaded onto silica gel column chromatography subsequently;and the chemical was eluted using a binary solvent mixture of petroleum ether(60-90ºC)-ethyl acetate(4:1,v/v).All tentative identification was carried out by high performance liquid chromatography(HPLC).Most crystal of deguelin was obtained after the fractions mainly containing deguelin were pooled and placed in the dark at 4ºC for three days.With recrystallization from carbon tetrachloride for three times,the purity of deguelin crystal was 99.15%and the yield was 0.55%of the dried weight of D.trifoliate Lour root.
文摘The influencing factors of extracellular polysac-charide(EPS)produced from a strain of lactic acid bacteria(LAB L15)were studied by using the phenol-H2SO4 method.It was demonstrated that the strain produced EPS at the most amount when it was incubated for 40-48 h and when the pH value was 4 under 30℃.Glucose was the most suitable carbon source for LAB-producing EPS.The rough EPS was obtained from L15 culture after centrifugation,dialysis,deprotein,decoloration,and ethanol-precipitation.The sample was at least composed of two polysaccharides that were completely different in molecular weight and the amount.The purified EPS was passed through the SephadexG-200 column and it showed that it was a sample purified by thin layer chromatography.
基金Supported by University Grants Commission,New Delhi with Grant number(UGC-F.14-2(SC)/2009(SA-III).
文摘Objective:To screen seaweed Sargassum wightii(S.wightii)for bioactive natural substance against marine ornamental fish bacterial pathogens,and also study the antioxidant properties,brine shrimp toxicity effect.Methods:Crude extract was made using three solvents(acetone,ethanol and methanol)and screened for antibacterial activity and purified by column chromatography,purified fractions obtained were tested for the activity.The 1st fraction of acetone extract showed maximum activity,this was again subjected for purification and obtained three sub-fractions also tested for the activity.Total phenols and flavonoid contents,reducing power,free radical scavenging activities(DPPH and H_(2)O_(2))and brine shrimp toxicity were also studied using purified acetone extract followed by standard methods.Results:The purified acetone extract showed maximum activity against eight pathogens among ten.GC-MS results revealed two major compounds such as 24-methylene cholesterol(79.9%)and methyl oleate(30.3%)which presented in higher percentage in purified extract and had highest phenols and flavonoid contents,reducing power,free radical scavenging activities,and also showed less toxicity effect.In he present study,the purified extract of S.wightii had potential antibacterial activity against Aeromonas hydrophila[(22.25±0.35)mm]and minimum activity against Streptococcus sp.[(10.00±0.00)mm].The purified extract of S.wightii also had potential total antioxidant activity of(3.87±0.04)μg at 100μg/mL concentration and the lowest activity was exhibited(1.52±0.01)μg at 25μg/mL.Conclusions:The present study concluded that the brown seaweed,S.wightii has potential antimicrobial and antioxidant activities,which can be used in aquaculture industry for treated bacterial diseases in infected fishes.
基金financially supported by the Scientific and Technological Innovation Project Foundation of Tianjin(No.06FZZDSH00404).
文摘A reliable and accurate liquid chromatography with evaporative light scattering detection(LC-ELSD)method was developed for simultaneous determination of five constituents in Xue-Fu-Zhu-Yu capsule,a widely used prescription of traditional Chinese medicine(TCM).The chromatographic separation was performed on a Symmetry C_(18)column(150 mm×4.6 mm,5.0μm)using gradient elution of acetonitrile and water(containing 1.0%acetic acid).The flow rate was 0.6 mL/min and the temperature of column was 30℃.A good linearity correlation was obtained over the investigated concentration ranges.Recoveries of the five components varied from 97.31%to 99.84%(RSD<4.0%).The validated method was successfully applied to the quality assessment of Xue-Fu-Zhu-Yu capsule.