目的:对LC-UV和LC-MS在山楂叶多元酚类成分分析中的应用进行方法学比较。方法:采用高效液相色谱并联双检测器(VWD和MSD)法。色谱柱为Lichrospher C18(250×4.6 mm I.D.,5μm);流动相A为乙腈,B为0.5%甲酸溶液,梯度洗脱,0-12 min A由1...目的:对LC-UV和LC-MS在山楂叶多元酚类成分分析中的应用进行方法学比较。方法:采用高效液相色谱并联双检测器(VWD和MSD)法。色谱柱为Lichrospher C18(250×4.6 mm I.D.,5μm);流动相A为乙腈,B为0.5%甲酸溶液,梯度洗脱,0-12 min A由11%-17%,12-30 min A由17%-18%,30-45 min A由18%-40%,45-60 minA由40%-100%;流速为1ml/min,三向分流阀分流进入MSD和VWD进行检测;柱温30℃;进样量10μl。结果:LC-MS灵敏度比HPLC法高10倍以上,在检测样品中微量成分时具有很大的优势;另外,LC-MS是根据tR和m/z两项指标来确定成分的类型,对于某些用LC-UV方法不能得到良好分离的组分或在LC-UV图谱上保留时间与对照品相近的其它成分,可以选用选择性离子检测(SIM)进行分析,能避免这些成分的干扰,因而具有高度的选择性和专属性。而LC-UV法操作简便,成本低,流动相选择面较广,因而分离度往往比LC-MS高,在检测样品中具有较好的紫外吸收、较好的分离度以及含量较高的成分时,LC-UV法以其高精密度和高稳定性完全可以达到LC-MS同样的检测结果。结论:LC-MS和LC-UV在山楂叶多元酚类成分的定量分析方面各有特色,可根据不同的检测指标选用不同的检测器。展开更多
As a part of the ongoing search for new constituents of Stemona species in China, chemical investigation of Stemona sessilifolia, a plant used in the traditional Chinese medicine to treat respiratory disorders, was ca...As a part of the ongoing search for new constituents of Stemona species in China, chemical investigation of Stemona sessilifolia, a plant used in the traditional Chinese medicine to treat respiratory disorders, was carried out. To identify the chemical components rapidly, a selected sample of S. sessilifolia containing bibenzyls was tested using LC-ESIMS and analyzed further using stop-flow LC-UV-NMR, which was sensitive for the detection of the main constituents. LC microfractions were collected using the LC-UV-NMR technique and HR-EIMS off-line analysis was cartied out on the collected fractions. This chemical screening strategy allowed for the on-line identification of the main constituents of S. sessilifolia and provided information that was useful for a further peak-guided isolation procedure. Using these methods, four bibenzyls were isolated： two known compounds, 3,5-dihydroxy-4-methyl bibenzyl（1） and 3, 5-dihydroxy-2＇-methoxy-4-methyl bibenzyl （ 2 ）, and two novel compounds, 3,3＇-dihydroxy-5, 6＇-dimethoxy bibenzyl（3） and 3,5-dihydroxy-2＇, 5＇-dimethoxy bibenzyl （4）.展开更多
Five different quorum sensing peptides(QSP) were iodinated using different iodination techniques. These iodinated peptides were analyzed using a C18 reversed phase HPLC system, applying a linear gradient of water and ...Five different quorum sensing peptides(QSP) were iodinated using different iodination techniques. These iodinated peptides were analyzed using a C18 reversed phase HPLC system, applying a linear gradient of water and acetonitrile containing 0.1%(m/v) formic acid as mobile phase. Electrospray ionization(ESI)ion trap mass spectrometry was used for the identification of the modified peptides, while semi-quantification was performed using total ion current(TIC) spectra. Non-iodinated peptides and mono-and diiodinated peptides(NIP, MIP and DIP respectively) were well separated and eluted in that order. Depending on the used iodination method, iodination yields varied from low(2%) to high(57%).展开更多
Method development for determination of isoflavones in kudzu was achieved by HPLC/UV/ESI-MSD. Us- ing three kudzu species of Pueraria lobata, P. thomsonii and P. edulis, and analyzing the isoflavones sepa- rately by s...Method development for determination of isoflavones in kudzu was achieved by HPLC/UV/ESI-MSD. Us- ing three kudzu species of Pueraria lobata, P. thomsonii and P. edulis, and analyzing the isoflavones sepa- rately by species and from different plant tissues (roots, stems, leaves, flowers and fruits) in each species, a total of 25 isoflavones were identified by their molecular ions and characteristic fragment ion peaks using LC/MSD under MS and MS/MS mode, and in comparison with standard isoflavones. Two main chemical groups were identified: 1) 8-C-glycosyl isoflavone of puerarin and the analogues of 5-OH puerarin, 3’-OH puerarin, 3’-OMe puerarin, and their glycosides;and 2) daidzein, genistein, glycitein and their glycosyl and malonyl derivatives, which are similar to those known in soy. To accurately quantitate total isoflavones, acidic hydrolysis during extraction of kudzu samples was applied to convert the oxygen glycosides into their respective isoflavone aglycones of daidzein, genistein and glycitein, or non-hydrolyzed carbon glycosides of puerarin, 5-OH puerarin, 3’-OH puerarin and 3’-OMe puerarin. Under the multiple optimized conditions, all seven isoflavones in acidic hydrolyzed kudzu extracts were successfully separated within 30 min and quanti- fied individually with calycosin used as internal standard by both UV and MS detectors. For the quantitative study, several standards e.g. 5-OH puerarin, 3’-OH puerarin and 3’-OMe puerarin are not commercially available. Using polyamide, sephdex-LH20 chromatography and Prep-HPLC, we purified these three stan- dards from kudzu extracts and then elucidated their structures by UV, MS and NMR spectrometric methods. This is the first method to simultaneously quantitate all the isoflavones in kudzu.展开更多
文摘目的:对LC-UV和LC-MS在山楂叶多元酚类成分分析中的应用进行方法学比较。方法:采用高效液相色谱并联双检测器(VWD和MSD)法。色谱柱为Lichrospher C18(250×4.6 mm I.D.,5μm);流动相A为乙腈,B为0.5%甲酸溶液,梯度洗脱,0-12 min A由11%-17%,12-30 min A由17%-18%,30-45 min A由18%-40%,45-60 minA由40%-100%;流速为1ml/min,三向分流阀分流进入MSD和VWD进行检测;柱温30℃;进样量10μl。结果:LC-MS灵敏度比HPLC法高10倍以上,在检测样品中微量成分时具有很大的优势;另外,LC-MS是根据tR和m/z两项指标来确定成分的类型,对于某些用LC-UV方法不能得到良好分离的组分或在LC-UV图谱上保留时间与对照品相近的其它成分,可以选用选择性离子检测(SIM)进行分析,能避免这些成分的干扰,因而具有高度的选择性和专属性。而LC-UV法操作简便,成本低,流动相选择面较广,因而分离度往往比LC-MS高,在检测样品中具有较好的紫外吸收、较好的分离度以及含量较高的成分时,LC-UV法以其高精密度和高稳定性完全可以达到LC-MS同样的检测结果。结论:LC-MS和LC-UV在山楂叶多元酚类成分的定量分析方面各有特色,可根据不同的检测指标选用不同的检测器。
基金Supported by Science and Technology Committee of Shanghai, P R China(No 036505003)
文摘As a part of the ongoing search for new constituents of Stemona species in China, chemical investigation of Stemona sessilifolia, a plant used in the traditional Chinese medicine to treat respiratory disorders, was carried out. To identify the chemical components rapidly, a selected sample of S. sessilifolia containing bibenzyls was tested using LC-ESIMS and analyzed further using stop-flow LC-UV-NMR, which was sensitive for the detection of the main constituents. LC microfractions were collected using the LC-UV-NMR technique and HR-EIMS off-line analysis was cartied out on the collected fractions. This chemical screening strategy allowed for the on-line identification of the main constituents of S. sessilifolia and provided information that was useful for a further peak-guided isolation procedure. Using these methods, four bibenzyls were isolated： two known compounds, 3,5-dihydroxy-4-methyl bibenzyl（1） and 3, 5-dihydroxy-2＇-methoxy-4-methyl bibenzyl （ 2 ）, and two novel compounds, 3,3＇-dihydroxy-5, 6＇-dimethoxy bibenzyl（3） and 3,5-dihydroxy-2＇, 5＇-dimethoxy bibenzyl （4）.
基金the‘Research Foundation–Flanders(FWO)’(Grant no.1S21017N to Nathan Debunne)the‘Institute for the Promotion of Innovation through Science and Technology in Flanders(IWT-Vlaanderen)’(Grant no.131356 to Frederick Verbeke)
文摘Five different quorum sensing peptides(QSP) were iodinated using different iodination techniques. These iodinated peptides were analyzed using a C18 reversed phase HPLC system, applying a linear gradient of water and acetonitrile containing 0.1%(m/v) formic acid as mobile phase. Electrospray ionization(ESI)ion trap mass spectrometry was used for the identification of the modified peptides, while semi-quantification was performed using total ion current(TIC) spectra. Non-iodinated peptides and mono-and diiodinated peptides(NIP, MIP and DIP respectively) were well separated and eluted in that order. Depending on the used iodination method, iodination yields varied from low(2%) to high(57%).
文摘Method development for determination of isoflavones in kudzu was achieved by HPLC/UV/ESI-MSD. Us- ing three kudzu species of Pueraria lobata, P. thomsonii and P. edulis, and analyzing the isoflavones sepa- rately by species and from different plant tissues (roots, stems, leaves, flowers and fruits) in each species, a total of 25 isoflavones were identified by their molecular ions and characteristic fragment ion peaks using LC/MSD under MS and MS/MS mode, and in comparison with standard isoflavones. Two main chemical groups were identified: 1) 8-C-glycosyl isoflavone of puerarin and the analogues of 5-OH puerarin, 3’-OH puerarin, 3’-OMe puerarin, and their glycosides;and 2) daidzein, genistein, glycitein and their glycosyl and malonyl derivatives, which are similar to those known in soy. To accurately quantitate total isoflavones, acidic hydrolysis during extraction of kudzu samples was applied to convert the oxygen glycosides into their respective isoflavone aglycones of daidzein, genistein and glycitein, or non-hydrolyzed carbon glycosides of puerarin, 5-OH puerarin, 3’-OH puerarin and 3’-OMe puerarin. Under the multiple optimized conditions, all seven isoflavones in acidic hydrolyzed kudzu extracts were successfully separated within 30 min and quanti- fied individually with calycosin used as internal standard by both UV and MS detectors. For the quantitative study, several standards e.g. 5-OH puerarin, 3’-OH puerarin and 3’-OMe puerarin are not commercially available. Using polyamide, sephdex-LH20 chromatography and Prep-HPLC, we purified these three stan- dards from kudzu extracts and then elucidated their structures by UV, MS and NMR spectrometric methods. This is the first method to simultaneously quantitate all the isoflavones in kudzu.
