Chromatographic fingerprinting has been perceived as an essential tool for assessing quality and chemical equivalence of traditional Chinese medicine.However,this pattern-oriented approach still has some weak points i...Chromatographic fingerprinting has been perceived as an essential tool for assessing quality and chemical equivalence of traditional Chinese medicine.However,this pattern-oriented approach still has some weak points in terms of chemical coverage and robustness.In this work,we proposed a multiple reaction monitoring(MRM)-based fingerprinting method in which approximately 100 constituents were simultaneously detected for quality assessment.The derivative MRM approach was employed to rapidly design MRM transitions independent of chemical standards,based on which the large-scale fingerprinting method was efficiently established.This approach was exemplified on QiShenYiQi Pill(QSYQ),a traditional Chinese medicine-derived drug product,and its robustness was systematically evaluated by four indices:clustering analysis by principal component analysis,similarity analysis by the congruence coefficient,the number of separated peaks,and the peak area proportion of separated peaks.Compared with conventional ultraviolet-based fingerprints,the MRM fingerprints provided not only better discriminatory capacity for the tested normal/abnormal QSYQ samples,but also higher robustness under different chromatographic conditions(i.e.,flow rate,apparent pH,column temperature,and column).The result also showed for such large-scale fingerprints including a large number of peaks,the angle cosine measure after min-max normalization was more suitable for setting a decision criterion than the unnormalized algorithm.This proof-of-concept application gives evidence that combining MRM technique with proper similarity analysis metrices can provide a highly sensitive,robust and comprehensive analytical approach for quality assessment of traditional Chinese medicine.展开更多
A novel high sensihtity, small-volume photothermal intheence detector has beenintroduced for capillap zone electrophoresis separation analysis. The utility of thes sdriulboconstecheque for momtomp chelating reachon of...A novel high sensihtity, small-volume photothermal intheence detector has beenintroduced for capillap zone electrophoresis separation analysis. The utility of thes sdriulboconstecheque for momtomp chelating reachon of light rare earth with tribromoarsenazo has beenreported.展开更多
Many kinds of pesticides have been developed and used to yield a good harvest but the residues in agricul-tural products cause health problems. It is important to keep watch on these residues by using adequate methods...Many kinds of pesticides have been developed and used to yield a good harvest but the residues in agricul-tural products cause health problems. It is important to keep watch on these residues by using adequate methods of analysis. Pretreatment such as gel permeation chromatography (GPC) or column chromatography is often needed for the quantitative analysis of pesticide in agricultural products by conventional methods such as gas chromatography/low resolving power mass spectrometry (GC/LRMS). However, these pretreat-ments need a lot of work and take time. New methods saving the necessity of these pretreatments have been desired. We have applied selected reaction monitoring (SRM) to quantitatively determine cypermethrin residues in Perilla frutescens samples and compared the results with LRMS and HRMS in SIM mode. A background peak caused by the matrix overlapped the cypermethrin peak in the analysis using LRMS. SRM and HRMS in SIM mode provided chromatograms without matrix interference. The high selectivity of the product ion (m/z 127) produced from precursor ion (m/z 163) isolated the target peaks from the matrix peaks when using SRM. This method eliminates the pretreatment step, thus saving time and simplify ing the ana-lytical process.展开更多
Identification and quantification of low abundance growth factors and regulators in complex biological samples still present a challenging task in analytical biochemistry. Immunoassays are often used for such purpose ...Identification and quantification of low abundance growth factors and regulators in complex biological samples still present a challenging task in analytical biochemistry. Immunoassays are often used for such purpose but immunoassays face limitation of both availability and qualities of antibody reagents that are necessary for development of immune assays. With genomics data base available, mass spectrometry (MS) can analyze protein tryptic peptides directly for quantitative determination of proteins. In this study, we report a method for detection of matrix metalloproteinase 1 (MMP1), an important extracellular matrix modulator, in human breast cancer cells by quadrupole time-of-flight (Q-TOF) MS. Absolute quantification of MMP1 was conducted using the selected reaction monitoring (SRM) on a triple quadrupole (Triple-Quad) MS via transitions selected from MMP1 tryptic peptides using non isotope labeled MMP1 protein as a titration standard. In comparison with immune based assay, this MS method showed picogram level sensitivity for quantitative determination of MMP1 intotal cell lysates. Our results demonstrated the feasibility of absolute quantification of low abundance proteins using label-free protein standard by mass spectrometry. Therefore, this method provides not only advantages of high sensitivity but also cost saving in comparison with the commonly used mass spectrometry that currently employs isotype labeled proteins for quantitative analysis.展开更多
Plant viruses in the families Luteoviridae and Geminiviridae are phloem restricted and are transmitted in a persistent,circulative manner by homopteran insects.Using fluorescence 2-D difference gel electrophoresis to ...Plant viruses in the families Luteoviridae and Geminiviridae are phloem restricted and are transmitted in a persistent,circulative manner by homopteran insects.Using fluorescence 2-D difference gel electrophoresis to compare the proteomes of F2 genotypes of Schizaphis graminum segregating for virus transmission ability,we recently discovered a panel of protein biomarkers that predict vector competency.Here we used aphid and whitefly nucleotide and expressed sequence tag database mining to test whether these biomarkers are conserved in other homopteran insects.S.graminum gene homologs that shared a high degree of predicted amino acid identity were discovered in two other aphid species and in the whitefly Bemisia tabaci.Selected reaction monitoring mass spectrometry was used to validate the expression of these biomarkers proteins in multiple aphid vector species.The conservation of these proteins in multiple insect taxa that transmit plant viruses along the circulative transmission pathway creates the opportunity to use these biomarkers to rapidly identify insect populations that are the most efficient vectors and allow them to be targeted for control prior to the spread of virus within a crop.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.81803714)the Fundamental Research Funds for the Central Universities(Grant No.2019QNA7041).
文摘Chromatographic fingerprinting has been perceived as an essential tool for assessing quality and chemical equivalence of traditional Chinese medicine.However,this pattern-oriented approach still has some weak points in terms of chemical coverage and robustness.In this work,we proposed a multiple reaction monitoring(MRM)-based fingerprinting method in which approximately 100 constituents were simultaneously detected for quality assessment.The derivative MRM approach was employed to rapidly design MRM transitions independent of chemical standards,based on which the large-scale fingerprinting method was efficiently established.This approach was exemplified on QiShenYiQi Pill(QSYQ),a traditional Chinese medicine-derived drug product,and its robustness was systematically evaluated by four indices:clustering analysis by principal component analysis,similarity analysis by the congruence coefficient,the number of separated peaks,and the peak area proportion of separated peaks.Compared with conventional ultraviolet-based fingerprints,the MRM fingerprints provided not only better discriminatory capacity for the tested normal/abnormal QSYQ samples,but also higher robustness under different chromatographic conditions(i.e.,flow rate,apparent pH,column temperature,and column).The result also showed for such large-scale fingerprints including a large number of peaks,the angle cosine measure after min-max normalization was more suitable for setting a decision criterion than the unnormalized algorithm.This proof-of-concept application gives evidence that combining MRM technique with proper similarity analysis metrices can provide a highly sensitive,robust and comprehensive analytical approach for quality assessment of traditional Chinese medicine.
文摘A novel high sensihtity, small-volume photothermal intheence detector has beenintroduced for capillap zone electrophoresis separation analysis. The utility of thes sdriulboconstecheque for momtomp chelating reachon of light rare earth with tribromoarsenazo has beenreported.
文摘Many kinds of pesticides have been developed and used to yield a good harvest but the residues in agricul-tural products cause health problems. It is important to keep watch on these residues by using adequate methods of analysis. Pretreatment such as gel permeation chromatography (GPC) or column chromatography is often needed for the quantitative analysis of pesticide in agricultural products by conventional methods such as gas chromatography/low resolving power mass spectrometry (GC/LRMS). However, these pretreat-ments need a lot of work and take time. New methods saving the necessity of these pretreatments have been desired. We have applied selected reaction monitoring (SRM) to quantitatively determine cypermethrin residues in Perilla frutescens samples and compared the results with LRMS and HRMS in SIM mode. A background peak caused by the matrix overlapped the cypermethrin peak in the analysis using LRMS. SRM and HRMS in SIM mode provided chromatograms without matrix interference. The high selectivity of the product ion (m/z 127) produced from precursor ion (m/z 163) isolated the target peaks from the matrix peaks when using SRM. This method eliminates the pretreatment step, thus saving time and simplify ing the ana-lytical process.
文摘Identification and quantification of low abundance growth factors and regulators in complex biological samples still present a challenging task in analytical biochemistry. Immunoassays are often used for such purpose but immunoassays face limitation of both availability and qualities of antibody reagents that are necessary for development of immune assays. With genomics data base available, mass spectrometry (MS) can analyze protein tryptic peptides directly for quantitative determination of proteins. In this study, we report a method for detection of matrix metalloproteinase 1 (MMP1), an important extracellular matrix modulator, in human breast cancer cells by quadrupole time-of-flight (Q-TOF) MS. Absolute quantification of MMP1 was conducted using the selected reaction monitoring (SRM) on a triple quadrupole (Triple-Quad) MS via transitions selected from MMP1 tryptic peptides using non isotope labeled MMP1 protein as a titration standard. In comparison with immune based assay, this MS method showed picogram level sensitivity for quantitative determination of MMP1 intotal cell lysates. Our results demonstrated the feasibility of absolute quantification of low abundance proteins using label-free protein standard by mass spectrometry. Therefore, this method provides not only advantages of high sensitivity but also cost saving in comparison with the commonly used mass spectrometry that currently employs isotype labeled proteins for quantitative analysis.
基金supported by NSF BREAD IOS:1109989,USDA-NRI 2007-04567,NSFDBI-0606596USDA-ARS 764 CRIS projects1907-101-16,1907-21000-024/25-00DNIH/NCRR funded Yeast Resource Center P41RR01182
文摘Plant viruses in the families Luteoviridae and Geminiviridae are phloem restricted and are transmitted in a persistent,circulative manner by homopteran insects.Using fluorescence 2-D difference gel electrophoresis to compare the proteomes of F2 genotypes of Schizaphis graminum segregating for virus transmission ability,we recently discovered a panel of protein biomarkers that predict vector competency.Here we used aphid and whitefly nucleotide and expressed sequence tag database mining to test whether these biomarkers are conserved in other homopteran insects.S.graminum gene homologs that shared a high degree of predicted amino acid identity were discovered in two other aphid species and in the whitefly Bemisia tabaci.Selected reaction monitoring mass spectrometry was used to validate the expression of these biomarkers proteins in multiple aphid vector species.The conservation of these proteins in multiple insect taxa that transmit plant viruses along the circulative transmission pathway creates the opportunity to use these biomarkers to rapidly identify insect populations that are the most efficient vectors and allow them to be targeted for control prior to the spread of virus within a crop.
