Biological mass spectrometry has received a great progress in recent years.The osteopontin(OPN) isolated and purified from the human milk was studied by HPLC using SCX and C4 columns.After hydrolyzing the purified OPN...Biological mass spectrometry has received a great progress in recent years.The osteopontin(OPN) isolated and purified from the human milk was studied by HPLC using SCX and C4 columns.After hydrolyzing the purified OPN sample by trypsin,the correlative polypeptide fragments GDSVVYGLR and QNLLAPQTLPSK were obtained by FT-ICR-MS.It showed that the method of nano-spray HPLC combined with FT-ICR-MS and Mascot search was very efficient for the analysis of the purified OPN and its polypeptide fragments.Further study provides more academic theories of their different modifications and the relative bioactivities.展开更多
FT-ICR-MS technology has significant sensitivity and dynamic range,enabling the detection of different fragmentations of peptides and proteins at lower and lower levels.In the bottom-up approach,by far the most freque...FT-ICR-MS technology has significant sensitivity and dynamic range,enabling the detection of different fragmentations of peptides and proteins at lower and lower levels.In the bottom-up approach,by far the most frequently used proteomics approach,a single LC-MS run can reveal tens and even hundreds of useful information.For each peptide selected for MS/MS,two data-files were generated,one for ECD and another one for CAD.They were merged as described and submitted to the Mascot search engine using the protein database.These thresholds ensure almost 100% statistical confident in the peptide identification.展开更多
The phosphorothioate oligonucleotides are used more and more for cancer treatment.Fast analysis of phosphorothioate oligonucleotide is important for quality control of this drug.In this paper,FT-ICR-MS was used to ana...The phosphorothioate oligonucleotides are used more and more for cancer treatment.Fast analysis of phosphorothioate oligonucleotide is important for quality control of this drug.In this paper,FT-ICR-MS was used to analyze a phosphorothioate oligonucleotide with 6 321 u.Experimental results showed that accurate relative molecular mass of phosphorothioate oligonucleotide determined by FT-ICR-MS can be used for confirmation of its composition.展开更多
目的采用高效液相色谱串联高分辨傅立叶变换离子回旋共振质谱(High performance liquid chromatography tandem high resolution Fourier transform ion cyclotron resonance mass spectrometry,HPLC-FTICR-MS)技术对芪红水煎剂的化学...目的采用高效液相色谱串联高分辨傅立叶变换离子回旋共振质谱(High performance liquid chromatography tandem high resolution Fourier transform ion cyclotron resonance mass spectrometry,HPLC-FTICR-MS)技术对芪红水煎剂的化学成分进行快速表征,建立高效液相色谱法(high-performance liquid chromatography,HPLC)对芪红水煎剂中多成分进行含量测定,分析黄芪、水红花子配伍对主要成分溶出的影响,完善其质量控制。方法HPLC-FT-ICR-MS采用电喷雾离子化源(Electrospray ionization source,ESI)负离子模式检测,根据高分辨数据及二级质谱信息结合对照品数据及相关文献对芪红水煎剂化学成分进行快速鉴定;芪红水煎剂中6种主要成分的HPLC含量测定采用Venusil MP-C18色谱柱(4.6 mm×250 mm,5μm),甲醇-0.5%磷酸溶液梯度洗脱,流速1.0 mL·min^-1,检测波长254 nm和290 nm。结果对芪红水煎剂提取物中的26个化学成分进行表征,其中9个成分来源于水红花子,17个成分来源于黄芪。与单味药相比,芪红水煎剂中毛蕊异黄酮-7-O-β-D-葡萄糖苷、N-反式-阿魏酰酪胺、槲皮素的煎出量均明显增加(P<0.01),花旗松素、芒柄花素的煎出量明显降低(P<0.01),毛蕊异黄酮煎出量变化不明显(P>0.05)。结论该方法可快速对芪红水煎剂中的主要成分进行定性分析,所建多成分含量测定方法可以反映水红花子和黄芪共煎后对主要成分溶出率的影响,为进一步研究其配伍规律提供理论依据。展开更多
The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization(ESI) Fourier tran...The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). The acid class(heteroatom number), type(z numbers) and carbon number distributions were positively characterized. It was found out that the total acid number(TAN) of SL crude decreased after true boiling point distillation, and the abundance of O2 class in mass spectra was also found to be reduced from 67.6% to 34.5% in SL TBP mixed crude as measured by MS spectra, indicating to a potential carboxylic acid decomposition. However, it was interesting that the carboxylic acids type distribution in both oils was almost the same although their relative abundance in SL TBP mixed crude turned to be much lower, suggesting that various petroleum carboxylic acid types have the similar thermal decomposition reaction behavior. Furthermore, for each O2 type of acids in SL TBP mixed crude, the abundance of carboxylic acids with carbon number higher than 35 was reduced greatly, especially for those with carbon number higher than 60, the mass peaks of which were nearly totally removed, indicating that the large carboxylic acid molecules in heavy fractions decomposed more significantly because of longer heating time during the true boiling point distillation process. As a result, the reduction of TAN may be caused by the thermal decomposition of carboxylic acids especially those with high carbon number, suggesting that quick distillation or much lower pressure is required to avoid the thermal decomposition.展开更多
Milk as a key element for infant nutrition represents the only source of feeding for newborns and infants, breast-feeding milk normally contains several bioactive proteins or peptides useful for the development of the...Milk as a key element for infant nutrition represents the only source of feeding for newborns and infants, breast-feeding milk normally contains several bioactive proteins or peptides useful for the development of the immune system that protects infants from diseases. Osteopontin（OPN） plays a distinct role during the processes of lactation, Some studies on OPN isolated and purified from the human milk via HPLC on SCX and Ca columns adopted biological mass spectrometry. After digesting the purified OPN sample with trypsin, the typical correlative polypeptide fragments GDSVVYGLR and QNLLAPQTLPSK are identified by FT-ICR-MS. The rapid identification of OPN is assumed to be reasonably well behaving in a standard bottom-up experiment. It shows that nano-spray HPLC combined with FT-ICR-MS and Mascot search can be used as a high efficient method for the identification of purified OPN and its polypeptide fragments. Further study will provide more academic theories of their different modifications and the bioactivity as well.展开更多
The catalytic esterification reaction was used to decrease total acid number(TAN) of crude oil by converting naphthenic acids to naphthenic acid esters in the presence of Zn-Al hydrotalcite used as the catalyst and gl...The catalytic esterification reaction was used to decrease total acid number(TAN) of crude oil by converting naphthenic acids to naphthenic acid esters in the presence of Zn-Al hydrotalcite used as the catalyst and glycol used as the reactant. The crude oil and its corresponding esterified oil were characterized by the negative-ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). Six acidic class species, O_2, O_1, N_1, N_2, N_1O_1 and N_1O_2 were assigned in the negative-ion spectrum both in the crude oil and its esterified oil. Among the identified acidic compounds, the O2 class was dominant. The relative abundance of O_2 class species was much higher than other acidic class species in crude oil, while it was significantly decreased after esterification. The most abundant O_2 class species had a carbon number of 30-34 and a double-bond equivalence(DBE) value of 5 before and after esterification. It could be concluded that the naphthenic acids in crude oil can be esterified to lower its TAN value, and each of them seems to exhibit identical esterification efficiency approximately due to the similar DBE versus the-carbon number distribution before and after esterification.展开更多
文摘Biological mass spectrometry has received a great progress in recent years.The osteopontin(OPN) isolated and purified from the human milk was studied by HPLC using SCX and C4 columns.After hydrolyzing the purified OPN sample by trypsin,the correlative polypeptide fragments GDSVVYGLR and QNLLAPQTLPSK were obtained by FT-ICR-MS.It showed that the method of nano-spray HPLC combined with FT-ICR-MS and Mascot search was very efficient for the analysis of the purified OPN and its polypeptide fragments.Further study provides more academic theories of their different modifications and the relative bioactivities.
文摘FT-ICR-MS technology has significant sensitivity and dynamic range,enabling the detection of different fragmentations of peptides and proteins at lower and lower levels.In the bottom-up approach,by far the most frequently used proteomics approach,a single LC-MS run can reveal tens and even hundreds of useful information.For each peptide selected for MS/MS,two data-files were generated,one for ECD and another one for CAD.They were merged as described and submitted to the Mascot search engine using the protein database.These thresholds ensure almost 100% statistical confident in the peptide identification.
文摘The phosphorothioate oligonucleotides are used more and more for cancer treatment.Fast analysis of phosphorothioate oligonucleotide is important for quality control of this drug.In this paper,FT-ICR-MS was used to analyze a phosphorothioate oligonucleotide with 6 321 u.Experimental results showed that accurate relative molecular mass of phosphorothioate oligonucleotide determined by FT-ICR-MS can be used for confirmation of its composition.
基金financially supported by the National Key Basic Research Development Program "973" Project (2006CB202501)
文摘The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). The acid class(heteroatom number), type(z numbers) and carbon number distributions were positively characterized. It was found out that the total acid number(TAN) of SL crude decreased after true boiling point distillation, and the abundance of O2 class in mass spectra was also found to be reduced from 67.6% to 34.5% in SL TBP mixed crude as measured by MS spectra, indicating to a potential carboxylic acid decomposition. However, it was interesting that the carboxylic acids type distribution in both oils was almost the same although their relative abundance in SL TBP mixed crude turned to be much lower, suggesting that various petroleum carboxylic acid types have the similar thermal decomposition reaction behavior. Furthermore, for each O2 type of acids in SL TBP mixed crude, the abundance of carboxylic acids with carbon number higher than 35 was reduced greatly, especially for those with carbon number higher than 60, the mass peaks of which were nearly totally removed, indicating that the large carboxylic acid molecules in heavy fractions decomposed more significantly because of longer heating time during the true boiling point distillation process. As a result, the reduction of TAN may be caused by the thermal decomposition of carboxylic acids especially those with high carbon number, suggesting that quick distillation or much lower pressure is required to avoid the thermal decomposition.
基金Supported by the Project from Scientific Bureau of Jilin Province, China(No.200705391)
文摘Milk as a key element for infant nutrition represents the only source of feeding for newborns and infants, breast-feeding milk normally contains several bioactive proteins or peptides useful for the development of the immune system that protects infants from diseases. Osteopontin（OPN） plays a distinct role during the processes of lactation, Some studies on OPN isolated and purified from the human milk via HPLC on SCX and Ca columns adopted biological mass spectrometry. After digesting the purified OPN sample with trypsin, the typical correlative polypeptide fragments GDSVVYGLR and QNLLAPQTLPSK are identified by FT-ICR-MS. The rapid identification of OPN is assumed to be reasonably well behaving in a standard bottom-up experiment. It shows that nano-spray HPLC combined with FT-ICR-MS and Mascot search can be used as a high efficient method for the identification of purified OPN and its polypeptide fragments. Further study will provide more academic theories of their different modifications and the bioactivity as well.
基金financially supported by the National Natural Science Foundation of China (No. 21206194)
文摘The catalytic esterification reaction was used to decrease total acid number(TAN) of crude oil by converting naphthenic acids to naphthenic acid esters in the presence of Zn-Al hydrotalcite used as the catalyst and glycol used as the reactant. The crude oil and its corresponding esterified oil were characterized by the negative-ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). Six acidic class species, O_2, O_1, N_1, N_2, N_1O_1 and N_1O_2 were assigned in the negative-ion spectrum both in the crude oil and its esterified oil. Among the identified acidic compounds, the O2 class was dominant. The relative abundance of O_2 class species was much higher than other acidic class species in crude oil, while it was significantly decreased after esterification. The most abundant O_2 class species had a carbon number of 30-34 and a double-bond equivalence(DBE) value of 5 before and after esterification. It could be concluded that the naphthenic acids in crude oil can be esterified to lower its TAN value, and each of them seems to exhibit identical esterification efficiency approximately due to the similar DBE versus the-carbon number distribution before and after esterification.
