The present study was designed to systematically investigate the ESI-MSn behavior of a complex 3, 7-O-glycosyl flavonol, kaempferol 3-O-α-L-[2,3-di-O-β-D-（6-E-p-coumaroyl）glucopyranosyl]-rhamnopyranosyl-7-O-α-L-r...The present study was designed to systematically investigate the ESI-MSn behavior of a complex 3, 7-O-glycosyl flavonol, kaempferol 3-O-α-L-[2,3-di-O-β-D-（6-E-p-coumaroyl）glucopyranosyl]-rhamnopyranosyl-7-O-α-L-rhamnopyranoside （KO） isolated from Epimedium wushanense, and to address the elimination priority among different glycosylation sites and different sugars/substituents. The direct-infusion ESI-MSn experiment of KO was performed on a hybrid LTQ-Orbitrap Velos Pro mass spectrometer in both negative and positive ion modes by three different fragmentation mechanisms （CID, HCD, and PQD）. The CID, HCD, and PQD analyses of KO exhibited remarkable discrimination in respect of the scan range, richness, and distribution of product ions through the entire spectra. KO experienced different fragmentation pathways between two ionization modes： the negative mode CID of KO eliminated the glycosyl portions （priority： 7-sugar 〉 3-substituent and terminal substituents 〉 inner sugar） and produced aglycone product ions at m/z 284.03/285.04; however, abundant sodium-adduct B32 together with subsequent ijX30 cleavages were found characteristic for the positive mode CID-MSn. The fragmentation pathways by CID for KO were proposed by analyzing the high accuracy ESI-MS＂ data. Complementary structural information of KO regarding the aglycone and glycosyl portions was obtained by analyzing the ESI-MSn data in both ionization modes. In conclusion, the LTQ-Orbitrap method facilitates highly reliable qualitative analysis of bioactive flavonoids with three alternative fragmentation modes.展开更多
The impurities in ethyl-2-[[2′-cyanobiphenyl-4-yl] methyl] amino]-3-nitrobenzoate,an intermediate for synthesis of candesartan cilexiti,were detected by LC-MSn. The structural assignment of these impurities was carri...The impurities in ethyl-2-[[2′-cyanobiphenyl-4-yl] methyl] amino]-3-nitrobenzoate,an intermediate for synthesis of candesartan cilexiti,were detected by LC-MSn. The structural assignment of these impurities was carried out by LC-MSn using electrospray ionization source and an ion trap mass analyzer. The formation of the impurities was discussed. Also the fragmentation pathways of these compounds were studied.展开更多
Amino acid methyl ester phosphates were synthesized and determined by using positive-ion mode dectrospmy ionization mass spectrometry（ESIMS） in combination with multistage tandem mass spectrometry. The fragmentation...Amino acid methyl ester phosphates were synthesized and determined by using positive-ion mode dectrospmy ionization mass spectrometry（ESIMS） in combination with multistage tandem mass spectrometry. The fragmentation pathways were investigated, and it was observed that most fragment ions contained the phosphoryl group. It was interesting to observe that the fragmentation pathways of the protonated molecule show some differences when compared with those of the sodium ion adduct. The methoxy group of amino acid methyl ester can migrate from the carbonyl group to the phosphoryl group in the sodium ion adduct.展开更多
Background:As one of the most popular traditional Chinese medicines(TCMs)for the treatment of various liver diseases,virgate wormwood herb(Artemisia capillaris Thunb.)has a long application history in TCM practices.It...Background:As one of the most popular traditional Chinese medicines(TCMs)for the treatment of various liver diseases,virgate wormwood herb(Artemisia capillaris Thunb.)has a long application history in TCM practices.It has been well established that the chemical composition is responsible for the pronounced therapeutic spectrum of A.capillaris.Although they are comprehensive,the time-intensive liquid chromatography coupled to tandem mass spectrometry(LCeMS/MS)assays cannot fully satisfy the analytical measurement workload from many test samples.Direct infusion-MS/MS(DIeMS/MS)may be the optimal choice to achieve high-throughput analysis if the mass spectrometer can universally record MS2 spectra.Methods:According to the application of gas phase ion fractionation concept,the MS/MSALL program enables to gain MS2 spectrum for each nominal m/z value with a data-independent acquisition algorithm via segmenting the entire MS1 ion cohort into sequential ion pieces with 1 Da width,when sufficient measurement time is allowed by DI approach.Here,rapid clarification of the chemical composition was attempted for A.capillaris using DIeMS/MSALL.A.capillaris extract was imported directly into the electrospray ionization interface to obtain the MS/MSALL measurement.After the MS1-MS2 dataset was well organized,we focused on structural characterization through retrieving information from the available databases and literature.Results:Twenty-six compounds were found,including 12 caffeoyl quinic acid derivatives,7 flavonoids,and 7 compounds belonging to other chemical families.Among them,24 ones were structurally identified.Compared with the LCeMS/MS technique,DIeMS/MSALL has the advantages of low-costing,solvent-saving,and time-saving.Conclusions:Chemical profiling of A.capillaris extract was accomplished within 5 min by DIeMS/MSALL,and this technique can be an alternative choice for chemical profile characterization of TCMs due to its extraordinary high-throughput advantage.展开更多
The fragmentation patterns of a series of dispirocyclopiperazinium dibromides with strong analgesic activity during positive ion electrospray ionization mass spectrometry were analyzed. The [M-Br]^＋ 2 ions showed the...The fragmentation patterns of a series of dispirocyclopiperazinium dibromides with strong analgesic activity during positive ion electrospray ionization mass spectrometry were analyzed. The [M-Br]^＋ 2 ions showed the characteristic isotopic peaks and were assigned as the molecular ions. The loss of a 44 Dalton unit from 2 produced ion 3 [M-Br-44]^＋ and the loss of HBr from 2 formed ion 4. Besides, the carbamates 1d-1e produced extra ions [M-2Br-33]^＋. The related fragmentation mechanisms were proposed.展开更多
Flavonoid metabolism in Camptotheca acuminate remained an untapped area for years.A tandem MS approach was used and focused on the mining and characterizing of flavonoids in mature C.acuminate.Fifteen new flavonoids a...Flavonoid metabolism in Camptotheca acuminate remained an untapped area for years.A tandem MS approach was used and focused on the mining and characterizing of flavonoids in mature C.acuminate.Fifteen new flavonoids and forty-three known flavonoids,including fifteen flavone analogs,sixteen flavonol analogs,seven flavanone analogs,six chalcone analogs,four xanthone analogs,ten flavane analogs were mined and identified based on their MS/MS fragments.Fifty-three of them were firstly characterized in C.acuminate.Eight biosynthetic precursors for these flavonoids were also identified.We constructed a specific metabolic map for flavonoids according to their relative contents in the flowers,fruits,stems,and leaves of C.acuminate.Furthermore,the most probable genes involved in chalcone biosynthesis,flavonoid hydroxylation,methylation,and glycosylation were further mined and fished in the gene reservoir of C.acuminate according to their conserved domains and co-expression analysis.These findings enable us to acquire a better understanding of versatile flavonoid metabolism in C.acuminate.展开更多
Since alkaloids are the major active constituents of Rhizoma corydalis(RC),a convenient and accurate analytical method is needed for their identification and characterization.Here we report a method to profile the alk...Since alkaloids are the major active constituents of Rhizoma corydalis(RC),a convenient and accurate analytical method is needed for their identification and characterization.Here we report a method to profile the alkaloids in RC based on liquid chromatography-tandem quadrupole time-of-flight mass spectrometry(LC–Q-TOF-MS/MS).A total of 16 alkaloids belonging to four different classes were identified by comparison with authentic standards.The fragmentation pathway of each class of alkaloid was clarified and their differences were elucidated.Furthermore,based on an analysis of fragmentation pathways and alkaloid profiling,a rapid and accurate method for the identification of unknown alkaloids in RC is proposed.The method could also be useful for the quality control of RC.展开更多
The cereals and their products,which have been easily infected by fungi and contaminated with mycotoxins,are serious threat to both human and animals alike.And yet,detection of these unknown fungal infection and mycot...The cereals and their products,which have been easily infected by fungi and contaminated with mycotoxins,are serious threat to both human and animals alike.And yet,detection of these unknown fungal infection and mycotoxins contaminates remains a great challenge.In this work,a holistic approach based on multiple characteristic structure fragments scans and high-resolution mass spectrometry(HRMS)was proposed for discovering unknown structural analogues of mycotoxins.The structural similarity of the same class of compounds provides a direction for the discovery and identification of unknown structural analogues of mycotoxins.The following steps were carried out:the fragmentation pathways of four types of mycotoxins were elucidated through comprehensive fragment analysis.By the combination of fragmentation pathways,the multiple characteristic structure fragments were screened out,with the common fragments were obtained by Veen diagram.Finally multiple characteristic structure fragments scans were carried out to find the unknown structural analogues of mycotoxins.The approach,first proposed by us,was proved to be effective in discovering and identifying 5 structural analogues of mycotoxins in real samples.It was proved to be a simple,fast and accurate method for early detection of fungal infection and mycotoxin contaminants,even for trace amounts of chemicals in complex matrix,and is of great significance to prevent hazardous substances infection from the food supply chains worldwide.展开更多
Steroid saponins are secondary metabolites with multiple medicinal values that are found in large quantities in natural medicines,especially Vernonia amygdalina,a famous nature medicine for the treatment of tonsilliti...Steroid saponins are secondary metabolites with multiple medicinal values that are found in large quantities in natural medicines,especially Vernonia amygdalina,a famous nature medicine for the treatment of tonsillitis,diabetes,pneumonia.The current study was designed to combine molecular networking(MN)with diagnostic ions for rapid identification ofΔ^(7,9(11))stigmastane-type saponins which were theα-glucosidase inhibitory active substances in V.amygdalina.First,theα-glucosidase inhibitory activities of fiveΔ^(7,9(11))stigmastane-type steroid saponins that were previously isolated were screened,which indicated that theΔ^(7,9(11))stigmastane-type steroid saponin was one of the active constituents responsible for ameliorating diabetes.Furthermore,a strategy was proposed to identify stigmastane-type steroid saponins and verify the plausibility of derived fragmentation pathways by applying MN,MolNetEnhancer and unsupervised substructure annotation(MS2LDA).Based on this strategy,other sevenΔ^(7,9(11))stigmastane-type steroid saponins were identified from this plant.Our research provide scientific evidence for the antidiabetic potential of the steroid saponin-rich extract of V.amygdalina leaf.展开更多
基金supported by Twelfth Five-Year National Science&Technology Support Program(No.2012BA129B06)Standardization of Traditional Chinese Medicines/Indigenous drugs sponsored by Chinese Academy of Sciences(KSZD-EW-Z-004-01)
文摘The present study was designed to systematically investigate the ESI-MSn behavior of a complex 3, 7-O-glycosyl flavonol, kaempferol 3-O-α-L-[2,3-di-O-β-D-（6-E-p-coumaroyl）glucopyranosyl]-rhamnopyranosyl-7-O-α-L-rhamnopyranoside （KO） isolated from Epimedium wushanense, and to address the elimination priority among different glycosylation sites and different sugars/substituents. The direct-infusion ESI-MSn experiment of KO was performed on a hybrid LTQ-Orbitrap Velos Pro mass spectrometer in both negative and positive ion modes by three different fragmentation mechanisms （CID, HCD, and PQD）. The CID, HCD, and PQD analyses of KO exhibited remarkable discrimination in respect of the scan range, richness, and distribution of product ions through the entire spectra. KO experienced different fragmentation pathways between two ionization modes： the negative mode CID of KO eliminated the glycosyl portions （priority： 7-sugar 〉 3-substituent and terminal substituents 〉 inner sugar） and produced aglycone product ions at m/z 284.03/285.04; however, abundant sodium-adduct B32 together with subsequent ijX30 cleavages were found characteristic for the positive mode CID-MSn. The fragmentation pathways by CID for KO were proposed by analyzing the high accuracy ESI-MS＂ data. Complementary structural information of KO regarding the aglycone and glycosyl portions was obtained by analyzing the ESI-MSn data in both ionization modes. In conclusion, the LTQ-Orbitrap method facilitates highly reliable qualitative analysis of bioactive flavonoids with three alternative fragmentation modes.
文摘The impurities in ethyl-2-[[2′-cyanobiphenyl-4-yl] methyl] amino]-3-nitrobenzoate,an intermediate for synthesis of candesartan cilexiti,were detected by LC-MSn. The structural assignment of these impurities was carried out by LC-MSn using electrospray ionization source and an ion trap mass analyzer. The formation of the impurities was discussed. Also the fragmentation pathways of these compounds were studied.
基金Supported by the National Natural Science Foundation of China(No.20572061).
文摘Amino acid methyl ester phosphates were synthesized and determined by using positive-ion mode dectrospmy ionization mass spectrometry（ESIMS） in combination with multistage tandem mass spectrometry. The fragmentation pathways were investigated, and it was observed that most fragment ions contained the phosphoryl group. It was interesting to observe that the fragmentation pathways of the protonated molecule show some differences when compared with those of the sodium ion adduct. The methoxy group of amino acid methyl ester can migrate from the carbonyl group to the phosphoryl group in the sodium ion adduct.
基金supported by National Natural Science Foundation of China(81973444 and 81773875)National Key Research and Development Plan(2018YFC1707300).
文摘Background:As one of the most popular traditional Chinese medicines(TCMs)for the treatment of various liver diseases,virgate wormwood herb(Artemisia capillaris Thunb.)has a long application history in TCM practices.It has been well established that the chemical composition is responsible for the pronounced therapeutic spectrum of A.capillaris.Although they are comprehensive,the time-intensive liquid chromatography coupled to tandem mass spectrometry(LCeMS/MS)assays cannot fully satisfy the analytical measurement workload from many test samples.Direct infusion-MS/MS(DIeMS/MS)may be the optimal choice to achieve high-throughput analysis if the mass spectrometer can universally record MS2 spectra.Methods:According to the application of gas phase ion fractionation concept,the MS/MSALL program enables to gain MS2 spectrum for each nominal m/z value with a data-independent acquisition algorithm via segmenting the entire MS1 ion cohort into sequential ion pieces with 1 Da width,when sufficient measurement time is allowed by DI approach.Here,rapid clarification of the chemical composition was attempted for A.capillaris using DIeMS/MSALL.A.capillaris extract was imported directly into the electrospray ionization interface to obtain the MS/MSALL measurement.After the MS1-MS2 dataset was well organized,we focused on structural characterization through retrieving information from the available databases and literature.Results:Twenty-six compounds were found,including 12 caffeoyl quinic acid derivatives,7 flavonoids,and 7 compounds belonging to other chemical families.Among them,24 ones were structurally identified.Compared with the LCeMS/MS technique,DIeMS/MSALL has the advantages of low-costing,solvent-saving,and time-saving.Conclusions:Chemical profiling of A.capillaris extract was accomplished within 5 min by DIeMS/MSALL,and this technique can be an alternative choice for chemical profile characterization of TCMs due to its extraordinary high-throughput advantage.
基金National Natural Science Foundation of China (Grant No. 20772009)
文摘The fragmentation patterns of a series of dispirocyclopiperazinium dibromides with strong analgesic activity during positive ion electrospray ionization mass spectrometry were analyzed. The [M-Br]^＋ 2 ions showed the characteristic isotopic peaks and were assigned as the molecular ions. The loss of a 44 Dalton unit from 2 produced ion 3 [M-Br-44]^＋ and the loss of HBr from 2 formed ion 4. Besides, the carbamates 1d-1e produced extra ions [M-2Br-33]^＋. The related fragmentation mechanisms were proposed.
基金The authors wish to acknowledge the financial support provided by the Department of Science and Technology of Sichuan Province,PR China(Project No.2021ZYD0059)the National Natural Science Foundation of China(Project No.21708028)the National College Students Innovation and Entrepreneurship Training Program,PR China(Project No.201910626009).
文摘Flavonoid metabolism in Camptotheca acuminate remained an untapped area for years.A tandem MS approach was used and focused on the mining and characterizing of flavonoids in mature C.acuminate.Fifteen new flavonoids and forty-three known flavonoids,including fifteen flavone analogs,sixteen flavonol analogs,seven flavanone analogs,six chalcone analogs,four xanthone analogs,ten flavane analogs were mined and identified based on their MS/MS fragments.Fifty-three of them were firstly characterized in C.acuminate.Eight biosynthetic precursors for these flavonoids were also identified.We constructed a specific metabolic map for flavonoids according to their relative contents in the flowers,fruits,stems,and leaves of C.acuminate.Furthermore,the most probable genes involved in chalcone biosynthesis,flavonoid hydroxylation,methylation,and glycosylation were further mined and fished in the gene reservoir of C.acuminate according to their conserved domains and co-expression analysis.These findings enable us to acquire a better understanding of versatile flavonoid metabolism in C.acuminate.
基金The work was funded by the National Natural Science Foundation of China(Nos.81202950 and 81102795)National Key Project of the Scientific and Technical Supporting Programs of China(No.2012ZX10004301-608).
文摘Since alkaloids are the major active constituents of Rhizoma corydalis(RC),a convenient and accurate analytical method is needed for their identification and characterization.Here we report a method to profile the alkaloids in RC based on liquid chromatography-tandem quadrupole time-of-flight mass spectrometry(LC–Q-TOF-MS/MS).A total of 16 alkaloids belonging to four different classes were identified by comparison with authentic standards.The fragmentation pathway of each class of alkaloid was clarified and their differences were elucidated.Furthermore,based on an analysis of fragmentation pathways and alkaloid profiling,a rapid and accurate method for the identification of unknown alkaloids in RC is proposed.The method could also be useful for the quality control of RC.
基金This work was financially supported by National Key Research and Development Program of China(2018YFC1602702)National“Ten thousand Plan”Scientific and Technological Innovation Leading Talent Project(Feng ZHANG).
文摘The cereals and their products,which have been easily infected by fungi and contaminated with mycotoxins,are serious threat to both human and animals alike.And yet,detection of these unknown fungal infection and mycotoxins contaminates remains a great challenge.In this work,a holistic approach based on multiple characteristic structure fragments scans and high-resolution mass spectrometry(HRMS)was proposed for discovering unknown structural analogues of mycotoxins.The structural similarity of the same class of compounds provides a direction for the discovery and identification of unknown structural analogues of mycotoxins.The following steps were carried out:the fragmentation pathways of four types of mycotoxins were elucidated through comprehensive fragment analysis.By the combination of fragmentation pathways,the multiple characteristic structure fragments were screened out,with the common fragments were obtained by Veen diagram.Finally multiple characteristic structure fragments scans were carried out to find the unknown structural analogues of mycotoxins.The approach,first proposed by us,was proved to be effective in discovering and identifying 5 structural analogues of mycotoxins in real samples.It was proved to be a simple,fast and accurate method for early detection of fungal infection and mycotoxin contaminants,even for trace amounts of chemicals in complex matrix,and is of great significance to prevent hazardous substances infection from the food supply chains worldwide.
基金supported by the National Natural Science Foundation of China(No.81573550)。
文摘Steroid saponins are secondary metabolites with multiple medicinal values that are found in large quantities in natural medicines,especially Vernonia amygdalina,a famous nature medicine for the treatment of tonsillitis,diabetes,pneumonia.The current study was designed to combine molecular networking(MN)with diagnostic ions for rapid identification ofΔ^(7,9(11))stigmastane-type saponins which were theα-glucosidase inhibitory active substances in V.amygdalina.First,theα-glucosidase inhibitory activities of fiveΔ^(7,9(11))stigmastane-type steroid saponins that were previously isolated were screened,which indicated that theΔ^(7,9(11))stigmastane-type steroid saponin was one of the active constituents responsible for ameliorating diabetes.Furthermore,a strategy was proposed to identify stigmastane-type steroid saponins and verify the plausibility of derived fragmentation pathways by applying MN,MolNetEnhancer and unsupervised substructure annotation(MS2LDA).Based on this strategy,other sevenΔ^(7,9(11))stigmastane-type steroid saponins were identified from this plant.Our research provide scientific evidence for the antidiabetic potential of the steroid saponin-rich extract of V.amygdalina leaf.
