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The rapid and accurate authentication of traditional Chinese medicines(TCMs)has always been a key scientific and technical problem in the field of pharmaceutical analysis.Herein,a novel heating online extraction electrospray ionization mass spectrometry(H-oEESI-MS)was developed for the rapid and direct analysis of extremely complex substances without the requirement for any sample pretreatment or pre-separation steps.The overall molecular profile and fragment structure features of various herbal medicines could be completely captured within 10-15 s,with minimal sample(＜0.5 mg)and solvent consumption(＜20 μL for one sample).Furthermore,a rapid differentiation and authentication strategy for TCMs based on H-oEESI-MS was proposed,including metabolic profile characterization,characteristic marker screening and identification,and multivariate statistical analysis model validation.In an analysis of 52 batches of seven types of Aconitum medicinal materials,20 and 21 key compounds were screened out as the characteristic markers of raw and processed Aconitum herbal medicines,respectively,and the possible structures of all the characteristic markers were comprehensively identified based on Com-pound Discoverer databases.Finally,multivariate statistical analysis showed that all the different types of herbal medicines were well differentiated and identified(R2X＞0.87,R2Y＞0.91,and Q2＞0.72),which further verified the feasibility and reliability of this comprehensive strategy for the rapid authentication of different TCMs based on H-oEESI-MS.In summary,this rapid authentication strategy realized the ultra-high-throughput,low-cost,and standardized detection of various complex TCMs for the first time,thereby demonstrating wide applicability and value for the development of quality standards for TCMs.
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Complicated chemical reactions occur in the decoction of traditional Chinese medicines(TCMs) which features complex components, influencing the safety, efficacy, and quality controllability of TCMs. Therefore, it is particularly important to clarify the chemical reaction mechanism of TCMs in the decoction. This study summarized eight typical chemical reactions in the decoction of TCMs, such as substitution reaction, redox reaction, isomerization/stereoselective reaction, complexation, and supramolecular reaction. With the "toxicity attenuation and efficiency enhancement" of aconitines and other examples, this study reviewed the reactions in decoction of TCMs, which was expected to clarify the variation mechanisms of key chemical components in this process and to help guide medicine preparation and safe and rational use of medicine in clinical settings. The current main research methods for chemical reaction mechanisms of decoction of TCMs were also summed up and compared. The novel real-time analysis device of decoction system for TCMs was found to be efficient and simple without the pre-treatment of samples. This device provides a promising solution, which has great potential in quantity evaluation and control of TCMs. Moreover, it is expected to become a foundational and exemplary research tool, which can advance the research in this field.
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Medicine , Medicine, Chinese Traditional , Research DesignABSTRACT
This study focused, for the first time, on the effect of ultrasonic features on the extraction efficiency of secondary metabolites in mustard seed cake (MSC). The nematostatic potential of sonicated seed cake was examined against the second-stage juveniles (J2s) of root-knot nematode,
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Desorption electrospray ionization mass spectrometry (DESI-MS) is a newly emerging in-situ ionization mass spectrometry analysis technology. The ionization process occurs in an open ambient environment at atmospheric pressure, and has the characteristics of simple sample pretreatment, quick and sensitive analysis, and is widely used in biomedicine, pharmaceutical analysis, food safety, environmental monitoring, and material characterization. Natural medicines, such as Chinese herbal medicines, contain a variety of chemical components. Extraction, separation, identification, and in vitro and in vivo efficacy evaluation of natural medicines, especially research on active ingredients with significant efficacy, have received long-term attention. The development of DESI-MS technology provides many new opportunities for direct and rapid analysis of active ingredients in natural medicines. This article briefly introduces the principles, characteristics, influencing factors, and technical progress of DESI-MS technology, and systematically summarizes progress in the research and application of this technology to natural medicines such as Chinese herbal medicines and other plant samples with pharmacological activity. The future application prospects in this field are further presented.
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Due to numerous obstacles such as complex matrices, real-time monitoring of complex reaction systems (, medicinal herb stewing system) has always been a challenge though great values for safe and rational use of drugs. Herein, facilitated by the potential ability on the tolerance of complex matrices of extractive electrospray ionization mass spectrometry, a device was established to realize continuous sampling and real-time quantitative analysis of herb stewing system for the first time. A complete analytical strategy, including data acquisition, data mining, and data evaluation was proposed and implemented with overcoming the usual difficulties in real-time mass spectrometry quantification. The complex Fuzi (the lateral root of )-meat stewing systems were real-timely monitored in 150 min by qualitative and quantitative analysis of the nine key alkaloids accurately. The results showed that the strategy worked perfectly and the toxicity of the systems were evaluated and predicated accordingly. Stewing with trotters effectively accelerated the detoxification of Fuzi soup and reduced the overall toxicity to 68%, which was recommended to be used practically for treating rheumatic arthritis and enhancing immunity. The established strategy was versatile, simple, and accurate, which would have a wide application prospect in real-time analysis and evaluation of various complex reaction systems.
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Development of rapid analytical methods and establishment of toxic component limitation standards are of great importance in quality control of traditional Chinese medicine. Herein, an on-line extraction electrospray ionization mass spectrometry (oEESI-MS) coupled with a novel whole process integral quantification strategy was developed and applied to direct determination of nine key aconitine-type alkaloids in 20 proprietary Chinese medicines (APCMs). Multi-type dosage forms (, tablets, capsules, pills, granules, and liquid preparation) of APCM could be determined directly with excellent versatility. The strategy has the characteristics of high throughput, good tolerance of matrix interference, small amount of sample (∼0.5 mg) and reagent (∼240 μL) consumption, and short analysis time for single sample (<15 min). The results were proved to be credible by high performance liquid chromatography-mass spectrometry (LC-MS) and electrospray ionization mass spectrometry, respectively. Moreover, the limitation standard for the toxic aconitines in 20 APCMs was established based on the holistic weight toxicity (HWT) evaluation and the severally, and turned out that HWT-based toxicity evaluation results were closer to the real clinical applications. Hence, a more accurate and reliable APCM toxicity limitation was established and expected to play an important guiding role in clinics. The current study extended the power of ambient MS as a method for the direct quantification of molecules in complex samples, which is commonly required in pharmaceutical analysis, food safety control, public security, and many other disciplines.
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Objective: Using ultra-high performance liquid chromatography with diode array detection (UHPLC-DAD) and desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) to analyze 15 batches of Shaoyao Gancao Decoction (SGD) substance benchmark and lyophilized powder in order to investigate the advantages of DESI-MSI in quality control of famous classical formulas. Methods: Taking SGD as the research model, fingerprints of the substance benchmark were established by UHPLC-DAD, and the content of index components (paeoniflorin, liquiritin, glycyrrhizic acid) and the yield of dry extract were also investigated. Meanwhile, as the research carrier, the lyophilized powder corresponding to SGD was dissolved in methanol and dotted on qualitative filter paper with quantitative capillary, and fixed it on the slide to make samples. The samples were analyzed on a DESI-MSI system in positive and negative ion mode with methanol-formic acid (1 000:1, flow rate of 3 μL/min) as spray solvent, N2 as spray gas (pressure of 0.5 MPa). The scanning range was m/z 100-1 200, the spatial resolution was 300 μm, the ion source temperature was 120 ℃. Results: DESI-MSI can detect not only the index components of paeoniflorin, liquiritin, glycyrrhizic acid, but also the common peaks of albiflorin. At the same time, DESI-MSI could detect 11 other components from Glycyrrhizae Radix et Rhizoma and Paeoniae Radix Alba, such as licoricesaponin G2, licoricesaponin J2, gallic acid, citric acid, p-hydroxybenzoic acid, and present their relative content visually. The qualitative analysis ability of DESI-MSI was much better than UHPLC-DAD. Conclusion: DESI-MSI can be used as the quality control method for substance benchmark and lyophilized powder and dispensing granules of classical famous formulas with advantages of high sensitivity, strong analytical ability, no complex sample pretreatment, qualitative and relative content analysis of complex samples without reference substance.
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Background: A new ι-carrageenase-producing strain was screened from mangroves and authenticated as Pseudoalteromonas carrageenovora ASY5 in our laboratory. The potential application of this new strain was evaluated. Results: Medium compositions and culturing conditions in shaking flask fermentation were firstly optimized by single-factor experiment. ι-Carrageenase activity increased from 0.34 U/mL to 1.08 U/mL after test optimization. Optimal fermentation conditions were 20°C, pH 7.0, incubation time of 40 h, 15 g/L NaCl, 1.5% (w/v) yeast extract as nitrogen source, and 0.9% (w/v) ι-carrageenan as carbon source. Then, the crude ι-carrageenase was characterized. The optimum temperature and pH of the ι-carrageenase were 40°C and 8.0, respectively. The enzymatic activity at 3540°C for 45 min retained more than 40% of the maximum activity. Meanwhile, The ι-carrageenase was inhibited by the addition of 1 mmol/L Cd2+ and Fe3+ but increased by the addition of 1 mmol/L Ag+, Ba2+, Ca2+, Co2+, Mn2+, Zn2+, Fe2+, and Al3+. The structure of oligosaccharides derived from ι-carrageenan was detected using electrospray ionization mass spectrometry (ESI-MS). The ι-carrageenase degraded ι-carrageenan, yielding disaccharides and tetrasaccharides as main products. Conclusions: The discovery and study of new ι-carrageenases are beneficial not only for the production of ι-carrageenan oligosaccharides but also for the further utilization in industrial production.
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Bacterial Proteins/metabolism , Pseudoalteromonas/enzymology , Glycoside Hydrolases/metabolism , Oligosaccharides/biosynthesis , Temperature , Carbon/metabolism , Carrageenan/biosynthesis , Spectrometry, Mass, Electrospray Ionization , Fermentation , Hydrogen-Ion Concentration , Hydrolysis , Nitrogen/metabolismABSTRACT
The non-covalent interactions between 18-crown-6 (18c6) and 20 common types of protonated amino acids were explored by electrospray ionization mass spectrometry (ESI-MS).The mass spectra showed the formation of 1:1 stoichiometric non-covalent complexes between 18c6 and amino acids.The calibration curves and linear equations for the complexes of L-Phe,L-Tyr,L-Lys and L-Asp with 18c6 were established by mass spectrometric titration and used as reference values for competitive ESI-MS.Through competitive equilibrium,the binding constants for the complexes of 18c6 with other L-amino acids and their D-isomers were derived.It was found,as a general trend,lgKa for the complexes of 18c6 with the basic amino acid and the amino acid with alkyl side chain were larger than other complexes,and among the amino acids with alkyl side chain,Gly and Ala exhibited greater 18c6 binding affinities.As for Ser and Thr,the intramolecular hydrogen bond between the nitrogen atom from terminal NH2and the oxygen atom from carboxyl may impede their protonated amino-group to attack the 18c6.Furthermore,Gln and Asn exhibited lower 18c6 binding affinities probably due to effects of electron-withdrawing group of acylamide.Finally,the chiral selectivity of 18c6 for 19 L-,or D-amino acids was measured by ESI-MS,indicating 18c6 could only recognize some neutral amino acid isomers.
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Objective Chiral recognition for the glimepiride and glimepiride-cis-isomer by applying three amino acid (D-Lysine,L-Glutamine and L-Tyrosine) as chiral probes based on electrospray ionization mass spectrometry (ESI-MS) was achieved.Methods glimepiride/glimepiride-cis-isomer solutions were mixed with three amino acid solutions.The complex was extracted by ESI-MS and then the fragmentation abundance was investigated applying collision induced dissociation (CID) by MS/MS,which is the basis of chiral recognition for glimepiride and glimepiride-cis-isomer.Results Chiral recognition effect was achieved with the recognition rate (R) 1.61,2.92 and 2.17 for D-Lysine,L-Glutamine and L-Tyrosine respectively.Conclusion 3 kinds ofchiral amino acids were used as probes to distinguish between stereoisomers,and rapid identification of glimepiride and glimepiride cis isomer by mass spectrometry come true for the first time.
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Matrix_assisted laser desorption ionization_time of flight tandem mass spectrometry ( MALDI_TOF/TOF MS) and electrospray ionization_quadrupole_time of flight mass spectrometry ( ESI_Q_TOF MS) were used to confirm the structure of cyclic lipopeptide daptomycin fastly. First, the relative molecular weight 1916. 7107 of daptomycin was measured by ESI with error 0. 0007. The sample’s doubly charged peak m/z 809. 848 was selected as precursor ion for ESI_MS/MS analysis, and the exocyclic amino acid sequence C9 H19 CO_Trp_Asn_Asp was successfully matched. Second, the experimental conditions of cleaving daptomycin by lithium hydroxide ( LiOH) were optimized and the ring_opened process was monitored by MALDI_TOF/TOF MS. After obtaining ring_opened product with purity of above 95%, the MS/MS measurements by MALDI and ESI were carried out. The b+and y+of ring_opened product were completely matched, which confirmed the amino acid sequence of daptomycin. Finally, ESI_MS/MS conditions of ring_opened product were further optimized to obtain more low mass fragment ions for analyzing the structure of fatty acid chain and the cleavage pattern of fat chain in mass spectrometry was proposed. The method was fast, convenient, accurate and reliable for identifying cyclic lipopeptide compounds.
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Acylcarnitine profiling by electrospray ionization tandem mass spectrometry (ESI-MS/MS) is a potent tool for the diagnosis and screening of fatty acid oxidation and organic acid disorders. Few studies have analyzed free carnitine and acylcarnitines in dried blood spots (DBS) of umbilical cord blood (CB) and the postnatal changes in the concentrations of these analytes. We have investigated these metabolites in healthy exclusively breastfed neonates and examined possible effects of birth weight and gestational age. DBS of CB were collected from 162 adequate for gestational age neonates. Paired DBS of heel-prick blood were collected 4-8 days after birth from 106 of these neonates, the majority exclusively breastfed. Methanol extracts of DBS with deuterium-labeled internal standards were derivatized before analysis by ESI-MS/MS. Most of the analytes were measured using a full-scan method. The levels of the major long-chain acylcarnitines, palmitoylcarnitine, stearoylcarnitine, and oleoylcarnitine, increased by 27, 12, and 109%, respectively, in the first week of life. Free carnitine and acetylcarnitine had a modest increase: 8 and 11%, respectively. Propionylcarnitine presented a different behavior, decreasing 9% during the period. The correlations between birth weight or gestational age and the concentrations of the analytes in DBS were weak (r £ 0.20) or nonsignificant. Adaptation to breast milk as the sole source of nutrients can explain the increase of these metabolites along the early neonatal period. Acylcarnitine profiling in CB should have a role in the early detection of metabolic disorders in high-risk neonates.
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Female , Humans , Infant, Newborn , Male , Breast Feeding , Carnitine/analogs & derivatives , Fetal Blood/chemistry , Neonatal Screening , Tandem Mass Spectrometry/methods , Brazil , Carnitine/blood , Dried Blood Spot Testing/methods , Fatty Acids/metabolism , Statistics, Nonparametric , Spectrometry, Mass, Electrospray Ionization/methodsABSTRACT
Euphorbia lathyris (Caper spurge) is a toxic and potent Chinese materia medica (T/PCMM).This study sought a method for identifying five diterpenoids (Euphorbia factors L1-L3,L7a and L8) with the spectra of UV and mass,quantifying three diterpenoids L1,L2,and L8 in crude extracts of unprocessed and processed E.lathyris seeds by liquid chromatography/electrospray ionization mass spectrometry (LC-ESI-MS).The analysis was achieved on an Agilent Eclipse XDB-C18 column (4.6 mm × 150 mm i.d.,5 μm) with an isocratic elution with a mobile phase consisting of water and acetonitrile at a flow rate of 0.25 mL/min at column temperature of 30 ℃ and UV detection was set at 272 nm.An ESI source was used with a positive ionization mode.The calibration curve was linear in the ranges of 9.9-79 μg/mL for Euphorbia factor L1,3.8-30.5 μg/mL for Euphorbia factor L2,and 1.0-20.6 μg/mL for Euphorbia factor L8.The average recoveries (n=6) of three diterpenoids were 98.39％,91.10％ and 96.94％,respectively,with RSD of 2.5％,2.4％ and 2.1％,respectively.The contents of the three diterpenoids in processed E.lathyris seeds were 3.435,1.367 and 0.286 mg/g,respectively,which decreased more sharply than those in unprocessed E.lathyris seeds which were 4.915,1.944 and 0.425 mg/g,respectively.The method is simple,accurate,reliable and reproducible,and it can be applied to control the quality of unprocessed and processed E.lathyris seeds.
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Due to the complexity of proteome samples, comprehensive analysis to characterize all proteins was still not possible with present methodologies. It has been shown that replicate runs could increase the number of identified) proteins. However, the redundancy of protein identifications was high. High-abundant peptides tended to be analyzed repeatedly in different runs. To reduce the redundancy and improve the efficiency of identification), we studied the MS/MS acquisition method of linear ion trap Fourier transform ion cyclotron resonance)-mass spectrometry(LTQ-FT) and an acquisition strategy based on exclusion of precursor ions was developed). It proved that the strategy could extremely reduce the redundancy of MS/MS acquisition and improve) the efficiency of protein identifications.
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To identify acute renal allograft rejection biomarkers in human serum, two-dimensional differential in-gel electrophoresis (2-D DIGE) and reversed phase high-performance liquid chromatog-raphy (RP-HPLC) followed by electrospray ionization mass spectrometry (ESI-MS) were used. Serum samples from renal allograft patients and normal volunteers were divided into three groups: acute rejec-tion (AR), stable renal function (SRF) and normal volunteer (N). Serum samples were firstly processed using Multiple Affinity Removal Column to selectively remove the highest abundance proteins. Differ-entially expressed proteins were analyzed using 2-D DIGE. These differential protein spots were ex-cised, digested by trypsin, and identified by RP-HPLC-ESI/MS. Twenty-two differentially expressed proteins were identified in serum from AR group. These proteins included complement C9 precursor,apolipoprotein A-Ⅳ precursor, vitamin D-binding protein precursor, beta-2-glycoprotein 1 precursor,etc. Vitamin D-binding protein, one of these proteins, was confirmed by ELISA in the independent set of serum samples. In conclusion, the differentially expressed proteins as serum biomarker candidates may provide the basis of acute rejection noninvasive diagnosis. Confirmed vitamin D-binding protein may be one of serum biomarkers of acute rejection. Furthermore, it may provide great insights into un-derstanding the mechanisms and potential treatment strategy of acute rejection.
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A method was established for identifying the chemical components of a traditional Chinese medicinal formula Baihe Zhimu Tang and its single herbs by combining high performance liquid chromatography and electrospray ionization mass spectrometry(HPLC-ESI-MS). The molecular ions of compounds in both negative and positive modes were observed for molecule mass information, and the potential structures were identified by attentive studying on the mass spectra of compounds and comparing with Reference data and some of standards. The results show that in MS detection, saponins in Baihe Zhimu Tang and its single herbs are easily to become positive ions in the electrospray ionization procedure, and they have strong responses, but the mass spectrometric signals of flavonoids and phenolic glucosides are week. 38 compounds in Baihe Zhimu Tang including 3 flavonoids, 4 phenolic glucosides and 31 saponins were identified through analyzing and comparing the total ion chromatograms(TIC) and mass spectra of Baihe Zhimu Tang and its single herbs. This method has the advantages of simple operation, rapid measurement and it is a powerful tool for identification of chemical components in Baihe Zhimu Tang.
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Mammal metallothionein(MT) folds into two separate domains that exhibit different structure and metal binding propertity independently, the study of the strategy of metal ions binding with MT would give better understanding of their exact biological functional mechanisms. In this study, a method using eletrospray ionization mass spectrometry (ESI-MS) phase liquid chromatography and identified by ESI-MS. Different amounts of Cd or Cu were then added in MT-2a samples and ESI-MS was employed to determine the mass difference of MT in different samples. The results Cd2+4S11; while Cd is attached in separate binding sites for the formation of Cd2+3S9 cluster, which intermediately formed with five and six Cd ions were detected. For the Cuprous ions, it prefers to cooperatively bind in β-domain with the form of Cu4-MTβ. The binding form in β-domain would convert from Cu4 into more Cu binding form with the addition of Cu. When high concentration of Cu was added in samples, the result suggested that
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The Nano ultra-high performance liquid chromatography-electrospray ionization mass spectrometry tandem mass spectrometry(UPLC-ESI-MS/MS) was used to characterize the primary protein. Samples were digested by trypsin, followed by liquid chromatography-tandem mass spectrometry analysis and database search. Five peptides matched with tumor necrosis factor receptor and seven peptides matched with human IgG1 fragment of the Fc. Further analysis demonstrated that seven peptides all matched with the IgG1 Fc but only partly peptides matched with the other subtypes. RhTNFR:Fc is fused by IgG1 Fc but not other subtypes.
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Objective To synthesize aristolochic acid Ⅰ(AAⅠ)-DNA adduct in vitro and to develop a method for the characterization of the adduct. Methods Aristolochic acid (AA) was incubated with 2′-Deoxyadenosine 5′-monophosphate in vitro using either enzymatic activation (by xanthine oxidase) or chemical activation (by zinc) to synthesize AAⅠ-DNA adduct. The AAⅠ-DNA adduct was characterized by the liquid chromatography electrospray ionization/tandem mass spectrometry (LC-ESI-MS/MS). Results AAⅠ-DNA adduct was prepared by two activation methods. Full scan spectra were obtained in the negative ion mode and the quasi-molecular ion peak was m/z 621. Analysis by electrospray ionization/tandem mass spectrometry (ESI-MS/MS) provided useful structural information about AAⅠ-DNA adduct. Conclusion AAⅠ can bind covalently to the exocyclic amino group of purine nucleotides to form AAⅠ-DNA adduct. LC/MS/MS is a practical tool to detect AAⅠ-DNA adduct.
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Aim To establish an analytical method for determination of guanfu base I (GFI) concentration in plasma and investigate its pharmacokinetics in rats. Methods Rats were given a 20 mg?kg~-1 dose intravenously. Blood samples were collected at various times after iv administration. The plasma concentration of GFI was determined by LC-MS. Pharmacokinetic parameters were calculated by 3p97 program.Results The method was linear in the 0.05～20 mg?L~-1 concentration range (r=~0.999 4 ). The recovery of guanfu base I was more than 80%.The intraday and interday precision, expressed as the relative standard deviation (RSD), was generally good (