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1.
Environ Sci Pollut Res Int ; 30(50): 108694-108705, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37751004

RESUMO

Staphylococcal enterotoxins (SEs) secreted by Staphylococcus aureus (S. aureus) can cause foodborne disease, nausea, vomiting and diarrhea, and even death. Regulation of SE expression is related to accessory gene regulators (Agr). It is important to reveal which environmental factors influence regulation of SE expression to prevent SE food poisoning outbreak. Hence, natural environmental factors which may have an impact on SE expression were selected, such as temperature, food types, strains, and competing strains. Seven strains of S. aureus carrying different SE genes were collected from the Chinese Academy of Inspection and Quarantine (CAIQ) strain bank for study. Strains were cultured with different conditions. Temperature was 8 °C, 22 °C, and 30 °C. Food type was milk powder and nutrient broth. Competing strains were Vibrio parahaemolyticus (V. parahaemolyticus), Escherichia coli (E. coli), and Bacillus cereus (B. cereus). The expression culture solution was pretreated by centrifugation, then determined by using SDS-PAGE, and distinguished SEs apart from each other by HPLC-ESI-TOF. There are 168 samples collected from SE expression culture; the result of SDS-PAGE suggests 23 samples were positive for SEs, and the other 145 samples were negative for SEs. The result of HPLC-ESI-TOF suggests that SEs with similar molecular weight can be distinguished in terms of m/z. The most important factor contributing to regulate expression of SEs was estimated by logistic regressive analysis. The result shows that McFadden R2 is 0.213; p value is 0.000 (p < 0.05); this result illustrates that the model is valid and meaningful. Strains, food types, temperature, and competing strands can explain the 21% change in SE expression. Temperature (z = 3.029, p = 0.002 < 0.01), strains (z = - 3.132, p = 0.002 < 0.01), and food types (z = - 2.415, p = 0.016 < 0.05) have significant impact on SE expression, and the competing strains (z = 1.230, p = 0.219 > 0.05) have no impact on the SE expression. More important impact on SE expression was estimated by OR value; the result shows that strength of temperature influencing on SE expression is bigger than strains and food types in terms of values of OR, temperature (OR = 2.862), strains (OR = 0.641), and food types (OR = 0.561); consequently, temperature is a key factor for stimulating SE expression and had high expression at 30 °C. Therefore, food easily contaminated with S. aureus should be monitored intensively at early and late summer, when proper temperature for expressing SEs may result in S. aureus food poisoning prevalence.


Assuntos
Intoxicação Alimentar Estafilocócica , Infecções Estafilocócicas , Humanos , Enterotoxinas/análise , Staphylococcus aureus/genética , Escherichia coli , Intoxicação Alimentar Estafilocócica/epidemiologia , Microbiologia de Alimentos
2.
Artigo em Inglês | MEDLINE | ID: mdl-34626904

RESUMO

The quality control of Chinese herbal medicines (CHM) is a key concern on the modernization and globalization. However, it is still a difficult task due to its multi-component, multi-target, multi-pathways. This study aims to provide a novel and comprehensive strategy for quality control in complex Chinese medicines (CHM) formulas by UHPLC-Q-Orbitrap HRMS and UHPLC-MS/MS combined with network pharmacology analysis. Tangshen formula (TSF) was used as an example for complex CHM formulas. The UHPLC-Q-Orbitrap HRMS was firstly applied to identify or tentatively assign 85 compounds in TSF. Subsequently, key active compounds for TSF treating diabetic nephropathy (DN) were chose by chemical-target-pathways network in network pharmacology. The results showed that 13 key bioactive compounds against DN including naringin, daidzein, genistein, formononetin, chlorogenic acid, aloe-emodin, nobiletin, tangeritin, ginsenoside Rg1, hesperetin, hesperidin, rhein, and limonin with three high topological features in chemical-target-pathways network were selected as Q-markers for quality control of TSF. Finally, the UHPLC-MS/MS was performed to simultaneously determine the concentrations of 13 Q-markers. And their concentrations were ranged from 11.57 to 3 788 µg·g-1. It suggested that many key bioactive compounds not only have high contents but also have wide range contents for the quality of complex CHM formulas. This study should be helpful to guide the selection of the Q-markers and provide new strategy for quality control of complex CHM formulas.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/análise , Medicamentos de Ervas Chinesas/normas , Espectrometria de Massas em Tandem/métodos , Limite de Detecção , Modelos Lineares , Farmacologia em Rede , Controle de Qualidade , Reprodutibilidade dos Testes
3.
J Transl Int Med ; 9(2): 98-113, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34497749

RESUMO

BACKGROUND AND OBJECTIVE: HuangZhi YiShen Capsule (HZYS) is a Chinese patent herbal drug that protects kidney function in diabetic kidney disease (DKD) patients. However, the pharmacologic mechanisms of HZYS remain unclear. This study would use network pharmacology to explore the pharmacologic mechanisms of HZYS. METHODS: Chemical constituents of HZYS were obtained through the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) and literature search. Potential targets of HZYS were identified by using the TCMSP and the SwissTarget Prediction databases. DKD-related target genes were collected by using the Online Mendelian Inheritance in Man, Therapeutic Target Database, GeneCards, DisGeNET, and Drugbank databases. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were carried out to further explore the mechanisms of HZYS in treating DKD. Molecular docking was conducted to verify the potential interactions between the prime compounds and the hub genes. RESULTS: 179 active compounds and 620 target genes were obtained, and 571 common targets were considered potential therapeutic targets. The top 10 main active compounds of HZYS were heparin, quercetin, kaempferol, luteolin, methyl14-methylpentadecanoate, methyl (Z)-11-hexadecenoate, 17-hydroxycorticosterone, 4-pregnene-17α, 20ß, 21-triol-3, 11-dione, wogonin, and hydroxyecdysone. Hub signaling pathways by which HZYS treating DKD were PI3K-Akt, MAPK, AGE-RAGE in diabetic complications, TNF, and apoptosis. The top 10 target genes associated with these pathways were IL6, MAPK1, AKT1, RELA, BCL2, JUN, MAPK3, MAP2K1, CASP3, and TNF. Quercetin and Luteolin were verified to have good binding capability with the hub potential targets IL6, MAPK1, AKT1 through molecular docking. CONCLUSION: HZYS appeared to treat DKD by regulating the inflammatory, oxidative stress, apoptotic, and fibrosis signaling pathways. This study provided a novel perspective for further research of HZYS.

4.
J Diabetes Res ; 2020: 2421631, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33274236

RESUMO

BACKGROUND: Diabetic kidney disease (DKD) poses a major public-health burden globally. Tripterygium wilfordii Hook F (TwHF) is a widely employed herbal medicine in decreasing albuminuria among diabetic patients. However, a holistic network pharmacology strategy to investigate the active components and therapeutic mechanism underlying DKD is still unavailable. METHODS: We collected TwHF ingredients and their targets by traditional Chinese Medicine databases (TCMSP). Then, we obtained DKD targets from GeneCards and OMIM and collected and analyzed TwHF-DKD common targets using the STRING database. Protein-protein interaction (PPI) network was established by Cytoscape and analyzed by MCODE plugin to get clusters. In addition, the cytoHubba software was used to identify hub genes. Finally, all the targets of clusters were subjected for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses via DAVID. RESULTS: A total of 51 active ingredients in TwHF were identified and hit by 88 potential targets related to DKD. Compounds correspond to more targets include kaempferol, beta-sitosterol, stigmasterol, and Triptoditerpenic acid B, which appeared to be high-potential compounds. Genes with higher degree including VEGFA, PTGS2, JUN, MAPK8, and HSP90AA1 are hub genes of TwHF against DKD, which are involved in inflammation, insulin resistance, and lipid homeostasis. Kaempferol and VEGFA were represented as the uppermost active ingredient and core gene of TwHF in treating DKD, respectively. DAVID results indicated that TwHF may play a role in treating DKD through AGE-RAGE signaling pathway, IL-17 signaling pathway, TNF signaling pathway, insulin resistance, and calcium signaling pathway (P < 0.05). CONCLUSION: Kaempferol and VEGFA were represented as the uppermost active ingredient and core gene of TwHF in treating DKD, respectively. The key mechanisms of TwHF against DKD might be involved in the reduction of renal inflammation by downregulating VEGFA.


Assuntos
Nefropatias Diabéticas/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Fitoterapia , Tripterygium , Ciclo-Oxigenase 2/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Bases de Dados Genéticas , Bases de Dados de Produtos Farmacêuticos , Diterpenos/farmacologia , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/uso terapêutico , Ontologia Genética , Proteínas de Choque Térmico HSP90/efeitos dos fármacos , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Quempferóis/farmacologia , Rim/efeitos dos fármacos , Proteína Quinase 8 Ativada por Mitógeno/efeitos dos fármacos , Proteína Quinase 8 Ativada por Mitógeno/genética , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Fenantrenos/farmacologia , Mapas de Interação de Proteínas , Proteínas Proto-Oncogênicas c-jun/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-jun/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Sitosteroides/farmacologia , Estigmasterol/farmacologia , Fator A de Crescimento do Endotélio Vascular/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
5.
J Diabetes Res ; 2020: 3634974, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33015191

RESUMO

Tangshen Formula (TSF) is a Chinese Medicine formula that has been reported to alleviate proteinuria and protect renal function in humans and animals with diabetic kidney disease (DKD). However, little is known about its mechanism in improving proteinuria. The dysregulation of podocyte cell-matrix adhesion has been demonstrated to play an important role in the pathogenesis and progression of proteinuric kidney diseases including DKD. In the present study, the underlying protective mechanism of TSF on podocytes was investigated using the murine model of type 2 DKD db/db mice in vivo and advanced glycation end products (AGEs)-stimulated primary mice podocytes in vitro. Results revealed that TSF treatment could significantly mitigate reduction of podocyte numbers and foot process effacement, reduce proteinuria, and protect renal function in db/db mice. There was a significant increase in expression of transient receptor potential canonical channel 6 (TRPC6) and a decrease in expression of talin1 in podocytes of db/db mice. The results of AGEs-stimulated primary mice podocytes showed increased cell migration and actin-cytoskeleton rearrangement. Moreover, primary mice podocytes stimulated by AGEs displayed an increase in TRPC6-dependent Ca2+ influx, a loss of talin1, and translocation of nuclear factor of activated T cell (NFATC) 2. These dysregulations in mice primary podocytes stimulated by AGEs could be significantly attenuated after TSF treatment. 1-Oleoyl-2-acetyl-sn-glycerol (OAG), a TRPC6 agonist, blocked the protective role of TSF on podocyte cell-matrix adherence. In conclusion, TSF could protect podocytes from injury and reduce proteinuria in DKD, which may be mediated by the regulation of the TRPC6/Talin1 pathway in podocytes.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Glomérulos Renais/metabolismo , Podócitos/metabolismo , Canal de Cátion TRPC6/genética , Talina/genética , Actinas/metabolismo , Animais , Adesão Celular , Movimento Celular , Sobrevivência Celular , Citoesqueleto/metabolismo , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 2/complicações , Progressão da Doença , Humanos , Nefropatias/metabolismo , Masculino , Medicina Tradicional Chinesa , Camundongos , Camundongos Endogâmicos C57BL , Proteinúria/tratamento farmacológico , Cicatrização
6.
J Sep Sci ; 43(19): 3719-3734, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32725879

RESUMO

An analytical method for the determination of six emerging derivatives or metabolites together with 25 common macrolides antibiotics in milk by ultra-performance liquid chromatography quadrupole/electrostaticfield orbitrap mass spectrometry was established. The samples were purified with optimized Quick, Easy, Cheap, Effective, Rugged, Safe methods. The amounts of primary-secondary amine, C18, and sodium acetate adsorbent materials were optimized by response surface method to obtain the best purification effect. The chromatographic separation was carried out using the XBridge-C18 (2.1 × 100 mm, 3.5 µm, Waters) column with mobile phase of acetonitrile with 0.1% v/v formic acid-water solutions (containing 10 mmol/L ammonium acetate), separated by gradient elution. The instrument was operated in the detection mode of electrospray positive and negative ions with Full MS/data dependent MS2 acquisition mode detection, external standard method was used for quantitative analysis. The limits of detection and limits of quantitation of 31 compounds were 0.1-0.5 µg/L and 0.5-2.0 µg/L, respectively. A total of 31 compounds performed a good linearity in the range of 1 to 200 µg/L, and the correlation coefficient was greater than 0.990. The spiked recoveries in milk samples were 81.07-110.1% and the relative standard deviation was less than 5.1%. The method was successful applied to actual sample testing in the market.


Assuntos
Antibacterianos/análise , Cromatografia Líquida/métodos , Macrolídeos/análise , Leite/química , Animais , Resíduos de Drogas/análise , Contaminação de Alimentos/análise , Limite de Detecção , Espectrometria de Massas em Tandem/métodos
7.
Artigo em Inglês | MEDLINE | ID: mdl-32305709

RESUMO

Isoflavonoid phytoestrogens, referred as "dietary estrogens" are widely distributed in the plant kingdom. Formononetin, biochanin A and their active metabolites daidzein and genistein are known to be the most potent among other isoflavonoid phytoestrogens. Thus there is a growing need to determine accurately their concentration in different biological fluids. In the present work, a sensitive analytical method was developed for the quantitative determination of these compounds in human breast milk, saliva and urine. The glycoside conjugates of these compounds were enzymatically hydrolysis prior to salting-out assisted liquid-liquid extraction. Quantitative analysis was done by ultra high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. The obtained results showed high correlation coefficients (r2 > 0.998) for the linear range established for formononetine, biochanin A, daidzein and genistein. The limits of detection (LODs) and low limits of quantitation (LLOQs) were in the ranges of 0.05-1.0 ng/mL and 1.0-4.0 ng/mL for all analytes in human biological fluids, respectively. The average recoveries ranged from 83.29% to 115.24% for the analytes with relative standard deviation (n = 5) values from 1.84% to 9.75% in samples. Both intra-day and inter-day precisions and accuracy were found to be within 12.53% and ± 12.92% respectively. Under different conditions of stability, the concentrations for four isoflavonoid phytoestrogens deviated within ±12.87% of norminal values. The developed method was successfully validated and applied to human breast milk, saliva and urine. The average concentrations of daidzein and genistein found in breast milk, saliva and urine samples ranged from 0 to 104.2 µg/kg, 18.17 to 786.0 µg/kg, 0 to 10974 µg/kg, respectively. Their presence in breast milk samples shows exposure of breast-fed baby to isoflavones. It also allows for the rapid screening of human biological fluids when testing for formononetin, biochanin A, daidzein and genistein production status in human.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Genisteína/química , Isoflavonas/química , Isoflavonas/isolamento & purificação , Extração Líquido-Líquido/métodos , Leite Humano/química , Saliva/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Adulto , Feminino , Genisteína/análise , Genisteína/isolamento & purificação , Genisteína/metabolismo , Genisteína/urina , Humanos , Isoflavonas/análise , Isoflavonas/metabolismo , Isoflavonas/urina , Limite de Detecção , Saliva/metabolismo , Urina/química
8.
J Sep Sci ; 43(7): 1372-1381, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31944578

RESUMO

A novel, simple, and sensitive method has been developed for simultaneous determination of 14 heterocyclic aromatic amines in meat product using solid-phase extraction combined with ultrahigh-performance supercritical fluid chromatography coupled to tandem quadrupole mass spectrometry. The analytes could be separated within 7 min and identified using their retention times and mass. The developed method was validated based on the linearity, limits of quantification, precision, and accuracy. The recovery ranged from 52.3 to 97.5% with an acceptable standard deviation, which is not higher than 6%. The limits of quantitation ranged from 0.03 to 0.17 µg/kg. The selectivity and sensitivity were satisfactory in multiple reaction monitoring mode. The method was applied to commercial meat products, and the results demonstrated that the novel method has potential for the analysis of the targets in food matrices. This is the first work reporting the simultaneous quantification of 14 heterocyclic aromatic amines by means of ultrahigh-performance supercritical fluid chromatography coupled to tandem quadrupole mass spectrometry.


Assuntos
Aminas/análise , Compostos Heterocíclicos/análise , Hidrocarbonetos Aromáticos/análise , Produtos da Carne/análise , Cromatografia com Fluido Supercrítico , Espectrometria de Massas , Estrutura Molecular , Extração em Fase Sólida
9.
J Chromatogr A ; 1606: 460385, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31351592

RESUMO

Isoflavones are phenolic phytoestrogens due to their structural similarity to estradiol, so they usually serve as active component for quality control of traditional Chinese medicines (TCMs) rich in isoflavones. However, TCMs contains various kinds of similar isoflavones, especially isomers, which to a significant extent hinders accurate analysis of isoflavones in TCMs. Here, we present a novel analytical strategy for quality control of TCMs rich in isoflavones using ultra-high performance supercritical fluid chromatography coupled to photodiode array detection (UHPSFC-PDA) and tandem mass spectrometry (UHPSFC-MS/MS). Both chromatography and mass spectrometry parameters were optimized in order to develop an accurate, rapid, sensitive method for quantification of isoflavones. The reproducibility of quantitative analysis of multi-components by single marker (QAMS) using UHPSFC-PDA was discussed in terms of mobile phase gradient, temperature and backpressure for the first time. An analytical method for the analysis of isoflavones using UHPSFC-MS/MS was developed for the first time, and the established method was successfully applied to quantify isoflavones in three species of Radix Puerariae. The study showed Radix Pueraria Peduncularis contained higher amounts of isoflavones than Radix Puerariae Thomsonii, and it is worth noting that Radix Pueraria Peduncularis was often overlooked by researchers. It took less than 8 min with the current method and the limit of detection was not more than 0.05 ng/ml, which was definitely sufficient for anlysis of various samples from TCMs without enrichment.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia com Fluido Supercrítico/métodos , Isoflavonas/análise , Medicina Tradicional Chinesa , Pueraria/química , Isoflavonas/química , Isomerismo , Modelos Lineares , Pressão , Análise de Componente Principal , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem , Temperatura
10.
Molecules ; 23(6)2018 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-29921801

RESUMO

Vitamins are a class of essential nutrients in the body; thus, they play important roles in human health. The chemicals are involved in many physiological functions and both their lack and excess can put health at risk. Therefore, the establishment of methods for monitoring vitamin concentrations in different matrices is necessary. In this review, an updated overview of the main pretreatments and determination methods that have been used since 2010 is given. Ultrasonic assisted extraction, liquid⁻liquid extraction, solid phase extraction and dispersive liquid⁻liquid microextraction are the most common pretreatment methods, while the determination methods involve chromatography methods, electrophoretic methods, microbiological assays, immunoassays, biosensors and several other methods. Different pretreatments and determination methods are discussed.


Assuntos
Extração Líquido-Líquido/métodos , Ondas Ultrassônicas , Vitaminas/análise , Vitaminas/isolamento & purificação , Humanos
11.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1061-1062: 411-420, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28806686

RESUMO

A novel analytical method was developed and validated for simultaneous analysis of 16 macrolide antibiotics and 4 metabolites in milk. A modified quick, easy, cheap, effective, rugged, and safe extraction method (QuEChERS) optimized by response surface methodology (RSM) was used for sample preparation. All the drugs were subsequently separated and detected by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), using roxithromycin as internal standards for maximum accuracy and precision. The method was validated following the guidelines specified in Commission Decision 2002/657/EC. The recoveries of all the analytes were in the range of 62.27%-115.28%. Most macrolide antibiotics and metabolites could be detected in the concentration of 1-100ng/mL with good correlation coefficient (r2>0.998). The LODs and LOQs of all analytes were in the range of 0.30-0.85µg/kg and 1.1-4.0µg/kg, respectively. The intra-day and inter-day precision were lower than 10% and 15%, respectively. The developed method has been successfully applied to screen these compounds in different milk products.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas/análise , Macrolídeos/análise , Leite/química , Espectrometria de Massas em Tandem/métodos , Animais , Resíduos de Drogas/química , Resíduos de Drogas/isolamento & purificação , Limite de Detecção , Modelos Lineares , Macrolídeos/química , Macrolídeos/isolamento & purificação , Reprodutibilidade dos Testes
12.
Environ Sci Pollut Res Int ; 24(23): 19375-19385, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28674954

RESUMO

Staphylococcal enterotoxin A (SEA) was the major virulence factor of Staphylococcus aureus and a biomarker of S. aureus. To establish a fast, low cost, high accuracy, reliable, and simple method for detecting S. aureus, SEA was analyzed by HPLC-ESI-TOF. SEA was not yet commercially available in universal, so SEA was prepared before it was analyzed by HPLC-ESI-TOF. The result showed that high purified SEA was successfully prepared and SEA has normal distribution in mass spectra. A large amount of recombinant SEA (rSEA) was obtained by engineering technology and was purified by Ni affinity chromatography column, and the expression and purity of rSEA and SEA were analyzed by SDS-PAGE. The factors effected on ionization of SEA were studied, and the qualitative analysis of SEA by HPLC-ESI-TOF. The result showed that large amount of SEs expressed within a short time at 28 °C or thereabouts, and there was no impurity bands in electrophorogram after rSEA was purified by Ni affinity chromatography column. In addition, the SEA which had homologous AA sequence with wild SEA was made by rSEA. The retention of SEA in column and ionization of SEA in ESI-TOF were studied for qualitative analysis of S. aureus. The result showed that the content of formic acid in mobile phase was an important factor for ionization of SEs in ESI-TOF. And the result provided theoretical foundation for qualitative detection of S. aureus. [SEs + nH+ + mNH4+] n+m+ was shown on ESI-TOF spectra when SEA was detected by ESI-TOF in positive ion mode, and the numerical value of n+m was less than or equal to the number of basic amino acids in SEs. This method was applied to determine SEA in water samples preliminarily, and the detection limit of SEA in spiked water sample was 3 mg/kg. The limit of detection of 3 mg/kg was low sensitivity for low molecular weight matters, but it was high sensitivity for SEA which had a high molecular weight of 27 kDa. Of SEA, 3 mg/kg was equivalent to 10-4 mmol/kg of SEA. This study can provide evidence for establishing method to determine SEA in real samples.


Assuntos
Técnicas de Química Analítica/métodos , Enterotoxinas/análise , Enterotoxinas/biossíntese , Staphylococcus aureus/química , Água/química , Cromatografia de Afinidade , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Enterotoxinas/isolamento & purificação , Engenharia Genética , Espectrometria de Massas , Proteínas Recombinantes/análise , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Staphylococcus aureus/genética
13.
J Sep Sci ; 40(13): 2827-2837, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28556539

RESUMO

Isoflavones are natural substances that exhibit hormone-like pharmacological activities. The separation of isoflavones remains an analytical challenge because of their similar structures. We show that ultra-high performance supercritical fluid chromatography can be an appropriate tool to achieve the fast separation of 12 common dietary isoflavones. Among the five tested columns the Torus DEA column was found to be the most effective column for the separation of these isoflavones. The impact of individual parameters on the retention time and separation factor was evaluated. These parameters were optimized to develop a simple, rapid, and green method for the separation of the 12 target analytes. It only took 12.91 min using gradient elution with methanol as an organic modifier and formic acid as an additive. These isoflavones were determined with limit of quantitation ranging from 0.10 to 0.50 µg/mL, which was sufficient for reliable determination of various matrixes.


Assuntos
Cromatografia com Fluido Supercrítico , Isoflavonas/isolamento & purificação , Metanol
14.
Molecules ; 21(11)2016 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-27834935

RESUMO

In this paper an analytical method based on high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) for the determination of coumarin and its derivatives in tobacco products was developed. The MS/MS fragmentation pathways of the eight coumarins were elucidated. The new analytical method was defined based on two main axes, an extraction procedure with acetonitrile and analyte detection performed by HPLC-MS/MS in electron impact mode. The excellent selectivity and sensitivity achieved in multiple reaction monitoring (MRM) mode allowed satisfactory confirmation and quantitation for the coumarin flavor additives. Under the optimized gradient elution conditions, it took only 4.5 min to separate all eight coumarins. Good linearity for all the analytes were confirmed by the correlation coefficient r², ranging from 0.9987 to 0.9996. The limits of detection (LODs) and limits of quantitation (LOQs) of these compounds were in the range of 0.5-1.7 µg/kg and 1.7-5.2 µg/kg, respectively. The average recoveries at three spiked levels (LOQ, 1.5LOQ, 2LOQ) were all in the range of 69.6%-95.1% with RSDs (n = 6) lower than 5.3%. The method of HPLC-MS/MS developed in this study was initially applied to the research of coumarin flavor additives in tobacco products collected from the located market in Beijing from China and proved to be accurate, sensitive, convenient and practical.


Assuntos
Cromatografia Líquida , Cumarínicos/química , Nicotiana/química , Espectrometria de Massas em Tandem , Cromatografia Líquida de Alta Pressão , Cumarínicos/isolamento & purificação , Aromatizantes/química , Estrutura Molecular , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Solventes
15.
J Chromatogr A ; 1446: 59-69, 2016 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-27086566

RESUMO

A novel, rapid and simple analytical method was developed for the quantitative determination of crocin, crocetin and geniposide in soft drink, pastry and instant noodles. The solid samples were relatively homogenized into powders and fragments. The gardenia yellow colorants were successively extracted with methanol using ultrasound-assisted extraction. The analytes were quantitatively measured in the extracts by liquid chromatography coupled with electrospray ionization tandem mass spectrometry. High correlation coefficients (r(2)>0.995) of crocin, crocetin and geniposide were obtained within their linear ranges respectively (50-1000ng/mL, 50-1000ng/mL, 15-240ng/mL) by external standard method. The limits of detection (LODs) were 0.02µg/g for crocin, 0.01µg/g for crocetin and 0.002µg/g for geniposide. And the limits of quantitation (LOQs) were in the ranges of 0.05-0.45µg/g for crocin, and in the ranges of 0.042-0.32µg/g for crocetin, and in the ranges of 0.02-0.15µg/g for geniposide in soft drink, pastry and instant noodles samples. The average recoveries of crocin, crocetin and geniposide ranged from 81.3% to 117.6% in soft drink, pastry and instant noodles. The intra- and inter-day precisions were respectively in the range of 1.3-4.8% and 1.7-11.8% in soft drink, pastry and instant noodle. The developed methods were successfully validated and applied to the soft drink, pastry, and instant noodles collected from the located market in Beijing from China. Crocin, crocetin and geniposide were detected in the collected samples. The average concentrations ranged from 0.84 to 4.20mg/g for crocin, and from 0.62 to 3.11mg/g for crocetin, and from 0.18 to 0.79mg/g for gardenia in various food samples. The method can provide evidences for government to determine gardenia yellow pigments and geniposide in food.


Assuntos
Carotenoides/análise , Corantes/análise , Análise de Alimentos , Gardenia/química , Iridoides/análise , Extratos Vegetais/química , Pequim , Bebidas Gaseificadas/análise , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Vitamina A/análogos & derivados
16.
J Chromatogr A ; 1432: 132-9, 2016 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-26780846

RESUMO

An analytical method based on ultra-high performance supercritical fluid chromatography (UHPSFC) with photo-diode array detection (PDA) has been developed to quantify 15 sulfonamides and their N4-acetylation metabolites in serum. Under the optimized gradient elution conditions, it took only 7min to separate all 15 sulfonamides and the critical pairs of each parent drug and metabolite were completely separated. Variables affecting the UHPSFC were optimized to get a better separation. The performance of the developed method was evaluated. The UHPSFC method allowed the baseline separation and determination of 15 sulfonamides and metabolites with limit of detection ranging from 0.15 to 0.35µg/mL. Recoveries between 90.1 and 102.2% were obtained with satisfactory precision since relative standard deviations were always below 3%. The proposed method is simple, accurate, time-saving and green, it is applicable to a variety of sulfonamides detection in serum samples.


Assuntos
Sulfonamidas/sangue , Cromatografia com Fluido Supercrítico/métodos , Humanos , Sulfanilamidas/sangue
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