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ObjectiveTo investigate the mechanism of Atractylodis Macrocephalae Rhizoma（AMR） in the treatment of slow-transmission constipation（STC） by observing the effects of AMR on short-chain fatty acids and intestinal barries in STC mice. MethodForty-eight male KM mice were randomly divided into blank group， model group， AMR low-， medium-， high-dose groups（2.5， 5， 10 g·kg-1） and mosapride group（2.5 mg·kg-1）. Except for the blank group， all groups were gavaged with loperamide suspension（5 mg·kg-1） twice daily for 14 d to construct the STC mouse model. At the same time， each drug administration group was given the corresponding drug by gavage for consecutive 14 d， the blank and model groups were gavaged with equal volume of distilled water. The effects of the treatment of AMR on body mass， defecation frequency， fecal water content and intestinal propulsion rate of mice were observed， the pathological changes of mouse colon were observed by hematoxylin-eosin（HE） staining and periodic acid-Schiff（PAS） staining， the levels of gastrin（GAS） and motilin（MTL） in serum were detected by enzyme-linked immunosorbent assay（ELISA）， gas chromatography-mass spectrometry（GC-MS） was used to detect the contents of short-chain fatty acids（SCFAs） in mouse feces， real-time fluorescence quantitative polymerase chain reaction（Real-time PCR） and Western blot were used to determine the mRNA and protein expression levels of zonula occludens-1（ZO-1）， Occludin， and Claudin-1 in the colon of mice. ResultCompared with the blank group， the body mass， defecation frequency， fecal water content and intestinal propulsion rate of mice in the model group were significantly decreased（P<0.05， P<0.01）， the arrangement of colonic tissues was disordered， and the number of goblet cells was reduced， the levels of GAS and MTL in serum were significantly decreased（P<0.01）， and the levels of SCFAs in the feces were on a decreasing trend， with the contents of acetic acid， propionic acid， butyric acid， isobutyric acid and valeric acid were significantly decreased（P<0.05， P<0.01）， the mRNA and protein expression levels of ZO-1， Occludin and Claudin-1 in the colonic tissues were significantly decreased（P<0.01）. The above results suggested that STC mouse model was successfully constructed. Compared with the model group， the body mass， defecation frequency， fecal water content and intestinal propulsion rate of mice in AMP administration groups all increased significantly（P<0.05， P<0.01）， the mucosal layer of the colonic tissues was structurally intact without obvious damage， and the number of goblet cells increased， serum levels of GAS and MTL were significantly increased（P<0.01）， the contents of SCFAs in the feces were all on a rising trend， with the contents of acetic， propionic， butyric and isobutyric acids rising significantly（P<0.05， P<0.01）， the mRNA and protein expression levels of ZO-1， Occludin and Claudin-1 in the colonic tissues were significantly increased（P<0.05， P<0.01）. ConclusionAMR is able to improve the constipation symptoms in STC mice， and its mechanism may be related to increasing the contents of SCFAs in the intestine as well as promoting the mRNA and protein expression levels of ZO-1， Occludin and Claudin-1 in the colon.
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Background Volatile organic compounds (VOCs) in exhaled breath are closely associated with respiratory diseases and are linked to various metabolic reactions in the human body. A quantitative analytical method can provide technical support for studying VOCs related to various diseases. Objective To establish a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method for the determination of 27 VOCs in exhaled breath. Methods VOCs in exhaled breath were collected using a Bio-VOC sampler and enriched with Tenax TA thermal desorption tubes before TD-GC-MS analysis. Standards were collected using thermal desorption tubes and optimized for thermal desorption conditions as well as chromatographic and mass spectrometric conditions: The separation of the 27 VOCs was achieved by an optimized temperature program, the improvement of sensitivity by optimizing quantitative ions, and the increase of VOCs desorption efficiency by optimizing thermal desorption time and temperature. Limit of detection, limit of quantification, accuracy, precision, and stability of the proposed method were investigated by spiking with a blank gas bag, and exhaled breath samples from 20 healthy individuals were collected for an application study of the proposed method. Results The thermal desorption temperature was 280 ℃, and desorption time was 6 min. A VF-624ms chromatographic column was selected for the separation of target substances. The initial temperature of heating program was 35 ℃, maintained for 1 min, and then increased to 100 ℃ at a heating rate of 3 ℃·min−1 for 1 min, followed by increasing to 210 ℃ at a heating rate of 28 ℃·min−1 for 5 min. A quantitative analysis was conducted with a single ion monitoring (SIM) mode. Under these conditions, the 27 VOCs showed good linear relationships in their respective concentration ranges and the correlation coefficients were higher than 0.9990. The limits of detection of the method were in the range of 0.01-0.13 nmol·mol−1, the limits of quantification were in the range of 0.02-0.44 nmol·mol−1, and the spiked recoveries were in the range of 80.1%-120.5%, with intra-batch and inter-batch precision ≤ 18.8% and 17.9% respectively. All substances can be stored at room temperature (23-28 °C) for 7 d and at 4 °C for 14 d. The proposed method was applied to exhaled breath samples from 20 subjects with detection rates≥ 80% (except for trans-2-pentene and decane) and a concentration range of 0.00-465.50 nmol·mol−1. Conclusion The established TD-GC-MS method for quantification of VOCs in exhaled breath is characterized by high sensitivity and good accuracy, and is suitable for quantitative determination of VOCs in exhaled breath, which can provide technical support for the study of exhaled breath VOCs.
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ObjectiveTo screen the differential markers by analyzing volatile components in Dalbergia odorifera and its counterfeits， in order to provide reference for authentication of D. odorifera. MethodThe volatile components in D. odorifera and its counterfeits were detected by headspace gas chromatography-mass spectrometry（HS-GC-MS）， and the GC conditions were heated by procedure（the initial temperature of the column was 50 ℃， the retention time was 1 min， and then the temperature was raised to 300 ℃ at 10 ℃ for 10 min）， the carrier gas was helium， and the flow rate was 1.0 mL·min-1， the split ratio was 10∶1， and the injection volume was 1 mL. The MS conditions used electron bombardment ionization（EI） with the scanning range of m/z 35-550. The compound species were identified by database matching， the relative content of each component was calculated by the peak area normalization method， and principal component analysis（PCA）， orthogonal partial least squares-discrimination analysis（OPLS-DA） and cluster analysis were performed on the detection results by SIMCA 14.1 software， and the differential components of D. odorifera and its counterfeits were screened out according to the variable importance in the projection（VIP） value>2 and P<0.05. ResultA total of 26， 17， 8， 22， 24 and 7 volatile components were identified from D. odorifera， D. bariensis， D. latifolia， D. benthamii， D. pinnata and D. cochinchinensis， respectively. Among them， there were 11 unique volatile components of D. odorifera， 6 unique volatile components of D. bariensis， 3 unique volatile components of D. latifolia， 6 unique volatile components of D. benthamii， 8 unique volatile components of D. pinnata， 4 unique volatile components of D. cochinchinensis. The PCA results showed that， except for D. latifolia and D. cochinchinensis， which could not be clearly distinguished， D. odorifera and other counterfeits could be distributed in a certain area， respectively. The OPLS-DA results showed that D. odorifera and its five counterfeits were clustered into one group each， indicating significant differences in volatile components between D. odorifera and its counterfeits. Finally， a total of 31 differential markers of volatile components between D. odoriferae and its counterfeits were screened. ConclusionHS-GC-MS combined with SIMCA 14.1 software can systematically elucidate the volatile differential components between D. odorifera and its counterfeits， which is suitable for rapid identification of them.
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ObjectiveTo discriminate the age of Arisaema Cum Bile， the combination of headspace solid-phase microextraction （HS-SPME） with gas chromatography-mass spectrometry （GC-MS） was applied to explore the differences of volatile components of unfermented， 1-year fermented， 2-year fermented， and 3-year fermented Arisaema Cum Bile. MethodSamples with different fermentation durations were collected and HS-SPME-GC-MS technology was employed to detect the volatile components of each sample. The relative contents of detected volatile components were processed and analyzed by chemometrics methods such as principal component analysis （PCA）， hierarchical cluster analysis （HCA）， and partial least squares discriminant analysis （PLS-DA）. ResultThe results showed that 145 volatile components were identified. Among these volatile components， the relative contents of heterocyclic， alcohols， aldehydes and aromatics were high. PCA， HCA， and PLS-DA can effectively separate Arisaema Cum Bile with four different ages. Based on variable importance in projection （VIP） value > 1， 73 markers of differential volatile components were identified. The content of 2，6，11-trimethyldodecane and m-xylene in unfermented samples was the highest， and the content difference between them and those in fermented samples was significant （P<0.05）. 2，3-butanediol was detected only in 1-year samples， octane was detected only in 2-year samples， and ethyl heptanoate was detected only in 3-year samples. These components can be used as odor markers for Arisaema Cum Bile with different fermentation years. ConclusionThe identification method of volatile components of Arisaema Cum Bile was established by HS-SPME-GC-MS technology， which can realize the rapid identification of unfermented， 1-year fermented， 2-year fermented， and 3-year fermented samples， and provide a scientific basis for the standardization of processing technology and quality standards of Arisaema Cum Bile.
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@#[Objective] To explore the application of Quality by Design (QbD) tools in assessing geographical variations of Phyllanthus emblica (P. emblica) from five distinct Indian states. [Methods] In the current experiment, the Box-Behnken design with a reduced quartic model and 105 runs was employed with the use of the Design Expert software for randomized response surface mapping. Three different extraction methods (Soxhlet, maceration, and sonication) along with three solventst [distilled water, methanol, and water-methanol mixture (50 : 50 v/v)] were considered in the present study. The anti-oxidant activities, total flavonoid content (TFC), and total phenolic content (TPC) in the P. emblica were determined and analysed by gas chromatography-mass spectrometry (GC-MS) to identify the major components. [Results] The QbD overlay plot showed that the extractive value of the P. emblica was no less than 30% w/w, 2,2-diphenyl-1-picrylhydrazyl (DPPH) no less than 60% mcg/mL (micrograms per millilitre), TFC no less than 75 mg QE/g (milligrams of quercetin equivalents per gram), and TPC no less than 80 mg GAE/g (milligrams of gallic acid equivalents per gram). Moreover, the GC-MS data confirmed the presence of variation in the bioactives of P. emblica extracts. [Conclusion] The model was significant in describing the variation in extractive value, DPPH, TFC, and TPC. The QbD approach may tend to prioritize thoroughness in the extraction process, ultimately resulting in improved quality in the extracted products.
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Objective To establish a rapid qualitative analysis method for volatile organic components in chemicals. Methods Headspace gas chromatography-mass spectrometry was used to qualitatively determine 19 volatile organic components, including benzene, 1,2-dichloroethane, and n-hexane, in chemicals. Different sample amounts, heating temperatures, heating times, and sample volumes were analyzed to assess their effects on detection results and optimize sampling conditions. Results Based on the set chromatography, the optimal sampling process of this method was as follows： 5.0 g sample in a 20.0 mL headspace bottle, incubated at 40 ℃ for 30 minutes in a constant-temperature drying incubator, and a 1.00 mL headspace gas injection. The within-run and between-run relative standard deviations of all components ranged from 0.00% to 21.05% and 0.00% to 33.33%, respectively. The samples stored in sealed glass containers were stable at room temperature for at least 60 days. Conclusion This method offers simplicity, good reproducibility, and stability, making it suitable for rapid qualitative analysis of volatile organic components in chemicals.
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ObjectiveTo analyze the fingerprint of six pungent herbs based on the molecular connectivity index（MCI）and the matching frequency total statistical moment method， and to study the division and integration of the "imprinting template" of their volatile components， so as to find the common "imprinting template" characteristics of the pungent herbs. MethodThe volatile components of six pungent herbs were extracted by steam distillation， and their fingerprints were established by gas chromatography-mass spectrometry（GC-MS） with a programmed temperature increase（80 ℃ for 5 min， 5 ℃·min-1 to 200 ℃ for 5 min， 2 ℃·min-1 to 230 ℃ for 10 min）， a splitting ratio of 20∶1， an electron bombardment ion source（EI） and the detection range of m/z 35-650， and the average MCI and total statistical moment parameters of the fingerprints were calculated. Then the matching frequency method was used to classify， integrate and confirm the chromatographic peaks of the fingerprints of six pungent herbs. ResultThe average zero order， first-order and second-order MCI values of the volatile components of Pogostemonis Herba， Artemisiae Argyi Folium， Atractylodis Rhizoma， Asari Radix et Rhizoma， Magnoliae Flos and Schizonepetae Herba were 9.02， 5.28 and 5.05， respectively. The average values of peak number， total zero-order moment， total first-order moment and total second-order moment were 60， 169×107， 22.49 min and 36.82 min2， respectively. The 20 integrated imprinting templates were obtained by the matching frequency method for the six pungent herbs， among which three were common imprinting templates with the retention times of （25.97±0.21），（26.90±0.20），（31.64±1.24） min， respectively， and the representative components were valencene，β-elemene， caryophyllin， etc. ConclusionMCI combined the matching frequency total statistical moment can divide and integrate the characteristics of imprinting templates of six pungent herbs， and find their common chromatographic imprinting characteristics， which can provide a reference for the determination of effective substances of pungent herbs.
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ObjectiveBy comparing the differences in composition and content of volatile components between Atractylodis Macrocephalae Rhizoma（AMR）and bleaching AMR， bran-fried AMR and bran-fried bleaching AMR， the effect of processing with rice-washed water on the volatile components in AMR and bran-fried AMR were investigated. MethodHeadspace gas chromatography-mass spectrometry（HS-GC-MS）was used to determine the volatile components in raw products， bran-fried products and their processed products with rice-washed water. GC conditions were programmed temperature（starting temperature of 50 ℃， rising to 140 ℃ at 10 ℃·min-1， maintained for 5 min， then rising to 210 ℃ at 4 ℃·min-1）， splitting ratio of 10∶1， high purity helium as the carrier gas and a solvent delay time of 3 min. MS conditions were an electron bombardment ion source（EI） with an electron collision energy of 70 eV， ion source temperature of 230 ℃， and the detection range of m/z 20-650. The relative contents of the components were determined by the peak area normalization method， the obtained sample data were subjected to principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） by SIMCA 14.1 software， and the differential components of AMR and bleaching AMR， and bran-fried AMR and bran-fried bleaching AMR were screened according to variable importance in the projection（VIP） value>1 and P<0.05. ResultA total of 71 volatile components were identified， including 53 in AMR， 50 in bleaching AMR， 51 in bran-fried AMR， and 44 in bran-fried bleaching AMR. OPLS-DA results showed that there were significant differences between AMR and bleaching AMR， bran-fried AMR and bran-fried bleaching AMR， but not between AMR samples from different origins. The compound composition of AMR and bleaching AMR， bran-fried AMR and bran-fried bleaching AMR did not change， but the contents of monoterpenes and sesquiterpenes changed significantly. ConclusionSignificant changes in the contents of volatile components were observed in AMR and bleaching AMR， bran-fried AMR and bran-fried bleaching AMR， among them， 1，2-dimethyl-4-methylidenecyclopentene， 9，10-dehydro-isolongifolene， γ-elemene， zingiberene， atractylone， silphinene， modhephene and （1S，4S，4aS）-1-isopropyl-4，7-dimethyl-1，2，3，4，4a，5-hexahydronaphthalene can be used as candidate differential markers of volatile components of AMR before and after processing with rice-washed water.
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ObjectiveBy exploring the volatile components， polysaccharide composition and changes in the contents of five carbohydrate components of Polygonatum cyrtonema rhizoma before and after processing， and then the effect of yellow rice wine on the odour formation of P. cyrtonema rhizoma was investigated. MethodThe volatile components of P. cyrtonema rhizoma before and after processing were detected by headspace gas chromatography-mass spectrometry（HS-GC-MS）， and sample data were subjected to principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） using SIMCA 14.1， then the differences between these components of P. cyrtonema rhizoma before and after processing were screened according to the principle of variable importance in the projection（VIP） value>1. Crude carbohydrate components in raw and wine-processed P. cyrtonema rhizoma were subjected to oxime and silylation， the carbohydrate components were analyzed by gas chromatography-mass spectrometry（GC-MS/MS）， and the relative contents of various components were calculated by peak area normalization， then quantitative analysis of four carbohydrate components was also carried out. ResultA total of 23 volatile components were identified from the raw products and the wine-processed products， including 15 components in raw products and 20 components in wine-processed products. Among them， 2-methylbutyraldehyde and isovaleraldehyde had a sweet odor and their contents increased after processing， but the contents of hexanal and caproic acid decreased， new components such as 2-acetylfuran and 5-methylfuranal were produced after processing. PCA and OPLS-DA results showed that there were significant differences between raw products and the wine-processed products， a total of 13 differential compounds were screened out， of which 7 showed an upward trend in relative content and 6 showed a downward trend. A total of 7 carbohydrate components， including 5 monosaccharides and 2 disaccharides， were identified in raw products and the wine-processed products. The results of determination showed that the contents of fructose， glucose， mannose and sucrose in P. cyrtonema rhizoma increased after wine-processing， and their increases were 4.54， 1.51， 2.93， 3.66 times， respectively. ConclusionAfter processing， the increase of aromatic flavor of P. cyrtonema rhizoma may be related to the increase of the contents of aldehydes such as 2-methylbutyraldehyde and isovaleraldehyde， while the decrease of raw flavor may be related to the decrease of the contents of volatile components such as hexanal and hexanoic acid， the increase of sweet flavor may be related to the increase of the contents of monosaccharides and oligosaccharides such as fructose and sucrose.
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ObjectiveTo investigate the key compounds affecting the irritation and to clarify the effect of heating and the addition of ginger juice as the auxiliary material during the processing on the irritation of Magnoliae Officinalis Cortex（MOC） by comparing the irritation and composition of volatile oil in MOC and its different processed products. MethodVolatile oil in raw products， water-processed products， ginger-dried products， ginger-fried products（the amounts of ginger were 10%， 50%， respectively） of MOC were extracted by steam distillation and subjected to rabbit eye irritation experiment， and the volatile components of each sample were detected by gas chromatography-mass spectrometry（GC-MS）. Principal component analysis（PCA）and orthogonal partial least squares-discriminant analysis（OPLS-DA） were used to analyze the data of each sample by SIMCA 14.1. The relative contents of different processed products were compared two by two with those of and raw products or ginger-fried products， and the markers that might be related to the irritation were sorted out according to the principles of variable importance in the projection（VIP） value >1 and P<0.05， and the factors influencing the differences in irritation were analyzed. ResultCompared with the blank group， the administration groups all had irritation to the eyes of rabbits， and the degree of irritation was in the order of raw products>water-processed products>ginger-dried products>ginger-fried products（10%）>ginger-fried products（50%）. The results of PCA and OPLS-DA showed that there were differences in the volatile oil from raw products and different processed products. According to VIP value>1 and P<0.05， and combined with the results of eye irritation experiment， ten volatile compounds related to irritation changes were screened out. Among them， cis-cinnamaldehyde was only detected in raw products， the relative contents of β-caryophyllene， （+）-delta-cadinene， α-humulene， γ-muurolene， （-）-isoledene and citral all increased to different degrees， the contents of p-cymene， 1（10）-4-cadinadien-15-ol and β-eudesmol all decreased to different degrees. ConclusionThe irritation of MOC is reduced after heating and processing with ginger juice， and the synergistic effect of both is more effective for reducing irritation. Among the differential markers associated with changes in irritation， the increase in the relative content of citral is closely related to the addition of ginger juice， while the decrease in the relative contents of cis-cinnamaldehyde， p-cymene， 1（10）-4-cadinadien-15-ol is related to heating， and the changes of other components may be related to the synergistic effect of heating and ginger juice.
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OBJECTIVES@#To establish the GC-MS qualitative and quantitative analysis methods for the synthetic cannabinoids, its main matrix and additives in suspicious electronic cigarette (e-cigarette) oil samples.@*METHODS@#The e-cigarette oil samples were analyzed by GC-MS after diluted with methanol. Synthetic cannabinoids, its main matrix and additives in e-cigarette oil samples were qualitatively analyzed by the characteristic fragment ions and retention time. The synthetic cannabinoids were quantitatively analyzed by using the selective ion monitoring mode.@*RESULTS@#The linear range of each compound in GC-MS quantitative method was 0.025-1 mg/mL, the matrix recovery rate was 94%-103%, the intra-day precision relative standard deviations (RSD) was less than 2.5%, and inter-day precision RSD was less than 4.0%. Five indoles or indazole amide synthetic cannabinoids were detected in 25 e-cigarette samples. The main matrixes of e-cigarette samples were propylene glycol and glycerol. Additives such as N,2,3-trimethyl-2-isopropyl butanamide (WS-23), glycerol triacetate and nicotine were detected in some samples. The content range of synthetic cannabinoids in 25 e-cigarette samples was 0.05%-2.74%.@*CONCLUSIONS@#The GC-MS method for synthesizing cannabinoid, matrix and additive in e-cigarette oil samples has good selectivity, high resolution, low detection limit, and can be used for simultaneous qualitative and quantitative analysis of multiple components; The explored fragment ion fragmentation mechanism of the electron bombardment ion source of indole or indoxamide compounds helps to identify such substances or other compounds with similar structures in cases.
Subject(s)
Gas Chromatography-Mass Spectrometry/methods , Electronic Nicotine Delivery Systems , Illicit Drugs/analysis , Indazoles/chemistry , Glycerol/analysis , Cannabinoids , Indoles/chemistry , IonsABSTRACT
The menace of drug resistant pathogens is increasing and their level of evading conventional antimicrobials is rising. It is therefore important to discover new antimicrobials to counter the current challenges. Our preliminary investigation identified Bacillus subtilis subsp. subtilis 168 isolated from soil sample sourced from a river bank in Abuja, Nigeria, as the most potent antibiotic-producing bacteria among the other identified producers. The current study screened for the antimicrobial activity of the extract and fractions of the isolate by broth microdilution method. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and the ratio of the MBC/MIC were determined. All the tested pathogens were susceptible to the ethyl-acetate extract (MIC between 28.70 mg/ml and 57.40 mg/ml). The extract displayed bactericidal activity against all tested pathogens (MBC/MIC between 1.00 and 2.00) while Proteus mirabilis was least susceptible. The extract was purified by vacuum liquid chromatography and the fractions challenged with pathogenic strains. The fraction E was the most potent (MIC between 0.09 mg/ml and 0.75 mg/ml) and also bactericidal against all the test microbes (MBC/MIC between 2.00 and 2.11). GC-MS analysis of the purified sub fraction obtained from fraction E identified 13 compounds with different Retention time and peak areas. Among these were three major compounds which include: (i) bis(2-ethylhexyl) phthalate (ii) 1,4-epoxynaphthalene-1(2H)-methanol, 4,5,7-tris(1,1-dimethylethyl)-3,4-dihydro- (iii) D:B-Friedo-B':A'-neogammacer-5-en-3-ol, (3.beta.)-. Our findings suggest that Bacillus subtilis subsp. subtilis 168 isolated locally could serve as a valuable source of lead compounds for pharmaceutical and biotechnological purposes.
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Covalent organic nanospheres(CONs)were explored as a fiber coating for solid-phase microextraction of genotoxic impurities(GTIs)from active ingredients(AIs).CONs were synthesized by an easy solution-phase procedure at 25℃.The obtained nanospheres exhibited a high specific surface area,good ther-mostability,high acid and alkali resistance,and favorable crystallinity and porosity.Two types of GTIs,alkyl halides(1-iodooctane,1-chlorobenzene,1-bromododecane,1,2-dichlorobenzene,1-bromooctane,1-chlorohexane,and 1,8-dibromooctane)and sulfonate esters(methyl p-toluenesulfonate and ethyl p-toluenesulfonate),were chosen as target molecules for assessing the performance of the coating.The prepared coating achieved high enhancement factors(5097-9799)for the selected GTIs.The strong affinity between CONs and GTIs was tentatively attributed to T-T and hydrophobicity interactions,large surface area of the CONs,and size-matching of the materials.Combined with gas chromatography-mass spectrometry(GC-MS),the established analytical method detected the GTIs in capecitabine and imatinib mesylate samples over a wide linear range(0.2-200 ng/g)with a low detection limit(0.04-2.0 ng/g),satisfactory recovery(80.03％-109.5％),and high repeatability(6.20％-14.8％)and reproducibility(6.20％-14.1％).Therefore,the CON-coated fibers are promising alternatives for the sensitive detection of GTIs in AI samples.
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ObjectiveTo study the changes of primary metabolites and phenols in the fruits of Acanthopanax senticosus at different development stages, so as to provide a theoretical basis for the rational utilization of A. senticosus fruit resources. MethodThe primary metabolites and phenols in the fruits at different development stages were determined via gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) and then compared by multivariate statistical analysis. ResultA total of 274 chromatographic peaks were obtained by GC-MS-based non-targeted metabonomics and 24 differential metabolites were screened out by multivariate statistical analysis. The differential metabolites were mainly concentrated in pentose phosphate pathway, galactose metabolism, ascorbic acid and aldose metabolism pathways. After color conversion, the pentose phosphate pathway and galactose metabolism were activated and increasing sugars were accumulated. The ascorbic acid and aldose metabolism pathways were active before color conversion, with high accumulation of the end product ascorbic acid. The ultra-high liquid chromatography-mass spectrometry (UPLC-MS) identified 28 phenols in the fruits at different development stages. Flavonoids were accumulated mainly at the green ripening stage before color conversion, and phenolic acids were accumulated mainly after color conversion. ConclusionThe accumulation of primary metabolites and phenols in A. senticosus fruits varies significantly among different development stages
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ObjectiveTo analyze the quality changes of Platycladi Semen before and after the deterioration of moth-eaten and rancidity during storage. MethodFour types samples of Platycladi Semen， including normal， moth-eaten， oxidative rancidity and hydrolytic rancidity， were determined for volatile components， odor， and taste based on headspace solid phase microextraction/gas chromatography-mass spectrometry （HS-SPME/GC-MS） and electronic sensory techniques such as electronic nose and electronic tongue. Volatile components were identified by searching the database and manual comparison， the odor and taste were determined by the response values of the electronic nose and electronic tongue sensors， and the difference between samples before and after deterioration was studied by multivariate statistical analysis. ResultA total of 85 compounds were identified in Platycladi Semen samples. Compared with the normal samples， the number of volatile compounds in samples after hydrolytic rancidity decreased by 5， the number of volatile compounds in samples after moth-eaten and oxidative rancidity increased by 1 and 21， respectively. Aldehydes and acids accounted for majority of types. Among them， the contents of N-hexanoic acid， hexanal and propionic acid in the samples of oxidative rancidity reached 11.49%， 10.21% and 7.52%， which became the key indicators of rancidity. There was significant variance among the odor components corresponding to W1W， W2W and W1S sensors by electronic nose analysis. It was indicated that the value of sourness in deteriorated samples generally increased by mean of electronic tongue analysis. Compared with normal samples， the moth-eaten samples had changed slightly and rancidity samples had changed significantly especially oxidative rancidity samples of volatile components， odor and taste by multivariate statistical analysis. ConclusionIn terms of Platycladi Semen， the oxidative rancidity caused by nature storage for 12 months has the greatest impact on the quality. Therefore， it should be mainly to prevent oxidative rancidity to ensure the quality of Platycladi Semen.
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Objective: To explore the metabolite profile and metabolic pathways of newly diagnosed multiple myeloma (MM). Methods: Gas chromatography-mass spectrometry (GC-MS) was employed for the high-throughput detection and identification of serum samples from 55 patients with MM and 37 healthy controls matched for age and sex from 2016 to 2017 collected at the First Affiliated Hospital of Soochow University. The relative standard deviation (RSD) of quality control (QC) samples was employed to validate the reproducibility of GC-MS approach. The differential metabolites between patients with MM and healthy controls were detected by partial least squares discrimination analysis (PLS-DA), and t-test with false discovery rate (FDR) correction. Metabolomics pathway analysis (MetPA) was employed to construct metabolic pathways. Results: There were 55 MM patients, including 34 males and 21 females. The median age was 60 years old (42-73 years old). There were 30 cases of IgG type, 9 cases of IgA type, 1 case of IgM type, 2 cases of non-secreted type, 1 case of double clone type and 12 cases of light chain type, including 3 cases of kappa light chain type and 9 cases of lambda light chain type. The result of QC sample test showed that the proportion of compounds with the RSD of the relative content of metabolites < 15% was 70.21% obtained by the reproducibility of GC-MS experimental data, which implied that the experimental data were reliable. A total of 17 metabolites were screened differently with the healthy control group, including myristic acid, hydroxyproline, cysteine, palmitic acid, L-leucine, stearic acid, methionine, phenylalanine, glycerin, serine, isoleucine, tyrosine, valine, citric acid, inositol, threonine, and oxalic acid (VIP>1, P<0.05). Metabolic pathway analysis suggested that metabolic disorders in MM patients comprised mainly phenylalanine metabolism, glyoxylic acid and dicarboxylic acid metabolism, phosphoinositide metabolism, cysteine and methionine metabolism, glycerolipid metabolism, glycine, serine, and threonine metabolism. Conclusion: Compared with normal people, patients with newly diagnosed MM have obvious differences in metabolic profiles and metabolic pathways.
Subject(s)
Male , Female , Humans , Middle Aged , Adult , Aged , Cysteine , Multiple Myeloma/diagnosis , Reproducibility of Results , Metabolome , Metabolomics/methods , Metabolic Networks and Pathways , Methionine , Serine , Phenylalanine , Threonine , BiomarkersABSTRACT
Objective: To establish a method for the determination of methyl isobutyl ketone (MIBK) in urine samples by headspace-gas chromatography-mass spectrometry. Methods: Automatic headspace sampling technique was adopted to optimize the headspace conditions (headspace bottle heating temperature and equilibration time) and gas chromatographic conditions. A total of 5 ml samples were taken and added with 3.0 g ammonium sulfate into a 20 ml headspace bottle. After heated at 60 ℃ for 30 mins, gas from the upper part of headspace bottle was injected into gas chromatography with an injection volume of 100 μl. The target was separated by HP-5MS UI (30 m×0.25 mm×0.25 μm) capillary column and then detected by mass spectrometry detector. The retention time and external standard method were used for qualitative and quantitative analysis of MIBK in samples, respectively. Results: The standard curve of MIBK showed significant linearity between 20.0-1 000.0 μg/L. The standard curve was y=62.9x-652.5, and the correlation coefficient r=0.9998. The detection limit of MIBK was 5.0 μg/L and the quantification limit of MIBK was 16.0 μg/L. The average recovery rate was 95.3%~100.2% at three spiked concentrations of low (50.0 μg/L) , medium (200.0 μg/L) and high (500.0 μg/L) . The intra-day and inter-day precisions were 1.7%~3.8% (n=6) and 1.2%~4.0% (n=6) respectively. This method was stable for the determination of MIBK, and the urine could be kept 14 d at -20 ℃ without significantly loss. Conclusion: This method is proved to be simple, practical and highly sensitive. It can satisfy the request for the determination of urine samples of workers exposed to MIBK.
Subject(s)
Humans , Gas Chromatography-Mass Spectrometry , Methyl n-Butyl KetoneABSTRACT
Objective:To analyze the serum and urinary amino acid (AA) profiles of urolithiasis patients to explore the potential biomarkers for clinical screening and early diagnosis.Methods:Case-control study. Serum and urine samples were collected from 74 urolithiasis patients (aged 20-82 years, 41 men, 33 female) in the department of urology of the First Affiliated Hospital of Fujian Medical University and 35 healthy controls (HC, aged 22-80 years old, 20 men, 15 female) from the health examination center from February 2015 to October 2017. Serum and urinary AA levels of patients and HC were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS) based metabolomic strategy. The multivariate statistical analysis methods of principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS-DA) were employed for modeling. The variable importance projection (VIP) value of OPLS-DA model>1 and P<0.05 of t test were selected to screen the differential amino acid metabolites. The diagnostic capabilities of potential markers were evaluated by receiver operating characteristic (ROC) curve and binary logistic regression analysis. Results:Five AA metabolites including serine, glutamate, aspartic acid, isoleucine and glycine were found, which had statistically significant differences between the patient group and the control group ( P<0.05) and were associated with seven metabolic pathways. Serum serine, glutamate, aspartic acid, isoleucine and urine glycine and aspartic acid were combined into an integrated marker panel whose AUC value was 0.890, the sensitivity was 78.0%, and the specificity was 96.4%. Conclusion:Five amino acids in serum and urine could be used as an integrated biomarker panel for the clinical screening and early diagnosis of urolithiasis, which could provide some experimental basis for molecular urolithiasis research.
ABSTRACT
Docosanol is the only US Food and Drug Administration(FDA)approved over-the-counter topical product for treating recurrent oral-facial herpes simplex labialis.Validated analytical methods for docosanol are required to demonstrate the bioequivalence of docosanol topical products.A gas chromatography/selected ion monitoring mode mass spectrometry(GC/SIM-MS)method was developed and validated for docosanol determination in biological samples.Docosanol and isopropyl palmitate(internal standard)were separated on a high-polarity GC capillary column with(88％cyanopropy)aryl-polysiloxane employed as the stationary phase.The ions of m/z 83 and 256 were selected to monitor docosanol and isopropyl palmitate,respectively;the total run time was 20 min.The GC/SIM-MS method was validated in accordance with US FDA guidelines,and the results met the US FDA acceptance criteria.The docosanol calibration standards were linear in the 100-10000 ng/mL concentration range(R2＞0.994).The recoveries for docosanol from the receptor fluid and skin homogenates were＞93.2％and＞95.8％,respectively.The validated method was successfully applied to analyze ex vivo human cadaver skin permeation samples.On applying Abreva?cream tube and Abreva?cream pump,the amount of doco-sanol that penetrated human cadaver skin at 48 h was 21.5±7.01 and 24.0±6.95 ng/mg,respectively.Accordingly,we concluded that the validated GC/SIM-MS was sensitive,specific,and suitable for quantifying docosanol as a quality control tool.This method can be used for routine analysis as a cost-effective alternative to other techniques.
ABSTRACT
Objective:To analyze the liposoluble components and antioxidant capacity of Caryopteris tangutica. Methods:By using GC-MS, this paper analyzes liposoluble components of different positions of Caryopteris tangutica. By making the removal rate of free radicals with liposoluble components as the index, and making IC 50 as reference indicators to evaluate the antioxidant capacity of lipidsoluble extracts of different parts. Results:There are 31, 40 and 62 compounds identified in the liposoluble components of the stems, leaves and flower, among which unsaturated fatty acids account for the most. The different parts of Caryopteris tangutica all play the role of clearing DPPH and ABTS + free radicals, and the clearing rate of leaves was greater than that of flowers and stems. Conclusion:The unsaturated fatty acids in lipidsoluble components of Caryopteris tangutica are beneficial to the human body, and have antioxidant activity.