The preparation and mass spectrometric studies of carboxy-substituted oxazoles derived from (S)-serine

1976 ◽  
Vol 29 (2) ◽  
pp. 375 ◽  
Author(s):  
MJ O'Conner ◽  
JF Smith ◽  
S Teo
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Carboxylic Acid ◽  
Sodium Salt ◽  
Ring System ◽  
Mass Spectrometric ◽  
Ethyl Esters ◽  
Gas Chromatography Mass Spectrometry ◽  
Oxazole Ring ◽  
Alkaline Conditions

The copper(11) complex formed by the reaction of bis((S)-serinato)copper(11) and formaldehyde under alkaline conditions was treated with sodium borohydride to give the sodium salt of dihydro-1 H,3H,5H- oxazolo[3,4-c]oxazole-7a-carboxylic acid. This reaction does not cause appreciable cleavage of the oxazole ring system. The methyl and ethyl esters of the acid were prepared and characterized by gas chromatography/mass spectrometry (g.c.-ms.). Breakdown patterns involving loss of formaldehyde are described.

scholarly journals IDENTIFICATION OF BIOACTIVE COMPOUNDS BY GAS CHROMATOGRAPHY-MASS SPECTROMETRY ANALYSIS OF SYZYGIUM JAMBOS (L.) COLLECTED FROM WESTERN GHATS REGION COIMBATORE, TAMIL NADU

2016 ◽  
Vol 10 (1) ◽  
pp. 364 ◽  
Author(s):  
Devakumar Devakumar Joseph ◽  
Keerthana Veerasamy ◽  
Sudha Siva Singaram
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Carboxylic Acid ◽  
Bioactive Compounds ◽  
Leaf Extract ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Spectrometry Analysis ◽  
Syzygium Jambos ◽  
Chromatography Mass Spectrometry

ABSTRACTObjective: The aim of this study was to investigate the presence of bioactive compounds in the methanolic leaf extract of Syzygium jambos.Methods: Collected leaves were shade dried and made into fine powder, extracted with methanol, and the methanolic extract was prepared andanalyzed for the presence of bioactive compounds by gas chromatography-mass spectrometry (GC-MS). The mass spectrum of the chromatographywas matched with NIST and WILEY Libraries.Results: The GC-MS analysis revealed the presence of 45 active compounds in the extract. From the GC-MS investigation, 1-Deoxy-d-mannitol3-methyl-2-methylsulfanyl-5-nitro-6-pyridin-4-ylpyrimidin-4-one, 3-Pentadecylphenol, 2-biphenylene carboxylic acid, Quinoline-3-carboxylic acid,and Stigmast-5-en-3-ol are important phytoconstituents which have antipyretic and antiparasitic activities.Conclusion: The present investigation revealed preliminary information on phytocompounds presented in S. jambos leaf extract which is very usefulfor the human community.Keywords: Syzygium jambos, Gas chromatography-mass spectrometry analysis, 1-Deoxy-d-mannitol, Phytoconstituents, Methanolic leaf extract.

scholarly journals Development, Optimization and Validation of a Sustainable and Quantifiable Methodology for the Determination of 2,4,6-Trichloroanisole, 2,3,4,6-Tetrachloroanisole, 2,4,6-Tribromoanisole, Pentachloroanisole, 2-Methylisoborneole and Geosmin in Air

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1571
Author(s):  
Patricia Jové ◽  
Marina Vives-Mestres ◽  
Raquel De Nadal ◽  
Maria Verdum
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
High Temperature ◽  
Thermal Desorption ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Air Analysis ◽  
Good Linearity ◽  
Repeatability And Reproducibility

Compounds 2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloroanisole (PCA), 2-methylisoborneol (2MIB) and geosmin (GSM) have been reported as being responsible for cork and wine taint. A sustainable method based on thermal desorption-gas chromatography–mass spectrometry (TD-GC/MS) has been developed and optimized, taking into account desorption parameters and chromatographic and mass spectrometric conditions. The combination of parameters that jointly maximized the compound detection was as follows: desorption temperature at 300 °C, desorption time at 30 min, cryo-temperature at 20 °C and trap high temperature at 305 °C. The proposed methodology showed a good linearity (R ≤ 0.994) within the tested range (from 0.1 to 2 ng) for all target compounds. The precision expressed as repeatability and reproducibility was RSD < 10% in both. The limits of quantification ranged from 0.05 to 0.1 ng. The developed methodology and the sampling rates (R-values) of all targeted compounds (from 0.013 to 0.071 m3 h−1) were applied to the air analysis of two wineries. The results showed that the developed methodology is a sustainable and useful tool for the determination of these compounds in air.

scholarly journals COMPARATIVE STUDY OF ALCOHOL EXTRACTS OF PARTICLES OF CALENDULA OFFICINALIS L. DECORA-TIVE NEON MARK BY GAS CHROMATOGRAPHY/MASS-SPECTROMETRY

2020 ◽  
pp. 207-213
Author(s):  
Marina Gennad'yevna Pervova ◽  
Artem Andreyevich Burgart ◽  
Mariya Andreyevna Samorukova ◽  
Tat'yana Viktorovna Shatunova ◽  
Marina Vadimovna Semenovykh ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Component Composition ◽  
Ethyl Esters ◽  
Biologically Active ◽  
Gas Chromatography Mass Spectrometry ◽  
Mass Yield ◽  
Calendula Officinalis ◽  
Chromatography Mass Spectrometry ◽  
Calendula Officinalis L

The paper presents the results of a comparative analysis of the component composition of alcoholic extracts of particles of Calendula officinalis L. decorative Neon mark: stalks, roots, leaves, flowers, etc., by gas chromatography/mass spectrometry. As a result of the study, more than 30 biologically active compounds (BAС) were identified that belong to different classes of organic compounds (including sesquiterpens, hydrocarbons, fatty acids and their ethyl esters, phytosterols). Their relative quantitative assessment was calculated by the method of internal normalization. It was found that the mass yield of extractable substances depends on the part of the plant used: the maximum (about 10%) from the petals and flowers, the minimum (less than 1%) from the roots. It has been established that the detected BAC is contained in all parts of the plant, but their content varies greatly: the most enriched are petals and flowers, the least - the stems, leaves, roots. Vitamin E is found only in flowers, flower petals and calyxes. The presence of a large number of phytosteros in Calendula officinalis L. is of interest for further pharmacognostic studies of this plant.

Gas Chromatographic-Mass Spectrometric Detection and Quantitation of Lincomycin in Animal Feedingstuffs

1984 ◽  
Vol 67 (3) ◽  
pp. 582-588
Author(s):  
Cecil H McMurray ◽  
W John Blanchflower ◽  
Desmond A Rice
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Retention Time ◽  
Coefficient Of Variation ◽  
Chemical Ionization ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Ionization Mode ◽  
Main Fragment ◽  
Chromatographic Mass

Abstract A substantially Improved assay was developed for lincomycin A in animal feedingstuffs. The assay allows unambiguous quantitation of at least 0.1 ppm in feed. Lincomycin B did not interfere because of differences in both retention time and mass of the main fragment ion in electron impact (EI) spectra. The assay using single ion monitoring with EI detection would not discriminate between lincomycin A and clindamycin. The presence of the latter was easily confirmed by using gas chromatography-mass spectrometry in the chemical ionization mode. The assay for lincomycin A was linear in the range 0–40 ng applied to the gas chromatographic column. The recovery was 93.4 ± 4.2% at 1 and 5 ppm and 86.2 ± 5.5% at 0.1 ppm in feed. The coefficient of variation of the assay was 4.8% at both 1 and 5 ppm, and was 6.43% at 0.1 ppm.

Capillary Column Gas Chromatographic Determination of Ethyl Carbamate in Alcoholic Beverages with Confirmation by Gas Chromatography/Mass Spectrometry

1987 ◽  
Vol 70 (4) ◽  
pp. 749-751 ◽  
Author(s):  
Henry B S Conacher ◽  
Denis B Page ◽  
Benjamin P Y Lau ◽  
James F Lawrence ◽  
Ruth Bailey ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Capillary Column ◽  
Methylene Chloride ◽  
Ethyl Carbamate ◽  
Mass Spectrometric ◽  
Mass Spectrometric Detection ◽  
Alcoholic Beverages ◽  
Gas Chromatography Mass Spectrometry ◽  
Acetate Solution

Abstract A method is described for determining ethyl carbamate at low \i%l kg levels in several types of alcoholic beverages by capillary column gas chromatography with Hall electrolytic conductivity detection and confirmation by mass spectrometry. Samples are diluted to obtain a uniform concentration of ethanol (ca 10%) then saturated with NaCl and extracted with methylene chloride. Extracts are evaporated to a small volume and injected in ethyl acetate solution for chromatographic analysis. The method was evaluated by 5 laboratories, 4 employing the Hall detector and one using mass spectrometric detection. Overall between-laboratory mean percent recoveries were: wine, 85.3 ± 21.0% coefficient of variation (CV) (spiking level 20- 45 μg/kg); sherry, 83.8 ± 16.1% CV (spiking level, 81-142 μg/kg);whiskey, 79.5 ± 13.9% CV (spiking level 127-190 Mg/kg); and brandy, 85.0 ± 12.5% CV (spiking level 297-446 μg/kg). Mass spectrometric results agreed well with the Hall results for all commodities. Detection limits were about 5 μg/kg for the Hall detector and about 0.5 μg/kg for mass spectrometric detection.

Gas chromatographic-mass spectrometric assay for 6-hydroxymelatonin sulfate and 6-hydroxymelatonin glucuronide in urine.

1987 ◽  
Vol 33 (4) ◽  
pp. 453-457 ◽  
Author(s):  
P L Francis ◽  
A M Leone ◽  
I M Young ◽  
P Stovell ◽  
R E Silman
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Original Sample ◽  
Chromatography Mass Spectrometry ◽  
Chromatographic Mass

Abstract Circulating melatonin is hydroxylated to 6-hydroxymelatonin and excreted in urine as the sulfate and glucuronide conjugates. We extracted these two compounds from urine by using octadecylsilane-bonded silica cartridges to eliminate most of the urea and electrolytes, and silica cartridges to separate the sulfate and glucuronide conjugates. After hydrolyzing the separated conjugates enzymically, we determined the free hydroxymelatonin by gas chromatography-mass spectrometry. Though recoveries were low and variable, we were able to quantify the analyte in the original sample by adding deuterated sulfate and glucuronide conjugates to the urines before extraction.

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