USE OF ETHYL ESTERS OF TRYPTOPHAN TO BYPASS THE ABSORPTION DEFECT IN HARTNUP DISEASE

2009 ◽  
Vol 48 (1) ◽  
pp. 22-24
2018 ◽  
Vol 18 (2) ◽  
pp. 115-131
Author(s):  
Liang Heng-Yu ◽  
Su Ning ◽  
Guo Kun ◽  
Wang Yuan ◽  
Yang De-Yu

Five Saccharomyces cerevisiae strains (Chinese indigenous yeasts SC5, WC5, SC8, CC17 and commercial starter F15) were inoculated into Cabernet sauvignon grape must and fermented at pilot scale. For the first time, combination of 1H NMR, HS-SPME/GC-MS and HPLC-DAD-ESI-MS/MS metabonomic profiling techniques was performed to analyze the global chemical fingerprints of sampled wines at the end of alcoholic and malolactic fermentation respectively, then 13 non-volatile flavor compounds, 52 volatile organic aromas and 43 polyphenolic molecules were identified and determined correspondently. All principal component analysis (PCA) of two fermentation stages based on the analytical results of 1H NMR, HS-SPME/GC-MS and HPLC-DAD-ESI-MS/MS divided these strains into three clusters: (1) SC5 and SC8, (2) WC5 and F15 and (3) CC17. The wine fermented by indigenous yeast, CC17, showed a very unique chemical profile, such as low pH and high color intensity, reduced amino acids (including proline) and the lowest total higher alcohols levels, most of the fixed acids, glycerol, ethyl esters and anthocyanins concentrations. The statistical results indicate that CC17 strain possesses very special anabolism and catabolism abilities on such substances in grape juice and has potentiality to produce characteristic wines with high qualities.


2019 ◽  
Vol 26 (1) ◽  
pp. 177-196 ◽  
Author(s):  
Mateusz Kacper Woźniak ◽  
Marek Wiergowski ◽  
Jacek Namieśnik ◽  
Marek Biziuk

Background:Ethyl alcohol is the most popular legal drug, but its excessive consumption causes social problems. Despite many public campaigns against alcohol use, car accidents, instances of aggressive behaviour, sexual assaults and deterioration in labor productivity caused by inebriated people is still commonplace. Fast and easy diagnosis of alcohol consumption is required in order to introduce proper and effective therapy, and is crucial in forensic toxicology analysis. The easiest method to prove alcohol intake is determination of ethanol in body fluids or in breath. However, since ethanol is rapidly metabolized in the human organism, only recent consumption can be detected using this method. Because of that, the determination of alcohol biomarkers was introduced for monitoring alcohol consumption over a wider range of time.Objective:The objective of this study was to review published studies focusing on the sample preparation methods and chromatographic or biochemical techniques for the determination of alcohol biomarkers in whole blood, plasma, serum and urine.Methods:An electronic literature search was performed to discuss possibilities and limitations of application of alcohol biomarkers in toxicological analysis.Results:Authors described the markers of alcohol consumption such as: ethanol, its nonoxidative metabolites (ethyl glucuronide, ethyl sulfate, phosphatidylethanol, ethyl phosphate, fatty acid ethyl esters) and oxidative metabolites (acetaldehyde and acetaldehyde adducts). We also discussed issues concerning the detection window of these biomarkers, and possibilities and limitations of their use in routine analytical toxicology for monitoring alcohol consumption or sobriety during alcohol therapy.


1981 ◽  
Vol 46 (9) ◽  
pp. 2116-2122 ◽  
Author(s):  
Jiří Křepelka ◽  
Jiří Roubík ◽  
Jiří Holubek

Alkylation of 7-ethyl-4-(4-ethylphenyl)-2,3-dibromo-1-naphthol (I) with ethyl esters of ω-bromoalkanoic acids XX-XXIII in a non-aqueous medium gave the 1-substitution derivatives II, IV, VI and VIII which were hydrolyzed to the acids III, V, VII and IX. The acid III was used for syntheses of the esters X-XIII and amides XIV-XVIII. Compounds II-XVIII exhibited moderate antineoplastic effects in animals with transplanted tumours; best results were observed with the compound II.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3193
Author(s):  
Bagda Sagynaikyzy Zhumakanova ◽  
Izabela Korona-Głowniak ◽  
Krystyna Skalicka-Woźniak ◽  
Agnieszka Ludwiczuk ◽  
Tomasz Baj ◽  
...  

The chemical composition of the hydroethanolic extracts (60% v/v) from the aerial parts of Thymus marschallianus Willd (TM) and Thymus seravschanicus Klokov (TS) from Southern Kazakhstan flora was analyzed together with their hexane fractions. Determination of antibacterial, antifungal and antioxidant activities of both extracts was also performed. RP-HPLC/PDA and HPLC/ESI-QTOF-MS showed that there were some differences between the composition of both extracts. The most characteristic components of TM were rosmarinic acid, protocatechuic acid, luteolin 7-O-glucoside, and apigenin 7-O-glucuronide, while protocatechuic acid, luteolin 7-O-glucoside, luteolin 7-O-glucuronide, and eriodictyol predominated in TS. The content of polyplenols was higher in TS than in TM. The GC-MS analysis of the volatile fraction of both examined extracts revealed the presence of thymol and carvacrol. Additionally, sesquiterpenoids, fatty acids, and their ethyl esters were found in TM, and fatty acid methyl esters in TS. The antioxidant activity of both extracts was similar. The antibacterial activity of TS extract was somewhat higher than TM, while antifungal activity was the same. TS extract was the most active against Helicobacter pylori ATCC 43504 with MIC (minimal inhibitory concentration) = 0.625 mg/mL, exerting a bactericidal effect. The obtained data provide novel information about the phytochemistry of both thyme species and suggest new potential application of TS as a source of bioactive compounds, especially with anti-H. pylori activity.


2020 ◽  
Vol 5 (11) ◽  
Author(s):  
Lindsey A Welch

AbstractGreen chemistry and sustainability are important concepts to incorporate into the undergraduate chemistry curriculum. Through the development of innovative undergraduate chemistry research projects in these areas, retention of students in the physical sciences can be improved. This paper describes two projects in undergraduate catalysis research: hydrogenation of furfural and the esterification of biooil from pyrolyzed wood. Catalytic transfer hydrogenation (CTH) of furfural with Pd/C led to the production of furfuryl alcohol, furfuryl isopropyl ether, 2-methylfuran, and tetrahydrofurfuryl alcohol. The metal chloride additives improved selectivity for furfuryl alcohol and furfuryl isopropyl ether. Catalytic conversion of pyrolyzed wood biooil in ethanol with a solid acid catalyst yielded ethyl esters, including ethyl acetate and ethyl propionate, as characterized by GC/MS These projects are described in the context of engaging undergraduate students in hands-on research for the purpose of improving retention and persistence, as well as preparing young scientists to enter graduate programs and the STEM workforce.


Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 69
Author(s):  
Alberto Martínez ◽  
Rocío Velázquez ◽  
Emiliano Zamora ◽  
María L. Franco ◽  
Camille Garzo ◽  
...  

The killer strains of Torulaspora delbrueckii can be used to improve the dominance of this yeast during must fermentation. The present work analyzes its usefulness for traditional sparkling wine making. T. delbrueckii killer strain dominated base wine fermentation better than non-killer strains and produced dried wines. The foam ability of T. delbrueckii base wines was very low compared to that of Saccharomyces cerevisiae. Significant positive correlations of foam parameters were found with some amounts of C4–C16 ethyl esters and proteins, and negative correlations with some antifoam alcohols. The organoleptic quality of T. delbrueckii base wines was considered unusual for cava making. While S. cerevisiae (single or mixed with T. delbrueckii) completed the second fermentation to produce dry sparkling wines with high CO2 pressure, single T. delbrueckii did not complete this fermentation, leaving sweet wines with low CO2 pressure. Death due to CO2 pressure was much higher in T. delbrueckii than in S. cerevisiae, making any killer effect of S. cerevisiae on T. delbrueckii irrelevant. However, the organoleptic quality of cava inoculated with mixtures of the two yeast species was better than that of wine inoculated exclusively with S. cerevisiae, and no deterioration in the quality of the foam was observed.


2021 ◽  
Vol 83 ◽  
pp. 106946
Author(s):  
Meeyoung O. Min ◽  
Sonia Minnes ◽  
Hasina Momotaz ◽  
Lynn T. Singer ◽  
Anna Wasden ◽  
...  

2021 ◽  
Vol 413 (11) ◽  
pp. 3093-3105
Author(s):  
Mateusz Kacper Woźniak ◽  
Laura Banaszkiewicz ◽  
Justyna Aszyk ◽  
Marek Wiergowski ◽  
Iwona Jańczewska ◽  
...  

AbstractAlcohol consumption during pregnancy constitutes one of the leading preventable causes of birth defects and neurodevelopmental disorders in the exposed children. Fatty acid ethyl esters (FAEEs), ethyl glucuronide (EtG) and ethyl sulfate (EtS) have been studied as potential biomarkers of alcohol consumption. However, most analytical approaches proposed for their analysis in meconium samples consist of separated extraction procedures requiring the use of two meconium aliquots, which is costly in terms of both time and materials. Therefore, the aim of this study was to develop and validate a method for the simultaneous extraction of 9 FAEEs, EtG and EtS from one meconium aliquot. The sample was homogenized using methanol, and then FAEEs were extracted with hexane while EtG and EtS were isolated using acetonitrile. Then, extracts were applied to solid-phase extraction columns and analysed by gas chromatography mass spectrometry (FAEEs) and liquid chromatography tandem mass spectrometry (EtG and EtS). Calibration curves were linear with r values greater than 0.99. The LODs ranged from 0.8 to 7.5 ng/g for FAEEs and were 0.2 ng/g and 0.8 ng/g for EtS and EtG, respectively. LOQs ranged from 5 to 25 ng/g for FAEEs and were 1 ng/g and 2.5 ng/g for EtS and EtG, respectively. Accuracies and precisions were between 93.8 and 107% and between 3.5 and 9.7%, respectively. The recovery values ranged from 89.1 to 109%. The method proved to be sensitive, specific, simple and fast and allowed for the reduction of the amount of organic solvent used for extraction compared to other published data while higher recoveries were obtained. The method was used for analysis of meconium samples in two cases of mothers who were consuming alcohol during pregnancy.


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