Comparison of Experimental Methods Used for Finding of Temperature Rise in Electrotechnics

Má bakalářská práce je zaměřená na různé metody měření oteplení na elektrických strojích a přístrojích. Toto oteplení vzniká vlivem působení ztrát. Tyto ztráty jsou v první kapitole teoreticky rozebrány. Ve druhé kapitole jsou vysvětlené různé metody bezkontaktního a kontaktního měření teploty a uvedené výhody a nevýhody těchto metod. V praktické části je provedeno měření teploty na jističi nízkého napětí pomoci termokamery a termočlánku. Dosažené výsledky jsou zpracovány do grafů a následně graficky porovnány. V závěru mé bakalářské práce jsou tyto výsledky rozebrány a uvedeny výhody a nevýhody těchto metod měření teploty.My bachelor thesis is focused on different kinds of methods how to measure a heating of electrical machines and devices. The heating is created by an influence of losses. The losses are theoretically described in the first chapter. Description of different kinds of methods of contact and contactless thermal measuring is located in the second chapter, where are also mentioned advantages and disadvantages of these methods. The practical part consists of the measuring of a temperature on a circuit breaker by thermocamera and thermocouple. These measured values are shown in graphs and are graphically compared. The results, the advantages and the disadvantages of these kinds of methods are discussed in the conclusion of the bachelor thesis.410 - Katedra elektroenergetikyvýborn

Evolution of Biocatalysis at Novartis over the last 40 Years

The fortieth anniversary of biocatalysis started at Ciba-Geigy and later at Novartis is a great time to pause and reflect on development of science and technology in this field. Enzyme-based synthesis became a highly valued enabling tool for pharmaceutical research and development over the last decades. In this perspective we aim to discuss how the scientific approaches and trends evolved over the time and present future challenges and opportunities

Human FMO2-based microbial whole-cell catalysts for drug metabolite synthesis

Background: Getting access to authentic human drug metabolites is an important issue during the drug discovery and development process. Employing recombinant microorganisms as whole-cell biocatalysts constitutes an elegant alternative to organic synthesis to produce these compounds. The present work aimed for the generation of an efficient whole-cell catalyst based on the flavin monooxygenase isoform 2 (FMO2), which is part of the human phase I metabolism. Results: We show for the first time the functional expression of human FMO2 in E. coli. Truncations of the C-terminal membrane anchor region did not result in soluble FMO2 protein, but had a significant effect on levels of recombinant protein. The FMO2 biocatalysts were employed for substrate screening purposes, revealing trifluoperazine and propranolol as FMO2 substrates. Biomass cultivation on the 100 L scale afforded active catalyst for biotransformations on preparative scale. The whole-cell conversion of trifluoperazine resulted in perfectly selective oxidation to 48 mg (46% yield) of the corresponding N1-oxide with a purity >98%. Conclusions: The generated FMO2 whole-cell catalysts are not only useful as screening tool for human metabolites of drug molecules but more importantly also for their chemo- and regioselective preparation on the multi-milligram scale

BM CDT Research Proposals 2018/19 from GDC BIR. Title: Stereoselective, scalable route towards phosphorothioate analogues of ATP

Enantioselective synthesis of phosphorothioate analogues of adenosine 5'-triphosphate is difficult to achieve in highly atom and cost-efficient way.1 Novel ideas to address this challenge are sought after, which could lead to a scalable and sustainable route towards analogues of (Sp)-ATP-αS

Human xanthine oxidase recombinant in E. coli: a whole cell catalyst for preparative drug metabolites synthesis

Human xanthine oxidoreductase (XOR), which is responsible for the final steps of the purine metabolism pathway and involved in oxidative drug metabolism, was successfully expressed in Escherichia coli BL21(DE3) Gold. Recombinant human (rh) XOR yielded higher productivity with the gene sequence optimized for expression in E.coli than with the native gene sequence. Induction of XOR expression with lactose or IPTG resulted in complete loss of activity whereas shake flasks cultures using media rather poor in nutrients resulted in functional XOR expression in the stationary phase. LB medium was used for a 25 L fermentation in fed-batch mode, which led to a 5 fold increase of the enzyme yield when compared to production in shake flasks. Quinazoline was used as a substrate on the semi-preparative scale using an optimized whole cell biotransformation protocol, yielding 73 mg of the isolated product, 4-quinazolinone, from 100 mg of starting material

Production of recombinant human aldehyde oxidase in E. coli and optimization of its application for preparative synthesis of oxidized drug metabolites

Recombinant human aldehyde oxidase (AO) was expressed in Escherichia coli. Different cell disruption methods and conditions of cell culture in shake flasks and bioreactors and of biotransformation on an analytical scale were tested in order to optimize the synthesis of oxidized AO drug metabolites. The enzyme yield was increased 24-fold by optimizing the cell culture conditions. The highest yield was achieved in a 25 l stirred tank bioreactor under non-oxygen-limited conditions and high lactose feed rate. Suspensions of highly concentrated and well aerated whole cells at neutral pH and relatively low temperatures led to the best conversion. The solvent for the substrate and the buffering agent for the biotransformation had an important influence. In a biotransformation with AO, 210 mg of famciclovir were converted to diacetylpenciclovir with a yield of 82%. The optimized protocol represents a viable method for the preparative synthesis of oxidized AO metabolites of drugs

Absorption, distribution, metabolism and excretion of the oral prostaglandin D2 receptor 2 (DP2) antagonist fevipiprant (QAW039) in healthy volunteers and in vitro

Fevipiprant is a novel oral prostaglandin D2 receptor 2 (DP2; also known as CRTh2) antagonist, which is currently in development for the treatment of severe asthma and atopic dermatitis. We investigated the absorption, distribution, metabolism, and excretion properties of fevipiprant in healthy subjects after a single 200 mg dose of [14C]-radiolabeled fevipiprant. Fevipiprant and metabolites were analyzed by liquid chromatography coupled to tandem mass spectrometry and radioactivity measurements, and mechanistic in vitro studies were performed to investigate clearance pathways and covalent plasma protein binding. Biotransformation of fevipiprant involved predominantly an inactive acyl glucuronide (AG) metabolite, which was detected in plasma and excreta, representing 28% of excreted drug-related material. The AG metabolite was found to covalently bind to human plasma proteins, likely albumin. Excretion was predominantly as unchanged fevipiprant in urine and feces, indicating clearance by renal and possibly biliary excretion. Fevipiprant was found to be a substrate of transporters organic anion transporter 3 (OAT3; renal uptake), multi-drug resistance gene 1 (MDR1; possible biliary excretion), and organic anion-transporting polypeptide 1B3 (OATP1B3; hepatic uptake). Elimination of fevipiprant occurs via glucuronidation by several uridine 5'-diphospho glucuronosyltransferase (UGT) enzymes, as well as direct excretion. These parallel elimination pathways result in a low risk of major drug-drug interactions or pharmacogenetic/ethnic variability for this compound

Additional file 1: of Human FMO2-based microbial whole-cell catalysts for drug metabolite synthesis

Figure S1. 1H NMR of trifluoperazine metabolite; Figure S2. 2D HSQC NMR of trifluoperazine metabolite; Figure S3. 2D HMBC NMR of trifluoperazine metabolite; Figure S4. 1H NMR of benzydamine metabolite and benzydamine; Figure S5. Comparison of DEPT NMR of benzydamine metabolite with 13C NMR of parent benzydamine

Identification of three novel ring expansion metabolites of KAE609 in rat, dog, and human, a new spiroindolone agent for the treatment of malaria

KAE609 is a potent, fast-acting, schizonticidal agent being developed for the treatment of malaria. Following oral dosing of KAE609 to rats and dogs, the major radioactive component in plasma was KAE609. An oxidative metabolite, M18, was the prominent metabolite in rat and dog plasma. KAE609 was well absorbed and extensively metabolized such that low levels of parent compound (≤ 11% of the dose) were detected in feces. The elimination of KAE609 and metabolites was primarily mediated via biliary pathways (≥ 93% of the dose) in the feces of rats and dogs. M37 and M23 were the major metabolites in rat and dog feces, respectively. Amongst the prominent metabolites of KAE609, the isobaric chemical species, M37, was observed, suggesting the involvement of an isomerization or rearrangement during biotransformation. Subsequent structural elucidation of M37 revealed that KAE609, a spiroindolone, undergoes an unusual C-C bond cleavage, followed by a 1, 2-acyl shift to form a ring expansion metabolite M37. The in vitro metabolism of KAE609 in hepatocytes was investigated to understand this novel biotransformation. The metabolism of KAE609 was qualitatively similar across the species studied, thus further investigation was conducted using human recombinant CYP enzymes. The ring expansion reaction was found to be primarily catalyzed by CYP3A4 yielding M37. M37 was then subsequently oxidized to M18 by CYP3A4, and hydroxylated to M23 primarily by CYP1A2. Interestingly, M37 was colorless while M18 and M23 showed orange yellow color. The source of the color of M18 and M23 was attributed to their extended conjugated system of double bonds in the structures