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Fosfinoferrocenové konjugáty vybraných aminokyselin / Phosphinoferrocene conjugates of selected amino acidsTauchman, Jiří January 2012 (has links)
A series of chiral phosphinoferrocene amides was prepared by the condensation either of 1'- (diphenylphosphino)ferrocene-1-carboxylic acid (Hdpf) or its planar-chiral 1,2-isomers and amino acid methyl esters in the presence of peptide coupling agents. The resulting phosphinoamides were tested as ligands in Cu-catalyzed asymmetric conjugate additions of diethylzinc to chalcones and in Pd-mediated asymmetric allylic substitution reactions of 1,3- diphenylallyl acetate with the respective nucleophile (alkylation, amination and etherification). The catalytic tests were focused on an optimization of the reaction parameters (solvent, temperature, base, metal/ligand ratio) and on survey of various substrates. Compounds based on Hdpf proved to be better ligands in both catalytic reactions than their planar chiral analogues. In order to rationalize the influence of the ligand structure on the reaction course and also to interpret the catalytic results, several model complexes were prepared and structurally characterized. Other three series of non-chiral complexes were prepared from the corresponding (η6 - arene)ruthenium(II) precursor and Hdpf-glycine conjugates; the neutral complexes of the type [(arene)RuCl2(Hdpf-Gly(R)-κP)] (arene = benzene, p-cymene, hexamethyl-benzene; R = OMe, NH2, OH) as well as two...
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Vliv dusíkaté zátěže mokřadních luk na obsah volných aminokyselin v půdě. / Effect of N eutrofication of wetland soils on organic N content and qualityŠEDA, Martin January 2009 (has links)
This study deals with an effect of fertilization on amount and quality of free amino acids in soil from wet meadows affected by nutrient loading. Free amino acids were analysed in the soil from the field experiment situated at wet meadows, where an increased nutrient input is simulated (fertilizer NPK). The experiment was established on two sites with different types of soil {--} Záblatí with organic soil and Hamr with mineral soil, both areas in the South Bohemia region. The soil was repeatedly sampled for more than two years and year. One part of this study is focused on testing of ninhydrine-method and HPLC-method for measuring free amino acids and efficiency of different extractants.
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Molekulární evoluce meiózy u diploidů a tetraploidů druhu Arabidopsis arenosa / Molecular evolution of meiosis in diploids and tetraploids of Arabidopsis arenosaHolcová, Magdalena January 2017 (has links)
Meiosis is functionally conserved across eukaryotes, thus not expected to vary considerably among different species, and even less so among lineages within a species. However, recent studies showed that this is not necessarily the case in Arabidopsis arenosa. Genome scanning identified an excess differentiation in meiosis genes between A. arenosa diploids and tetraploids, interpreted as meiosis adaptation to the whole genome duplication in tetraploids and differentiation was also found between two diploid lineages. Thus, I present a population-based analysis of positive selection acting on meiosis proteins across multiple lineages of A. arenosa. I showed that meiosis proteins were under positive selection in all diploid lineages, mainly in the Pannonian and South-eastern Carpathian lineage. The evidence for positive selection in diploid lineages suggested differential pathways of meiosis adaptations in the species, probably reflecting the necessity to adapt to local environments, among all to temperature. The highest enrichment of amino acid substitutions (AASs) under positive selection was identified in tetraploids, in consistence with previous genome-scan results. As several interacting meiosis proteins were under positive selection in the same A. arenosa lineage, I hypothesize that the close...
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Izolace čistých aminokyselin z pšeničných otrub / Isolation of pure aminoacids from wheat branSloupová, Klára January 2021 (has links)
Wheat bran is a promising material containing a wide range of useful components, including proteins. In addition, it is produced in significant volumes. Currently, wheat bran is used for the production of energy by combustion and for feed purposes. Gradually, new methods of valorization of this material are being sought. One of the possibilities of using wheat bran is the isolation of proteins, hydrolysis, and separation of selected amino acids. This diploma thesis deals with this issue, it is focused on the recovery of arginine and leucine from a protein isolate. Proteins were extracted from wheat bran by changing the pH. Thanks to the subsequent lyophilization a protein isolate was gained. Prior to hydrolysis of the resulting isolate, a stability test of arginine and leucine amino acid standards was first performed, to which various hydrolysis methods were applied. Acid hydrolysis using a mineralizer, which was applied to the protein isolate, was proved to be the most effective. This was followed by the derivatization of the hydrolysates with OPA and analysis of the resulting hydrolysates by high-performance liquid chromatography with UV-VIS detection. Then, suitable adsorption and desorption conditions were optimized. It was found that the time dependence does not affect the amount of adsorbed material on the sorbent. Therefore, an application time of 15 minutes was chosen. While optimizing the amount of used standard, it was found that the optimal weight was 0.25 g of sorbent. The selected conditions were applied to the protein hydrolyzate. Two fractions were obtained by the separation of selected amino acids due to the change in the pH of the citrate buffer. After the application of this procedure, 0.26 g of arginine and 0.82 g of leucine were obtained from one kilogram after evaporation. From evaporation two, 1.01 g of arginine and 0.25 g of leucine were obtained after evaporation.
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Prediktor vlivu aminokyselinových substitucí na stabilitu proteinů / Predictor of the Effect of Amino Acid Substitutions on Protein StabilityFlax, Michal January 2017 (has links)
This paper deals with prediction of influence of amino acids mutations on protein stability. The prediction is based on different methods of machine learning. Protein mutations are classified as mutations that increase or decrease protein stability. The application also predicts the magnitude of change in Gibbs free energy after the mutation.
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Syntéza a studium nano-strukturovaných perovskitů pro aplikace v organické elektronice / Synthesis and Study of Nano-Structured Perovskites for Applications in Organic ElectronicsJančík Procházková, Anna January 2020 (has links)
Nanočástice perovskitů halogenidů kovů vykazují unikátní vlastnosti, především výjimečně vysoké hodnoty kvantových výtěžků fluorescence, které předurčují tyto materiály pro aplikace v optoelektronických a fotonických zařízeních. Tato práce popisuje přípravu nanočástic perovskitů halogenidů kovů pomocí stabilizačních činidel inspirovaných přírodou. Stabilizační činidla zde slouží nejen ke stabilizaci, ale i k modifikaci povrchu nanočástic za účelem zvýšení funkčnosti výsledných nanostruktur. Úvod práce popisuje optimalizaci přípravy nanočástic precipitační technikou za použití stabilizačních činidel; jako stabilizační činidlo byl zvolen adamantan-1-amin spolu s hexanovou kyselinou. Bylo prokázáno, že klíčový vliv na optické vlastnosti výsledných koloidních roztoků má volba rozpouštědel a teploty při precipitaci. Mimo jiné byl zkoumán vliv koncentrace prekurzorů na výslednou morfologii a optické vlastnosti nanočástic a jejich koloidních roztoků. V neposlední řadě byly nanočástice stabilizovány adamantan-1-aminem spolu s různými karboxylovými kyselinami a byly studovány optické vlastnosti a koloidní stabilita výsledných koloidních roztoků. V dalším kroku byly nanočástice perovskitů stabilizovány pomocí proetogenních aminokyselin L-lysinu and L-argininu. Takto stabilizované nanočástice vykazovaly úzká emisní spektra ve viditelné oblasti a kvantové výtěžky fluorescence dosahující hodnot téměř 100 %. Stabilizace nanočástic prostřednictvím postranních skupin aminokyselin byla prokázána navázáním chránící terc-butoxykarbonylové skupiny na -amino skupinu. Nanočástice stabilizované modifikovaným lysinem v průběhu jejich přípravy vykazovaly závislost optických vlastností na přítomnosti vody. Předpokládá se, že molekuly vody jsou schopné kontrolovat růst krystalové mřížky po navázání na prekurzory perovskitů a ovlivňovat tak výslednou velikost nanočástic, což vede k projevení kvantových jevů. Spojení nanočástic perovskitů s peptidy představuje nový typ materiálů kombinujících výjimečné optické vlastnosti se samoorganizačními a senzorickými vlastnostmi. Tento koncept byl představen přípravou nanočástic perovskitů stabilizovaných cyklo(RGDFK) pentapeptidem. Vzhledem k citlivosti peptidů na jejich byly nanočástice stabilizovány peptidovými nukleovými kyselinami, robustními analogy nukleových kyselin. Ke stabilizaci nanočástic byl připraven monomer a trimer peptidové nukleové kyseliny obsahující thymin jako dusíkatou bázi. Thymin byl na povrchu nanočástic dostupný k interakci s adeninem přes vodíkové můstky umožňující přenos náboje. Kombinace peptidových nukleových kyselin a perovskitů s unikátními optickými vlastnostmi otevírá aplikační možnosti zejména v oblasti optických senzorů.
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Role endotelinových receptorů typu A a B v modelu fokální ischemie u mláďat laboratorního potkana / The role of endothelin receptors type A and B in the model of focal cerebral ischemia in immature ratsVondráková, Kateřina January 2014 (has links)
Hypoxic-ischemic insult is a most common form of perinatal brain damage that threatens a newborn's life and can leads to permanent neurological sequelae. However, detailed aspects of the cerebral ischemia in the immature brain stay unanswered. We decide to use the model of focal cerebral ischemia induced by intrahippocampal endothelin-1 (ET-1) in 12-days-old rats. The knowledge about consequences of ET-1 induced ischemia and the role of endothelin receptors (ETA and ETB) in ischemia-induced consequences in immature brain are poor at present. Agonists and selective antagonists of the ETA and ETB receptors were used to determine the role of these receptors in the development of ischemia, changes in regional blood flow and tissue oxygenation, local changes of biochemical parameters and acute neuronal death. Our results indicates, that activation of the ETA receptors causes a strong decrease of the blood flow, induced related hypoxia and subsequent neuronal degeneration, whereas activation of ETB receptors has likely modulatory role. Moreover, ischemia causes increase of excitatory amino acids concentration, whereas inhibitory amino acid, except taurine, decreased after ischemia. These facts provides new insights in a case of perinatal ischemia. This thesis demonstrates the wide range of different effects of...
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Charakterizace a eliminace obtížně odstranitelných látek při úpravě vody / Characterisation and elimination of compounds difficult to remove during water treatmentČermáková, Lenka January 2020 (has links)
The Ph.D. thesis deals with the characterization of algal organic matter (AOM), which is difficult to remove in water treatment, and on the basis of AOM character, various methods for its elimination, e.g. coagulation, oxidation with subsequent coagulation and adsorption onto activated carbon are assesed. Special emphasis is placed on identifying the optimal conditions of the processes and on describing the mechanisms and interactions involved. In terms of anthropogenic micropollutants, the thesis deals with the highly topical issue of the occurrence of microplastics in water. It was found that the removal efficiency of the individual AOM components varies substantially depending on the elimination method used. The identified optimum conditions of individual methods and especially the mechanisms that apply to the removal of target substances varied widely. The non-proteinaceous fraction of AOM was removed with very low efficiency (max. 25%) by conventional coagulation even under optimized conditions (pH 6.6- 7.5 for aluminium sulfate as the coagulating agent and pH 7.5-9.0 for polyaluminium chloride) and it was given by the high content of low molecular weight (LMW) substances that are difficult to coagulate. The dominant coagulation mechanism was adsorption onto aluminium hydroxide precipitates....
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