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京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13178号 / 論農博第2857号 / 新制||農||1061(附属図書館) / 学位論文||H30||N5100(農学部図書室) / (主査)教授 小川 順, 教授 栗原 達夫, 教授 三上 文三 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

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Fatty acid amide hydrolase (FAAH) is an enzyme that terminates the signaling role played by the lipid mediators, N- acylethanolamines (NAEs), present both in plants and animals. FAAH is responsible for NAE hydrolysis and has been extensively studied in mammalian systems and the model plant Arabidopsis thaliana; it has been reported in various organisms as well as some crop plants such as rice and Medicago truncatula. To understand the role of FAAH in diverse organisms, here we report the identification and biochemical characterization of a FAAH homolog in tomato. Previously identified and cloned candidate FAAH from tomato was expressed in Escherichia coli as a fused protein with 6X his-tag for identification. Supernatant containing recombinant FAAH showed the ability to hydrolyze NAE substrates. The optimal reaction conditions for enzyme assay and kinetic parameters for tomato FAAH were determined and effect of inhibitor on enzyme was determined. Characterization of FAAH in tomato will contribute to further understanding of NAE metabolic pathway and its implications.

As a class, amides are of great interest in biological studies and pharmaceutical application. In this work, podocarpic acid, a natural tricyclic diterpene, derived from Podocarpus species, has been employed to form a novel family of amide derivatives which will later be studied for their potential as new drug leads. Novel amide derivatives of podocarpic acid were synthesized from podocarpic acid in three steps. The first step involved methylation with dimethylsulfate to form methyl-O-methylpodocarpate. This step was followed by iodination with iodine to give iodomethyl-O-methylpodocarpate. Finally amidation with various aliphatic amides using a copper catalyst yielded four amide derivatives of podocarpic acid. However, iodomethyl-O-methylpodocarpate did not react with aromatic amides. This is perhaps because of the reduction in electrophilicity of an aromatic amide versus an aliphatic amide. Thus this research had led to the discovery of a method that is selective for the synthesis of aliphatic amide derivatives of podocarpic acid. Furthermore, five novel derivatives of podocarpic acid have been synthesized. Therefore a small library of novel compounds has been synthesized by utilizing selective methodology, that are now available for future examination of their anticancer and anti-tuberculosis properties.

<p> This thesis presents the theoretical study of the mechanisms of gas-phase formamide hydrolysis using ab initio SCF-MO calculations. Four reaction paths were considered; (i) the reaction of formamide with OH- (ii) the acid catalyzed hydrolysis with protonation on the nitrogen atom (iii) the acid catalyzed hydrolysis with protonation on the oxygen (iv) the uncatalyzed hydrolysis. An unconstrained optimization of all parameters was performed on the transition state and equilibrium structures. The intrinsic reaction coordinate was then followed down from the transition state to the reactants and products. All of the molecular geometries were obtained using the 4-31G basis set and all wavefunctions and energies were calculated at the 6-31G** level of theory. The theory of atoms in molecules was applied to each reaction to study the mechanisms of structural change along the reaction coordinate. Molecular graphs were calculated at points along the reaction coordinate and these give a detailed pictorial outline of the entire reaction sequence. The Laplacian of the charge density successfully predicts the correct site of protonation and the enhanced reactivity of protonated formamide over that of neutral formamide. Both the acid catalyzed reaction with nitrogen protonation and the base enhanced hydrolysis reactions proceed without a barrier with respect to reactants and products. The acid catalyzed hydrolysis with protonation on the oxygen atom proceeds with a moderate activation barrier whereas the neutral hydrolysis involves the passage over a very high activation barrier. The two acid catalyzed reactions are competitive with the N-protonation mechanism being more favourable from a kinetic point of view while the O-protonation mechanism is thermodynamically more favourable.</p> / Thesis / Master of Science (MSc)

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No / Mechanochemical chemoenzymatic peptide and amide bond formation catalysed by papain was studied by ball milling. Despite the high-energy mixing experienced inside the ball mill, the biocatalyst proved stable and highly efficient to catalyse the formation of α,α- and α,β-dipeptides. This strategy was further extended to the enzymatic acylation of amines by milling, and to the mechanosynthesis of a derivative of the valuable dipeptide L-alanyl-L-glutamine. / We thank RWTH Aachen University for support from the Distinguished Professorship Program funded by the Excellence Initiative of the German federal and state governments. EPSRC, grant no. EP/L019655/1.

Yes / A highly enantioselective rhodium catalysed asymmetric arylation (RCAA) of nitroolefins with arylboronic acids is presented using a newly developed, C1-symmetric, non-covalent interacted, phellandrene derived, nordehydroabietyl amide-containing chiral diene under mild conditions. Stereoelectronic effects were studied, suggesting an activation of the bound substrate through the secondary amide as a hydrogen-bond donor.

Poly(ether-b-amide) (Pebax® grade 1074) is a waterproof breathable block copolymer containing soft poly(ethylene oxide) and rigid polyamide 12 segments. Its intrinsic gas permeabilities to nitrogen, oxygen, methane, helium, hydrogen, and carbon dioxide were tested under different feed pressures (0.3 – 2.5 MPa) and temperatures (20 – 80 °C). This helps to obtain a comprehensive understanding of the polymer, because prior work reported in the literature addressed only a few gases and used inconsistent membrane preparation and test methods. Relatively high polar (or quadrupolar)/nonpolar gas selectivity were observed. CO2/N2 selectivity was demonstrated to be as high as 105±0.4 in Pebax®1074, with CO2 permeability coefficient of approximately 180±1 Barrer at room temperature. Additionally, the effects of solvent used in membrane preparation, heat treatment, membrane thickness, and polymer solution concentration on the membrane permeability were evaluated. Pebax® is a highly breathable material, thus its application as breathable chemically-resistant protective clothing was studied. Dimethyl methylphosphonate (DMMP) – a sarin simulant – was selected as the challenge agent. The liquid pervaporation of pure water (simulating perspiration) and pure DMMP were measured for Pebax®1074, Pebax®2533, nitrile, latex, poly(vinyl chloride), low density polyethylene, silicone, and silicone-polycarbonate copolymer under pervaporation mode. Pebax®1074 was not only the most water permeable material but also the most selective of all the tested materials for water/DMMP – making it a very promising material for this application.