Transamination Systems Research Articles

Jeffamine® ED‐600: a polyether amine donor for enzymatic transamination in organic solvent/solvent‐free medium with membrane‐assisted product extraction

AbstractBACKGROUNDAmine transaminases have been extensively used for synthesizing various pharmaceutically relevant compounds, mainly in aqueous media. However, their applications are often limited by poor substrate solubility, low productivity and difficult product separation. This paper reports the use of Jeffamine® ED‐600, a novel polyether amine donor, for the transaminase‐catalyzed synthesis of 4‐phenyl‐2‐butylamine in non‐aqueous media.RESULTSEnzymatic transamination was performed in the presence of a non‐polar organic solvent (n‐heptane), in which the selected amine donor is not soluble, thus a two‐liquid‐phase system was achieved. Coupling the reaction system with membrane‐assisted extraction resulted in simultaneous recovery of product, without any consistent contamination of the unreacted substrates. Moreover, a product yield of 60% was reached, compared with 15% without product extraction. The reaction was also successfully conducted without addition of any organic solvent, thus providing the first example of a solvent‐free transamination system. In the presence of only enzyme and substrates, up to 6‐fold higher product concentrations were achieved compared with the reaction performed in organic solvent.CONCLUSIONThe use of the Jeffamine® ED‐600 in non‐aqueous media resulted beneficial for 4‐phenyl‐2‐butylamine synthesis. Enzymatic transamination in organic solvent with membrane‐assisted product extraction enabled shifting of the equilibrium and selective product extraction. Solvent‐free transamination minimized the required volume of the reactor and minimized the environmental impact. Extension to other substrate/enzyme solvent‐free systems could open new possibilities and perspectives in transaminase‐catalyzed chiral amine synthesis. © 2019 Society of Chemical Industry

ChemInform Abstract: Progress in Asymmetric Biomimetic Transamination of Carbonyl Compounds

AbstractReview: 50 refs.

Progress in asymmetric biomimetic transamination of carbonyl compounds.

Transamination of α-keto acids with transaminases and pyridoxamine phosphate is an important process to form optically active α-amino acids in biological systems. Various biomimetic transamination systems have been developed for carbonyl compounds including α-keto acid derivatives, fluoroalkyl ketones, and unactivated ketones with chiral vitamin B6 analogues, artificial transaminase mimics, chiral nitrogen sources, and chiral catalysts. This review provides a brief summary of this area.

Potentiometric and multi-NMR studies of aluminum(III) complex with L-glutamate in acidic aqueous solutions.

Complex formation studies of L-glutamate with aluminum(III) ion were conducted in acidic aqueous solutions (pH 2.0 - 5.5) by means of pH-metric titration and multinuclear (1H, 13C and 27Al) NMR techniques. The following results were obtained: (1) Al could weakly coordinate with Glu to form various mononuclear 1:1 (AlLH2+, AlL+, AlLH(-1)) species and dinuclear 2:1 (Al2L4+) species in acidic aqueous solutions, which somewhat agreed with previous findings. (2) The multi-NMR spectra of Al-Glu and Al-Asp strongly suggest that, besides negatively charged carboxylate donors (-COO(-), -COO(-)), the amino group of Glu can participate in the binding of Al in the AlL+ and AlLH(-1) species in the case of its deprotonation, which rather agreed with the case of Al-Asp. (3) These tridentate five-+seven-membered joint chelate (-COO(-), -NH2, -COO(-)) complexes exhibit an enhanced stability, which can help to better understand the biological studies that Al-Glu could cross the erythrocyte membrane and the blood-brain barrier (BBB) and be deposited selectively in various brain regions, particularly in the cortex. It will also help to intrinsically understand the Al's role in the biological transamination system, which is a very important process in all living things.

Application of 15n-nuclear magnetic resonance (N.M.R.) spectroscopy for the study of nitrogen metabolism of a parasite: Transamination in Angiostrongylus cantonensis eggs

In an attempt to study nitrogen metabolism in a parasite, we applied 15N-nuclear magnetic resonance (N.M.R.) technology with a stable isotope, a 15N-labeled compound, for the study of the transamination system in A. cantonensis eggs, and demonstrated that 15N-aspartic acid can serve as an amino group donor for both the 2-oxoglutaric-glutamic acid and the pyruvic acid-alanine transamination systems in the eggs.

Complexing of zinc(II) in the transamination system: alpha-Ketoglutarate + alpha-alaninate forms glutamate + pyruvate.

Complexing of zinc(II) in the transamination system: alpha-Ketoglutarate + alpha-alaninate forms glutamate + pyruvate.

Culture and metabolism of Mycoplasma gallisepticum.

Gill, James W. (University of New Hampshire, Durham). Culture and metabolism of Mycoplasma gallisepticum. J. Bacteriol. 83:213-218. 1962.-Mycoplasma gallisepticum A5969, a strong-growing pleuropneumonia-like organism pathogenic for poultry, was found to be intolerant of extremes of temperature and potassium ion concentration. It ferments glucose to the benefit of cell yield, but glycolysis appears not to be essential to growth. Anaerobic growth can be maintained if pyruvate is added as a hydrogen recipient.A transamination system between glutamic acid and aspartic acid, more rapid toward the formation of aspartic acid, was found in a frozen-cell preparation. Two small peptides were observed to be produced by the organism and liberated into the medium under normal growth conditions. The composition of the peptides shows a relationship to the cell wall of certain bacteria.

A study of transamination system in Fusarium.

AusFusarium lycopersici wurde ein Enzympraparat gewonnen, welches Glutaminsaure durch Transaminierung aus α-Ketoglutarsaure bildete. Von den gepruften 20 Aminosauren dienten die folgenden als Donatoren der Aminogruppe: Tyrosin, Ornithin, Alanin, Methionin, Leucin, Isoleucin, Prolin, Phenylalanin, Tryptophan, Valin und Asparaginsaure. Das Transaminasesystem scheint nicht an Strukturen des Cytoplasmas gebunden zu sein. Die Resultate stimmen im Prinzip mit jenen uberein, welche beiNeurospora und bei Hefen gefunden wurden.

Transamination reaction, index of parenchymatous integrity

SummaryUsing the colorimetric method outlined by Cabaud, the author has studied 330 patients with miscellaneous diseases. The results agree with previous papers. The literature is discussed. Beside the well known clinical interest of the transaminase activity in the blood, many facts ask for more extensive research, particularly as far as brain and kidney diseases are concerned. Other transamination systems, as thyrosine-glutamic transaminase could prove to be of clinical interest.

Equilibria in transamination systems.

Equilibria in transamination systems.