Synthesis of Imidazol-2-yl Amino Acids by Using Cells from Alkane-Oxidizing Bacteria

ABSTRACT Sixty-one strains of alkane-oxidizing bacteria were tested for their ability to oxidize N-(2-hexylamino-4-phenylimidazol-1-yl)-acetamide to imidazol-2-yl amino acids applicable for pharmaceutical purposes. After growth with n-alkane, 15 strains formed different imidazol-2-yl amino acids identified by chemical structure analysis (mass and nuclear magnetic resonance spectrometry). High yields of imidazol-2-yl amino acids were produced by the strains Gordonia rubropertincta SBUG 105, Gordonia terrae SBUG 253, Nocardia asteroides SBUG 175, Rhodococcus erythropolis SBUG 251, and Rhodococcus erythropolis SBUG 254. Biotransformation occurred via oxidation of the alkyl side chain and produced 1-acetylamino-4-phenylimidazol-2-yl-6-aminohexanoic acid and the butanoic acid derivative. In addition, the acetylamino group of these products and of the substrate was transformed to an amino group. The product pattern as well as the transformation pathway of N-(2-hexylamino-4-phenylimidazol-1-yl)-acetamide differed in the various strains used.

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The Determination of Substituent Effects by 13C Nuclear Magnetic Resonance Spectrometry. The Effect of Solvent on CH2X Groups

Australian Journal of Chemistry ◽

10.1071/ch9850337 ◽

1985 ◽

Vol 38 (2) ◽

pp. 337

Author(s):

DAR Happer ◽

BE Steenson

Keyword(s):

Inductive Effect ◽

Chemical Shifts ◽

Substituent Effects ◽

Side Chain ◽

Polar Solvents ◽

13C Nuclear Magnetic Resonance ◽

Nuclear Magnetic Resonance Spectrometry ◽

Magnetic Resonance Spectrometry ◽

Lines Of Force

A previous study of the effect of meta- and para-CH2X substituents on the 13C n.m.r. chemical shifts of the α and β side-chain carbons of β- methoxycarbonylstyrenes (methyl cinnamates ) in ethanol has been extended to cover five additional solvents (Me2SO, Me2CO, CDCl3, CCl4 and C6H6). The results support the earlier claim that, for most substituents , the magnitudes of the substituent -induced shifts are proportional to the inductive effect of X. The major contributor to the latter appears to be the field effect generated by the C-X dipole, with the lines of force passing mainly through the molecule. In non-polar solvents, however, there is evidence that lines of force passing directly through the solvent can also influence the shifts in both the meta and para series.

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Characterization of amino acids and steroids by fluorine-19 nuclear magnetic resonance spectrometry of p-fluorobenzoyl derivatives

Analytical Chemistry ◽

10.1021/ac00279a023 ◽

1985 ◽

Vol 57 (1) ◽

pp. 76-81 ◽

Cited By ~ 7

Author(s):

M. P. Spratt ◽

Y. Meng ◽

H. C. Dorn

Keyword(s):

Amino Acids ◽

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Nuclear Magnetic Resonance Spectrometry ◽

Magnetic Resonance Spectrometry ◽

Nuclear Magnetic

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Characterization of the chemical structure of thermosetting resins by high-resolution solid-state carbon-13 nuclear magnetic resonance spectrometry

Analytica Chimica Acta ◽

10.1016/s0003-2670(00)83718-6 ◽

1986 ◽

Vol 189 ◽

pp. 117-133 ◽

Cited By ~ 12

Author(s):

Françoise Laupretre ◽

Lucien Monnerie ◽

Bertrand Bloch

Keyword(s):

Nuclear Magnetic Resonance ◽

Solid State ◽

Magnetic Resonance ◽

High Resolution ◽

Chemical Structure ◽

Thermosetting Resins ◽

Nuclear Magnetic Resonance Spectrometry ◽

Magnetic Resonance Spectrometry ◽

Nuclear Magnetic

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13C nuclear magnetic resonance study of cyclodipeptides containing 13C enriched hydrophobic amino acids

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19800482 ◽

1980 ◽

Vol 45 (2) ◽

pp. 482-490 ◽

Cited By ~ 10

Author(s):

Jaroslav Vičar ◽

François Piriou ◽

Pierre Fromageot ◽

Karel Bláha ◽

Serge Fermandjian

Keyword(s):

Amino Acids ◽

Nuclear Magnetic Resonance ◽

Nuclear Magnetic Resonance Study ◽

Coupling Constants ◽

Side Chain ◽

Amino Acid Residues ◽

Magnetic Resonance Study ◽

Side Chain Conformation ◽

13C Nuclear Magnetic Resonance ◽

Hydrophobic Amino Acids

The diastereoisomeric pairs of cyclodipeptides cis- and trans-cyclo(Ala-Ala), cyclo(Ala-Phe), cyclo(Val-Val) and cyclo(Leu-Leu) containing 85% 13C enriched amino-acid residues were synthesized and their 13C-13C coupling constants were measured. The combination of 13C-13C and 1H-1H coupling constants enabled to estimate unequivocally the side chain conformation of the valine and leucine residues.

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Effects of Amino Acid Side-Chain Length and Chemical Structure on Anionic Polyglutamic and Polyaspartic Acid Cellulose-Based Polyelectrolyte Brushes

Polymers ◽

10.3390/polym13111789 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1789

Author(s):

Dmitry Tolmachev ◽

George Mamistvalov ◽

Natalia Lukasheva ◽

Sergey Larin ◽

Mikko Karttunen

Keyword(s):

Glutamic Acid ◽

Chain Length ◽

Chemical Structure ◽

Side Chain ◽

Side Chains ◽

Side Chain Length ◽

Polyelectrolyte Brushes ◽

Grafting Density ◽

The Difference ◽

Cellulose Surface

We used atomistic molecular dynamics (MD) simulations to study polyelectrolyte brushes based on anionic α,L-glutamic acid and α,L-aspartic acid grafted on cellulose in the presence of divalent CaCl2 salt at different concentrations. The motivation is to search for ways to control properties such as sorption capacity and the structural response of the brush to multivalent salts. For this detailed understanding of the role of side-chain length, the chemical structure and their interplay are required. It was found that in the case of glutamic acid oligomers, the longer side chains facilitate attractive interactions with the cellulose surface, which forces the grafted chains to lie down on the surface. The additional methylene group in the side chain enables side-chain rotation, enhancing this effect. On the other hand, the shorter and more restricted side chains of aspartic acid oligomers prevent attractive interactions to a large degree and push the grafted chains away from the surface. The difference in side-chain length also leads to differences in other properties of the brush in divalent salt solutions. At a low grafting density, the longer side chains of glutamic acid allow the adsorbed cations to be spatially distributed inside the brush resulting in a charge inversion. With an increase in grafting density, the difference in the total charge of the aspartic and glutamine brushes disappears, but new structural features appear. The longer sides allow for ion bridging between the grafted chains and the cellulose surface without a significant change in main-chain conformation. This leads to the brush structure being less sensitive to changes in salt concentration.

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Peptide Modifications: Versatile Tools in Peptide and Natural Product Syntheses

Synlett ◽

10.1055/s-0037-1612417 ◽

2019 ◽

Vol 30 (11) ◽

pp. 1289-1302 ◽

Cited By ~ 4

Author(s):

Phil Servatius ◽

Lukas Junk ◽

Uli Kazmaier

Keyword(s):

Amino Acids ◽

Natural Product ◽

Bond Activation ◽

Bond Formation ◽

Side Chain ◽

Peptide Backbone ◽

Claisen Rearrangements ◽

The Past ◽

Allylic Alkylations ◽

Peptide Modifications

Peptide modifications via C–C bond formation have emerged as valuable tools for the preparation and alteration of non-proteinogenic amino acids and the corresponding peptides. Modification of glycine subunits in peptides allows for the incorporation of unusual side chains, often in a highly stereoselective manner, orchestrated by the chiral peptide backbone. Moreover, modifications of peptides are not limited to the peptidic backbone. Many side-chain modifications, not only by variation of existing functional groups, but also by C–H functionalization, have been developed over the past decade. This account highlights the synthetic contributions made by our group and others to the field of peptide modifications and their application in natural product syntheses.1 Introduction2 Peptide Backbone Modifications via Peptide Enolates2.1 Chelate Enolate Claisen Rearrangements2.2 Allylic Alkylations2.3 Miscellaneous Modifications3 Side-Chain Modifications3.1 C–H Activation3.1.1 Functionalization via Csp3–H Bond Activation3.2.2 Functionalization via Csp2–H Bond Activation3.2 On Peptide Tryptophan Syntheses4 Conclusion

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