γ-Radiation-induced carboxylation of pyrrolidine

1976 ◽  
Vol 29 (12) ◽  
pp. 2603 ◽  
Author(s):  
A Davison ◽  
NT Barker ◽  
DF Sangster
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Carboxylic Acid ◽  
Hydroxyl Radicals ◽  
Hydrogen Abstraction ◽  
Major Product ◽  
Amino Group ◽  
Γ Radiation ◽  
Neutral Aqueous Solution ◽  
Radiation Induced

Amino acids produced in the γ-radiation-induced carboxylation of pyrrolidine and formate in neutral aqueous solution have been studied. Two products only were found in the ratio 1 : 5.5. The minor product, proline, and the major product, pyrrolidine-3-carboxylic acid, have been characterized. Their presence indicates that the predominant site of hydrogen abstraction from pyrrolidine by radiation-generated hydroxyl radicals is β to the amino group.

The isomeric distribution of amino acids produced in γ-radiolytic carboxylation of amines

1977 ◽  
Vol 30 (4) ◽  
pp. 807
Author(s):  
A Davison ◽  
NT Barker ◽  
DF Sangster
Keyword(s):  
Amino Acids ◽  
Hydroxyl Radicals ◽  
Hydrogen Abstraction ◽  
Γ Radiation ◽  
Factors Influencing ◽  
Yield Information ◽  
Isomeric Distribution

Amino acids produced in the γ-radiation-initiated carboxylation of ethylamine, propylamine, isopropylamine, butane-1,4-diamine and pyrrolidine have been characterized. Isomeric distributions of amino acids from each amine have been determined. These distributions reflect the isomeric distribution of amine radicals present, and hence yield information on the initial site of hydrogen abstraction by radiolytically generated hydroxyl radicals. Factors influencing the sites of abstraction are discussed.

Studies of radiation-induced reactions of ethylene in aqueous solution II. Reactions in the presence of oxygen as studied by pulse radiolysis and γ -irradiation techniques

1967 ◽  
Vol 300 (1463) ◽  
pp. 443-454 ◽  
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Rate Constants ◽  
Pulse Radiolysis ◽  
Major Product ◽  
Peroxy Radicals ◽  
Ferrous Ions ◽  
Constant Composition ◽  
Γ Irradiation ◽  
Radiation Induced

The radiolysis of dilute aqueous solutions containing ethylene and oxygen has been investigated. Pulse radiolysis was used to measure the rate constants for the addition of hydroxyl radicals to ethylene, the binary decomposition of the resulting hydroxyethyl radicals and their addition to ethylene and reaction with oxygen to yield peroxy radicals. The rate constants have also been determined for the mutual interaction of the peroxy radicals and their reaction with ferrous ions. The principal products of γ -irradiation were aldehydes and organic hydroperoxides. Hydrogen peroxide was found in yields close to the molecular yield from water. The polymer produced in the absence of oxygen was not formed, and glycollaldehyde, reported as a major product by previous workers, could not be detected. At constant composition of the gas mixtures, product yields were unaffected by total pressure in the range up to 40 atm, but were strongly dependent on the proportion of oxygen. Aldehyde yields were markedly greater at pH 1.2 than in neutral solution. The influence of ferrous ions an d of added hydrogen peroxide has been determined. The pulse radiolysis and γ -irradiation experiments complement one another and show that the radiation-induced oxidation of ethylene in aqueous solution involves the same primary reactions as occur in the absence of oxygen, followed by the formation and further reactions of peroxy radicals.

γ-Radiation-Induced Interactions between Amino Acids and Glucagon

1984 ◽  
Vol 97 (1) ◽  
pp. 36 ◽  
Author(s):  
Lorna K. Mee ◽  
Hie-Joon Kim ◽  
S. James Adelstein ◽  
Irwin A. Taub
Keyword(s):  
Amino Acids ◽  
Γ Radiation ◽  
Radiation Induced

scholarly journals Reaction of Br3·2- with 2-Deoxy-D-ribose. A Preferred Attack at C-1

1978 ◽  
Vol 33 (6) ◽  
pp. 666-668 ◽  
Author(s):  
Barry J. Parsons ◽  
Dietrich Schulte-Frohlinde ◽  
Clemens von Sonntag
Keyword(s):  
Aqueous Solutions ◽  
Hydroxyl Radicals ◽  
Pulse Radiolysis ◽  
Hydrogen Abstraction ◽  
Major Product ◽  
Alternative Route ◽  
Sugar Moiety ◽  
Bromide Ions

Abstract In the photolysis of 5-bromouracil containing DNA Br atoms are expected inter mediates. In order to evaluate the possible site of attack of the Br atom at the sugar moiety of DNA the reaction of 2-deoxy-D-ribose with the Br atom (complexed with two bromide ions) was investigated. Hydroxyl radicals generated by the radiolysis of N2O saturated aqueous solutions were converted into Br3·2- radicals by 1 M bromide ions. Br3·2- reacts with 2-deoxy-D-ribose (k = 3.7 · 104M-1s-1, pulse radiolysis). The major product is 2-deoxy-D-erythro-pentonic acid (G = 2.4, γ-radiolysis). It is formed by hydrogen abstraction from C-l and oxidation of this radical by other radicals. An alternative route via the radical at C-2 is neglible. It follows that Br3·2- reacts preferentially at C-1 of 2-deoxy-D-ribose

Transformation of the Carboxyl Group of an Amino Acid to Variously Substituted Imidazoles through a Davidson-Type Heterocyclization

Synthesis ◽  
2019 ◽  
Vol 51 (09) ◽  
pp. 1961-1968 ◽  
Author(s):  
Jim Küppers ◽  
Michaela Hympánová ◽  
Tim Keuler ◽  
Andreas Schneider ◽  
Gregor Schnakenburg ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Amino Acids ◽  
Amino Acid ◽  
Carboxylic Acid ◽  
Building Blocks ◽  
Carboxyl Group ◽  
Amino Group ◽  
Combinatorial Approach ◽  
X Ray ◽  
Imidazole Derivatives

The modification of amino acids leads to valuable building blocks for the synthesis of bioactive compounds. By keeping the amino group protected, the carboxylic acid functionality can be converted in two steps into an imidazole moiety via a Davidson-like heterocyclization. This reaction allows for a combinatorial approach, in which two positions at the heterocycle can be modified. Herein, we report the synthesis of such imidazole derivatives by employing N-protected cyclohexylalanine as the starting material. Different α-halo ketones were used and two points of diversity, positions 4 and 5, were examined. The structure of the final imidazole derivatives was confirmed by three X-ray crystal structure analyses and their protease inhibiting activities were evaluated.

ChemInform Abstract: Europium(III)-N,N′-ethylenebis(L-amino acid) Complexes as New Chiral NMR Lanthanoid Shift Reagents for Unprotected α-Amino Acids in Neutral Aqueous Solution.

ChemInform ◽  
2010 ◽  
Vol 32 (28) ◽  
pp. no-no
Author(s):  
Makoto Takemura ◽  
Kazuhiro Yamato ◽  
Matsumi Doe ◽  
Masaaki Watanabe ◽  
Hiroyuki Miyake ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Complexes ◽  
Neutral Aqueous Solution ◽  
Shift Reagents
Sign in / Sign up

Export Citation Format

Share Document