scholarly journals Evidence for the Formation of Ozone (or Ozone-Like Oxidants) by the Reaction of Singlet Oxygen with Amino Acids

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
George W. Wanjala ◽  
Arnold N. Onyango ◽  
David Abuga ◽  
Calvin Onyango ◽  
Moses Makayoto
Keyword(s):  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Amino Acid ◽  
Singlet Oxygen ◽  
Oxidation Product ◽  
Alternative Hypothesis ◽  
Methionine Sulfoxide ◽  
Amino Acid Derivatives ◽  
Water Molecules ◽  
Ozone Formation

Antibodies or some amino acids, namely, cysteine, methionine, histidine, and tryptophan, were previously reported to catalyse the conversion of singlet oxygen (1O2) to ozone (O3). The originally proposed mechanism for such biological ozone formation was that antibodies or amino acids catalyse the oxidation of water molecules by singlet oxygen to yield dihydrogen trioxide (HOOOH) as a precursor of ozone and hydrogen peroxide (H2O2). However, because HOOOH readily decomposes to form water and singlet oxygen rather than ozone and hydrogen peroxide, an alternative hypothesis has been proposed; ozone is formed due to the reaction of singlet oxygen with amino acids to form polyoxidic amino acid derivatives as ozone precursors. Evidence in support of the latter hypothesis is presented in this article, in that in the presence of singlet oxygen, methionine sulfoxide (RS(O)CH3), an oxidation product of methionine (RSCH3), was found to promote reactions that can best be attributed to the trioxidic anionic derivative RS+(OOO−)CH3 or ozone.

scholarly journals Enantioselective synthesis of α-alkenyl α-amino acids via N–H insertion reactions

2016 ◽  
Vol 7 (2) ◽  
pp. 1104-1108 ◽  
Author(s):  
Jun-Xia Guo ◽  
Ting Zhou ◽  
Bin Xu ◽  
Shou-Fei Zhu ◽  
Qi-Lin Zhou
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Enantioselective Synthesis ◽  
Insertion Reaction ◽  
Amino Acid Derivatives ◽  
Insertion Reactions ◽  
Phosphoric Acids

A new highly enantioselective route to α-alkenyl α-amino acid derivatives using a N–H insertion reaction of vinyldiazoacetates and tert-butyl carbamate cooperatively catalyzed by achiral dirhodium(ii) carboxylates and chiral spiro phosphoric acids was developed.

Synthesis of New β-Amino Acids via 5-Oxazolidinones and the Arndt - Eistert Procedure

2005 ◽  
Vol 58 (11) ◽  
pp. 778 ◽  
Author(s):  
Andrew B. Hughes ◽  
Brad E. Sleebs
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Reductive Cleavage ◽  
High Yield ◽  
Amino Acid Derivatives ◽  
Peptide Therapeutics

N-Methyl β-amino acids are potentially useful amino acid derivatives for incorporation in lead peptide therapeutics. The syntheses of five such compounds are presented. Their synthesis via 6-oxazinanones was low yielding. Alternatively, reductive cleavage of a 5-oxazolidinone gave the N-methyl α-amino acid, which was then homologated via an Arndt–Eistert procedure in high yield to give the N-methyl β-amino acid.

Chiral sensors for determining the absolute configurations of α-amino acid derivatives

2018 ◽  
Vol 16 (37) ◽  
pp. 8311-8317 ◽  
Author(s):  
Zhongxiang Chen ◽  
Hongjun Fan ◽  
Shiwei Yang ◽  
Guangling Bian ◽  
Ling Song
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Derivatives ◽  
H Nmr ◽  
The Absolute

Two simple 1H NMR tests give the absolute configurations of α-amino acids.

THE OXIDATION OF ESTRONE-16-C14BY PEROXIDASE

1962 ◽  
Vol 40 (1) ◽  
pp. 459-469 ◽  
Author(s):  
P. H. Jellinck ◽  
Louise Irwin
Keyword(s):  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Amino Acid ◽  
Serum Albumin ◽  
Oxidase Activity ◽  
Water Soluble ◽  
The Other ◽  
Aerobic Incubation ◽  
Nitrogenous Compounds ◽  
Initial Generation

Aerobic incubation of estrone-16-C14with peroxidase in the presence of serum albumin and other proteins resulted in the formation of water-soluble, ether-insoluble metabolites in high percentage yields. Similar products were formed when protein was replaced by cysteine or tryptophan but none of the other amino acids tested had any effect. The evidence points to an initial generation of hydrogen peroxide from these nitrogenous compounds by the enzyme acting as an aerobic oxidase, and the subsequent peroxidation of estrone to highly reactive products. These then combine with the protein or amino acid or else undergo alternative reactions. A strong chemical bond is formed with albumin and attempts to release the estrone metabolites from it were unsuccessful. Uterine homogenates from estrogen-treated rats showing high DPNH oxidase activity contained no "peroxidase" as measured by the formation of water-soluble products from estrone in the presence of protein.

scholarly journals Nitrosation and analysis of amino acid derivatives by isocratic HPLC

RSC Advances ◽  
2016 ◽  
Vol 6 (16) ◽  
pp. 13120-13128 ◽  
Author(s):  
Songül Ulusoy ◽  
Halil Ibrahim Ulusoy ◽  
Daniel Pleissner ◽  
Niels Thomas Eriksen
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Concentration ◽  
Amino Acid Concentration ◽  
Amino Acid Derivatives ◽  
Hydroxy Acids ◽  
Isocratic Hplc

Amino acids are transformed by nitrosation with dinitrogen trioxide into their corresponding α-hydroxy acids, which are separated and analysed by HPLC, and used to quantify the original amino acid concentration in samples.

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