Matches in SemOpenAlex for { <https://semopenalex.org/work/W2477687984> ?p ?o ?g. }
Showing items 1 to 63 of
63
with 100 items per page.
- W2477687984 endingPage "797" @default.
- W2477687984 startingPage "785" @default.
- W2477687984 abstract "Abstract The zwitterionic radicals HO-ĊH-CH(COO - )NH 3 + (4a) and HO-Ċ(CH 3 )-CH(COO - )NH 3 + (4b) are the main species produced upon OH · radical attack in aqueous solutions at pH 3-7 at the amino acids serine, HO-CH 2 -CH(COO - )NH 3 + , or threonine, HO-CH(CH 3 )-CH(COO - )NH 3 + , respectively. Both radicals undergo elimination of NH 4 + ion to form the radicals O=CH-ĊH-COO - (7) or CH 3 -CO-ĊH-COO - (9) respectively. The pK a of the serine-derived cationic radical HO-ĊH-CH(COOH)NH 3 + (3a) (3a ⇄ 4a + H + ), was determined by ESR spectroscopy to 2.2 ± 0.1 at 276 K. From kinetic data the pK a (OH) of radical 4a (4a ⇄ O-ĊH-CH(COO - )NH 3 + (5a) + H + ) was calculated to 7.0. The elimination of NH 3 takes place from the ketyl radical 5a (type-B mechanism), the rate constant was calculated from kinetic data to 2.4 × 10 6 s -1 at 290 K. The half-lives of radicals 4a and 4b were measured by time-resolved conductivity changes upon pulse radiolysis, 170 ± 10 μs for 4a and 26 ± 2 μs for 4b, at 290 K and pH 5.8 . With the threonine derived radicals elimination of NH 3 takes place at the stage of the α-hydroxyalkyl radical 4b (type-A mechanism). In this series the pK a of the product radical CH 3 -CO-ĊH-COOH (8) (8 ⇄ 9 + H + ), was determined by ERS spectroscopy to 2.7 ± 0.1. The reasons for the observed mechanistic differences (type-A versus type-B decay) are discussed. As further examples for a type-B decay some preliminary data on the elimination of HF from the radicals CF 3 -Ċ(OH)-CF 3 and CF3-ĊH-OH have been added." @default.
- W2477687984 created "2016-08-23" @default.
- W2477687984 creator A5027743303 @default.
- W2477687984 creator A5054153155 @default.
- W2477687984 date "1985-10-01" @default.
- W2477687984 modified "2023-10-16" @default.
- W2477687984 title "Elimination of Ammonium Ion from the a-Hydroxyalkyl Radicals of Serine and Threonine in Aqueous Solution and the Difference in the Reaction Mechanism" @default.
- W2477687984 doi "https://doi.org/10.1515/znc-1985-11-1207" @default.
- W2477687984 hasPublicationYear "1985" @default.
- W2477687984 type Work @default.
- W2477687984 sameAs 2477687984 @default.
- W2477687984 citedByCount "24" @default.
- W2477687984 countsByYear W24776879842016 @default.
- W2477687984 countsByYear W24776879842017 @default.
- W2477687984 countsByYear W24776879842022 @default.
- W2477687984 crossrefType "journal-article" @default.
- W2477687984 hasAuthorship W2477687984A5027743303 @default.
- W2477687984 hasAuthorship W2477687984A5054153155 @default.
- W2477687984 hasConcept C121332964 @default.
- W2477687984 hasConcept C139066938 @default.
- W2477687984 hasConcept C148898269 @default.
- W2477687984 hasConcept C155647269 @default.
- W2477687984 hasConcept C178790620 @default.
- W2477687984 hasConcept C184651966 @default.
- W2477687984 hasConcept C185592680 @default.
- W2477687984 hasConcept C2776778087 @default.
- W2477687984 hasConcept C62520636 @default.
- W2477687984 hasConcept C66887884 @default.
- W2477687984 hasConcept C75473681 @default.
- W2477687984 hasConcept C93391505 @default.
- W2477687984 hasConceptScore W2477687984C121332964 @default.
- W2477687984 hasConceptScore W2477687984C139066938 @default.
- W2477687984 hasConceptScore W2477687984C148898269 @default.
- W2477687984 hasConceptScore W2477687984C155647269 @default.
- W2477687984 hasConceptScore W2477687984C178790620 @default.
- W2477687984 hasConceptScore W2477687984C184651966 @default.
- W2477687984 hasConceptScore W2477687984C185592680 @default.
- W2477687984 hasConceptScore W2477687984C2776778087 @default.
- W2477687984 hasConceptScore W2477687984C62520636 @default.
- W2477687984 hasConceptScore W2477687984C66887884 @default.
- W2477687984 hasConceptScore W2477687984C75473681 @default.
- W2477687984 hasConceptScore W2477687984C93391505 @default.
- W2477687984 hasIssue "11-12" @default.
- W2477687984 hasLocation W24776879841 @default.
- W2477687984 hasOpenAccess W2477687984 @default.
- W2477687984 hasPrimaryLocation W24776879841 @default.
- W2477687984 hasRelatedWork W2014925765 @default.
- W2477687984 hasRelatedWork W2024716555 @default.
- W2477687984 hasRelatedWork W2029831330 @default.
- W2477687984 hasRelatedWork W2033881168 @default.
- W2477687984 hasRelatedWork W2049092844 @default.
- W2477687984 hasRelatedWork W2058986864 @default.
- W2477687984 hasRelatedWork W2066185644 @default.
- W2477687984 hasRelatedWork W2081709688 @default.
- W2477687984 hasRelatedWork W2082216829 @default.
- W2477687984 hasRelatedWork W2085031349 @default.
- W2477687984 hasVolume "40" @default.
- W2477687984 isParatext "false" @default.
- W2477687984 isRetracted "false" @default.
- W2477687984 magId "2477687984" @default.
- W2477687984 workType "article" @default.