Linked Life Data

16901112

Source:http://linkedlifedata.com/resource/pubmed/id/16901112

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2006-8-11
pubmed:abstractText
A kinetic and thermodynamic investigation of phenols para-substituted with thiyl (SR), sulfinyl (SOR), and sulfonyl (SO(2)R) groups and ortho-substituted with thiyl groups is reported. The effect of the sulfur substituents on the O-H bond dissociation enthalpy values, BDE(O-H), was measured by means of the EPR radical equilibration technique and the reactivity toward peroxyl radicals, k(inh), of these phenolic antioxidants was determined by inhibited autoxidation studies. An inverse correlation between these two parameters was found. A p-SMe substituent decreased the BDE(O-H) value to a lesser extent than a p-OMe group (-3.6 vs -4.4 kcal/mol), whereas the effect of the same groups in an ortho position showed an opposite trend (-0.85 vs -0.2 kcal/mol). The latter result is explained in terms of the different strength of the intramolecular hydrogen bond between the OH proton and the sulfur or oxygen substituents in ortho derivatives. ESI-MS analysis of the products formed by reacting the sulfides with peroxyl radicals from the azoinitiator AIBN revealed the formation of a complex mixture of products, which may play an important role in determining the overall antioxidant activity of the parent compounds.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-3263
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
71
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6325-32
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Electronic and hydrogen bonding effects on the chain-breaking activity of sulfur-containing phenolic antioxidants.
pubmed:affiliation
Dipartimento di Chimica Organica A. Mangini, Università di Bologna, Via S. Donato 11, 40126 Bologna, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't