کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1205950 965213 2008 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Characterisation by liquid chromatography coupled to electrospray ionisation ion trap mass spectrometry of phloroglucinol and 4-methylcatechol oxidation products to study the reactivity of epicatechin in an apple juice model system
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Characterisation by liquid chromatography coupled to electrospray ionisation ion trap mass spectrometry of phloroglucinol and 4-methylcatechol oxidation products to study the reactivity of epicatechin in an apple juice model system
چکیده انگلیسی

The reactivity of the (−)-epicatechin structure towards caffeoylquinic acid o-quinones was studied in an apple juice model solution. The approach consisted in considering separately the reactivities of the two phenolic moieties of an (−)-epicatechin molecule: phloroglucinol and 4-methylcatechol were chosen to represent A- and B-rings, respectively. The oxidation products were characterised by RP-HPLC coupled with electrospray ionisation Mass spectrometry (MS). The reactivities of the A- and B-rings were clearly different on the basis of the oxidation products formed. Both A- and B-rings could be involved in covalent bond formation, but electron transfers only occurred with the B-ring. Most of the (−)-epicatechin oxidation products were linked by A/B-ring linkage (“head-to-tail” intermolecular coupling). After this first dimerisation step, intramolecular reactions seemed to be favoured. Therefore, the complexity of oxidation products in apple juice does not only result from an extensive polymerisation of native phenolic compounds, but also from a multiplicity of small molecules in different oxidation states and isomeric forms.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Chromatography A - Volume 1179, Issue 2, 1 February 2008, Pages 168–181
نویسندگان
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