الانتقال الى المحتوى الأساسي

جامعة الملك عبدالعزيز

KING ABDULAZIZ UNIVERSITY

كلية العلوم

تفاصيل الوثيقة

نوع الوثيقة : مقال في مجلة دورية 
عنوان الوثيقة :
Oxidation of tyrosine by permanganate in presence of cetyltrimethylammonium bromide
Oxidation of tyrosine by permanganate in presence of cetyltrimethylammonium bromide
 
الموضوع : كيمياء 
لغة الوثيقة : الانجليزية 
المستخلص : In this paper we report the effect of cetyltrimethylammonium bromide, CTAB on the oxidative degradation of tyrosine by permanganate. The reaction rate bears a first-order dependence on the [MnO4-] under pseudo-first-order conditions (large excess of [tyrosine] for at least 10 times over [MnO4-]) in presence of 10.0 × 10-4 mol dm-3 CTAB. The effect of total [CTAB] on the reaction rate was determined. When [CTAB] was less than its critical micelle concentration (CMC) the rate constants (k) values decreased from 18.5 × 10-4 to 7.2 × 10-4 s-1. As the [CTAB] was greater than the CMC, the k values increase from 7.2 × 10-4 to 15.8 × 10-4 s-1at room temperature. The premicellar environment of CTAB strongly inhibits the reaction rate where as increase in rate constant ascribed to the incorporation of tyrosine and MnO4- in to the Stern layer of CTAB micelles. The reaction has acid-dependent and acid-independent paths and, in the former case, the zero-order kinetics with respect to [H2SO4] shifted to fractional-order at higher [H2SO4]. Experiments have been done to confirm the nature of Mn(IV) formed during the reduction of permanganate by tyrosine. The mechanism with the observed kinetics has been proposed and discussed. The presence of -OH group is responsible for the higher reactivity of tyrosine which easily transfers the proton to MnO4-. © 2009 Elsevier B.V. All rights reserved. 
ردمد : 0927-7765 
اسم الدورية : Colloids and Surfaces B: Biointerfaces 
المجلد : 76 
العدد : 1 
سنة النشر : 2010 هـ
2010 م
 
نوع المقالة : مقالة علمية 
تاريخ الاضافة على الموقع : Sunday, January 31, 2010 

الباحثون

اسم الباحث (عربي)اسم الباحث (انجليزي)نوع الباحثالمرتبة العلميةالبريد الالكتروني
Maqsood Ahmad MalikMalik, Maqsood Ahmadباحثدكتوراه 
سليمان ناصر باسهلBasahel, Suliman Naserباحثدكتوراهsbasahel@kau.edu.sa
عبدالله يوسف عبيدObaid, Abdullah Yousifباحثدكتوراهaobaid@kau.edu.sa
ظهير خانKhan, Zaheer باحثدكتوراهdrkhanchem@yahoo.com

الملفات

اسم الملفالنوعالوصف
 24965.pdf pdfAbstract

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