کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4699972 | 1637690 | 2010 | 21 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Complexation of carboxyl groups in bacterial lipopolysaccharides: Interactions of H+, Mg2+, Ca2+, Cd2+, and UO22+ with Kdo and galacturonate molecules via quantum mechanical calculations and NMR spectroscopy
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Complexation of carboxyl groups in bacterial lipopolysaccharides: Interactions of H+, Mg2+, Ca2+, Cd2+, and UO22+ with Kdo and galacturonate molecules via quantum mechanical calculations and NMR spectroscopy Complexation of carboxyl groups in bacterial lipopolysaccharides: Interactions of H+, Mg2+, Ca2+, Cd2+, and UO22+ with Kdo and galacturonate molecules via quantum mechanical calculations and NMR spectroscopy](/preview/png/4699972.png)
چکیده انگلیسی
Quantum chemical calculations were combined with acid/base titrations and 13C NMR experiments to determine the structures, Gibbs free energy changes, vibrational frequencies and NMR chemical shifts characterizing the interactions of H+, Mg2+, Ca2+, Cd2+ and UO22+ with the carboxyl group of the 2-Keto-3-deoxyoctanoate (Kdo) and galacturonate molecules as models for reactive sites on bacterial surfaces. Monodentate, bidentate and outer-sphere complexation modes were considered. Results are also consistent with previous experimental and theoretical work on metal-carboxyl complexation, in particular with EXAFS studies. Among the four metals considered here, the theoretical results suggest that Mg2+ complexation is most thermodynamically favorable and UO22+ complexation is least favorable. On the other hand, our NMR experimental results suggested that Cd2+ complexation is the most favorable, whereas Mg2+ and Ca2+ complexation are weak processes, hindered by competition with H+. Apart from this discrepancy, there was a reasonable agreement between the theoretical and experimental results, which, taken together, also indicated that outer-sphere complexation was the dominant mode of complexation in our systems.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Geology - Volume 273, Issues 1â2, 30 April 2010, Pages 55-75
Journal: Chemical Geology - Volume 273, Issues 1â2, 30 April 2010, Pages 55-75
نویسندگان
P. Selvarengan, J.D. Kubicki, J.-P. Guégan, X. Châtellier,