کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1231204 1495264 2013 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Stabilization of diketo tautomer of curcumin by premicellar anionic surfactants: UV–Visible, fluorescence, tensiometric and TD-DFT evidences
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Stabilization of diketo tautomer of curcumin by premicellar anionic surfactants: UV–Visible, fluorescence, tensiometric and TD-DFT evidences
چکیده انگلیسی

A newly observed UV band of aqueous curcumin, a biologically important molecule, in presence of anionic surfactants, viz., sodium dodecylsulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), and sodium dodecylsulfonate (SDSN) in buffered aqueous solutions has been studied experimentally and theoretically. The 425 nm absorption band of curcumin disappears and a new UV-band is observed at 355 nm on addition of the surfactants in the submicellar concentration range which is reversed as the surfactant concentration approaches the critical micelle concentration (CMC). The observed spectral absorption, fluorescence intensity and surface tension behavior, under optimal experimental conditions of submicellar concentration ranges of the surfactants in the pH range of 2.00–7.00, indicate that the new band is due to the β-diketo tautomer of curcumin stabilized by interactions between curcumin and the anionic surfactants. The stabilization of the diketo tautomer by submicellar anionic surfactants described here as well as by submicellar cationic surfactant, reported recently, is unique as this is the only such behavior observed in presence of submicellar surfactants of both charge types. The experimental results are in good agreement with the theoretical calculations using ab initio density functional theory combined with time dependent density functional theory (TD-DFT) calculations.

Figure optionsDownload as PowerPoint slideHighlights
► The β-diketo tautomer of curcumin is stabilized by submicellar anionic surfactant.
► A secondary salt effect indicates involvement of a proton in the interaction.
► TD-DFT results support the observed spectral characteristics of curcumin.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 104, March 2013, Pages 150–157
نویسندگان
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