کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2009763 1066686 2011 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Single and simultaneous exposure of acetylcholinesterase to diazinon, chlorpyrifos and their photodegradation products
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم زراعت و اصلاح نباتات
پیش نمایش صفحه اول مقاله
Single and simultaneous exposure of acetylcholinesterase to diazinon, chlorpyrifos and their photodegradation products
چکیده انگلیسی

In vitro inhibition of electric eel acetylcholinesterase (AChE) by single and simultaneous exposure to organophosphorus insecticides diazinon and chlorpyrifos, and their transformation products, formed due to photoinduced degradation, was investigated. Increasing concentrations of diazinon, chlorpyrifos and their oxidation products, diazoxon and chlorpyrifos-oxon, inhibited AChE in a concentration-dependent manner. IC50 (20 min) values, obtained from the inhibition curves, were (in mol/l): (5.1 ± 0.3) × 10−8, (4.3 ± 0.2) × 10−6 and (3.0 ± 0.1) × 10−8 for diazoxon, chlorpyrifos and chlorpyrifos-oxon, respectively, while maximal diazinon concentration was lower than its IC50 (20 min). Calculated KI values, in mol/l, of 7.9 × 10−7, 9.6 × 10−6 and 4.3 × 10−7 were obtained for diazoxon, chlorpyrifos and chlorpyrifos-oxon, respectively. However, 2-isopropyl-4-methyl-6-pyrimidinol (IMP) and 3,5,6-trichloro-2-pyridinol, diazinon and chlorpyrifos hydrolysis products, did not noticeably affect the enzyme activity at all investigated concentrations. Additive inhibition effect was achieved for lower concentrations of the inhibitors (diazinon/diazoxon ⩽1 × 10−4/1 × 10−8 mol/l i.e., chlorpyrifos/chlorpyrifos-oxon ⩽2 × 10−6/3 × 10−8 mol/l), while an antagonistic effect was obtained for all higher concentrations of the organophosphates. Inhibitory power of 1 × 10−4 mol/l diazinon irradiated samples can be attributed mostly to the formation of diazoxon, while the presence of non-inhibiting photodegradation product IMP did not affect diazinon and diazoxon inhibitory efficiencies.

Figure optionsDownload as PowerPoint slideResearch highlights
► Diazoxon and chlorpyrifos-oxon are stronger AChE inhibitors than their parents compounds.
► Low thio/oxo organophosphates concentrations exhibit additive inhibition effect.
► Antagonistic effect is obtained for higher thio/oxo organophosphates concentrations.
► Non-inhibiting IMP does not affect diazinon and diazoxon inhibitory efficiencies.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Pesticide Biochemistry and Physiology - Volume 100, Issue 1, May 2011, Pages 16–22
نویسندگان
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