Inhibitor Report for: Cyanophos

A simple and rapid method was developed for measuring 10 organophosphorus pesticides (acephate, methidathion, dichlorvos, fenthion, EPN, diazinon, phenthoate, malathion, fenitrothion, and cyanophos) in the serum of acute poisoning patients by LC/MS. Following deproteinization by acetonitrile, an aliquot of the biological sample was injected into a C(18) column using 10mM ammonium formate-methanol as the mobile phase. Extraction recoveries were satisfactory and ranged between 60.0 and 108.1% in serum. The limits of detection (LODs) in serum ranged from 0.125 to 1 microg/ml, and the limits of quantitation (LOQs) ranged from 0.25 to 1.25 microg/ml. An excellent linearity was observed for these LOQs up to 8 microg/ml. Intra- and interassay precision and accuracy were satisfactory for most of the pesticides analyzed. In terms of temperature stability, of all the organophosphorus compounds analyzed, dichlorvos and malathion exhibited the most rapid degradations over 24h at room temperature. Methidathion and diazinon remained relatively stable at all temperatures during the entire 4-week testing period. The present method was successfully applied to one actual case of acute poisoning. In conclusion, this method is simple, accurate, and useful for the determination of organophosphorus pesticides and should benefit both clinical and forensic toxicology.

We investigated the stability of 14 organophosphorus insecticides: dichlorvos, fenitrothion, cyanophos, malathion, phenthoate, methidathion, dimethoate, thiometon, isoxathion, diazinon, trichlorfon, EPN, acephate and sulprofos, in fresh blood. The organophosphorus compounds, except for sulprofos, decomposed over time at 37 degrees C, with varying decomposition speed for each compound. Methyl phosphate types (dichlorvos) decomposed most rapidly, followed by methyl thiophosphate types (fenitrothion and cyanophos) and methyl dithiophosphate types (methidathion, dimethoate and thiometon). Methyl thiophosphate types decomposed faster than ethyl thiophosphate types (isoxathion and diazinon). Of the five methyl dithiophosphate type insecticides (malathion, phenthoate, methidathion, dimethoate and thiometon), the compounds with a carboxylic ester bond (malathion and phenthoate) decomposed faster than the others. Compounds left standing at 37 degrees C decomposed faster than those left standing at 4 degrees C. Temperature has a great effect on the decomposition of organophosphorus insecticides in blood. However, the order of the decomposition speeds of each compound was approximately the same at different temperatures. In cases of suspected organophosphate poisoning, it should be considered that the blood concentration of the compound might decrease during the postmortem interval.

Biomimetic oxidation mediated by three types of iron porphyrins was examined for five organophosphrus pesticides, fenitrothion (I), cyanophos (II), tolclofos-methyl (III), butamifos (IV) and fenthion (V). The major products from I-IV were the corresponding phenols and each oxon formed via a phosphoxathiirane intermediate by oxidation at the P=S moiety similarly as reported for their mammalian metabolism by cytochrome P450 enzymes. Stepwise oxidation of the methylthio sulfur via sulfoxide to sulfone, and ester cleavage and oxidative desulfuration primarily proceeded for V. Both the electron distribution of the highest occupied molecular orbital and its energy level of the pesticides calculated by MNDO-PM3 were shown to control the reaction site and rate of oxidation at sulfur atoms.

Cyanophos is commonly used in Egypt to control various agricultural and horticultural pests. It is a strong contaminant in the crop culturing environments because it is highly persistent and accumulates in the soil. This contaminant can be removed by phytoremediation, which is the use of plants to clean-up pollutants. Here we tested several several strategies to improve the effectiveness of this technology, which involved various techniques to solubilize contaminants. The phytoremediation efficiency of Plantago major L. was improved more by liquid silicon dioxide (SiO(2)) than by other solubility-enhancing agents, resulting in the removal of significant amounts of cyanophos from contaminated soil. Liquid SiO(2) increased the capacity of P. major L. to remove cyanophos from soil by 45.9% to 74.05%. In P. major L. with liquid SiO(2), leaves extracted more cyanophos (32.99 microg/g) than roots (13.33 microg/g) over 3 days. The use of solubilization agents such as surfactants, hydroxypropyl-ss-cyclodextrin (HPssCD), natural humic acid acid (HA), and Tween 80 resulted in the removal of 60 convergents of cyanophos from polluted soil. Although a batch equilibrium technique showed that use of HPssCD resulted in the efficient removal of cyanophos from soil, a greater amount of cyanophos was removed by P. major L. with SiO(2). Moreover, a large amount of cyanophos was removed from soil by rice bran. This study indicates that SiO(2) can improve the efficiency of phytoremediation of cyanophos.

A simple and rapid method was developed for measuring 10 organophosphorus pesticides (acephate, methidathion, dichlorvos, fenthion, EPN, diazinon, phenthoate, malathion, fenitrothion, and cyanophos) in the serum of acute poisoning patients by LC/MS. Following deproteinization by acetonitrile, an aliquot of the biological sample was injected into a C(18) column using 10mM ammonium formate-methanol as the mobile phase. Extraction recoveries were satisfactory and ranged between 60.0 and 108.1% in serum. The limits of detection (LODs) in serum ranged from 0.125 to 1 microg/ml, and the limits of quantitation (LOQs) ranged from 0.25 to 1.25 microg/ml. An excellent linearity was observed for these LOQs up to 8 microg/ml. Intra- and interassay precision and accuracy were satisfactory for most of the pesticides analyzed. In terms of temperature stability, of all the organophosphorus compounds analyzed, dichlorvos and malathion exhibited the most rapid degradations over 24h at room temperature. Methidathion and diazinon remained relatively stable at all temperatures during the entire 4-week testing period. The present method was successfully applied to one actual case of acute poisoning. In conclusion, this method is simple, accurate, and useful for the determination of organophosphorus pesticides and should benefit both clinical and forensic toxicology.

We investigated the stability of 14 organophosphorus insecticides: dichlorvos, fenitrothion, cyanophos, malathion, phenthoate, methidathion, dimethoate, thiometon, isoxathion, diazinon, trichlorfon, EPN, acephate and sulprofos, in fresh blood. The organophosphorus compounds, except for sulprofos, decomposed over time at 37 degrees C, with varying decomposition speed for each compound. Methyl phosphate types (dichlorvos) decomposed most rapidly, followed by methyl thiophosphate types (fenitrothion and cyanophos) and methyl dithiophosphate types (methidathion, dimethoate and thiometon). Methyl thiophosphate types decomposed faster than ethyl thiophosphate types (isoxathion and diazinon). Of the five methyl dithiophosphate type insecticides (malathion, phenthoate, methidathion, dimethoate and thiometon), the compounds with a carboxylic ester bond (malathion and phenthoate) decomposed faster than the others. Compounds left standing at 37 degrees C decomposed faster than those left standing at 4 degrees C. Temperature has a great effect on the decomposition of organophosphorus insecticides in blood. However, the order of the decomposition speeds of each compound was approximately the same at different temperatures. In cases of suspected organophosphate poisoning, it should be considered that the blood concentration of the compound might decrease during the postmortem interval.

Biomimetic oxidation mediated by three types of iron porphyrins was examined for five organophosphrus pesticides, fenitrothion (I), cyanophos (II), tolclofos-methyl (III), butamifos (IV) and fenthion (V). The major products from I-IV were the corresponding phenols and each oxon formed via a phosphoxathiirane intermediate by oxidation at the P=S moiety similarly as reported for their mammalian metabolism by cytochrome P450 enzymes. Stepwise oxidation of the methylthio sulfur via sulfoxide to sulfone, and ester cleavage and oxidative desulfuration primarily proceeded for V. Both the electron distribution of the highest occupied molecular orbital and its energy level of the pesticides calculated by MNDO-PM3 were shown to control the reaction site and rate of oxidation at sulfur atoms.