Organic Phosphorus Insecticides Research Articles

Highly sensitive methyl parathion electrochemical sensor designed from expired mung bean-derived porous carbon embellished with cerium oxide nanoparticles

Methyl parathion (MP) is one kind of highly toxic, efficient, and broad-spectrum organic phosphorus insecticides, which may prevent and control various pests on crops. However, the unscientific usage of MP has caused serious harm to humans and ecological environment. It is very necessary to design a sensitive and selective MP analysis method to ensure the food safety and life health. In this work, we reported a low-cost and environmental-friendly strategy to prepare the expired mung bean derived porous carbon (EMBPC) with interconnected carbon conductive network and large specific surface area, which was further decorated by cerium oxide (CeO2) nanoparticles. EMBPC possessed good conductivity property and electrochemical active area, which effectively boosted the charge transfer efficiency. CeO2 nanoparticles with good biocompatibility and high catalytic capacity promoted the efficient adsorption of MP on the surface of sensing electrode due to the affinity of CeO2 nanoparticles towards the phosphate groups of MP. Furthermore, EMBPC with porous carbon conductive structure could effectively make up for the inherent disadvantage of CeO2 nanoparticles in the term of electrical conductivity. The fabricated EMBPC@CeO2/GCE sensor showed highly sensitive MP detection property with low limit of detection (LOD) of 9.028 nM. The satisfactory repeatability, reproducibility, and anti-interference ability could be achieved at the fabricated MP electrochemical sensor. For the detection of MP in food samples, the EMBPC@CeO2/GCE sensor showed satisfactory recovery rates of 95.25–112.31 % and low RSD of 1.76–4.05 %, which suggested the good application prospect of the EMBPC@CeO2/GCE sensor.

Antibiotics Used in Patients after Surgery and Effects of Human Serum Paraoxonase-I (PON1) Enzyme Activity.

Paraoxonase (PON; arilesterase, [EC 3.1.8.1]) is an enzyme from the group arilesterases (ARE). This enzyme is capable of hydrolyzing paraoxone which is the active metabolite of parathion, an organic phosphorus insecticide. PON activity was found to be low in individuals prone to development of atherosclerosis such as diabetes, familial hypercholesterolemia and kidney disorders. It was noted that PON enzyme activity decreases in relation to age increase in adults. PON enzyme activity is approximately half of that in newborns and premature babies. Approximately one year after birth, it reaches the adult level. It can be said that PON1 has significant role on living organisms. For this reason, many studies on interactions of PON-drugs are needed. In this article, our aim is to investigate in vitro effects of four pharmaceutically active agents (fosfomycin, cefuroxime axetil, cefaclor monohydrate, and cefixime) which are often used in patients after surgery on human serum paraoxanase-I (PON1) enzyme activity. In this article, we purify paraoxonase-I enzyme from human serum by using ammonium sulfate precipitation (in the range of 60-80%), ion exchange and gel filtration chromatography. We use electrophoresis to check the purity of the enzyme. We investigate the paraoxonase activity of the enzyme at 412 nm the inhibition effects of the active substances. Paraoxone is used as the substrate. Activity measurements arw made at different inhibitor concentrations related to inhibitor studies and % Activity- [I] graphs are drawn for drug active substances. Lineweaver-Burk graphics are used to determine the Ki constants. Finally, to determine the types of inhibition we interpret these graphs. The active agents used after surgery decreased the PON1 enzyme activity. They showed different inhibition mechanism. The inhibition mechanism of fosfomycin and cefaclor monohydrate was noncompetitive, cefixime was uncompetitive and cefuroxime axetil was a competitive inhibitor. The IC50 values for fosfomycin, cefuroxime axetil, cefaclor monohydrate, and cefixime were calculated to be 31.5 mM, 1.03 mM, 4.18 mM and 0.781 mM, respectively, and the Ki constants were determined to be 27.98 ± 12.25 mM, 2.20 ± 0.22 mM, 4.81 ± 2.25 mM and 1.12 ± 0.32 mM, respectively. The IC50 and Ki values showed that cefixime active agent has the maximum inhibition. In this study, we have detected that cefuroxime axetil inhibited competitively in vitro paraoxonase activity of this enzyme. According to this information, we thought that cefuroxime axetil linked to the active site of the enzyme. Fosfomycin and cefaclor monohydrate can be attached with amino acids out of the active site of the enzyme because they inhibit enzyme noncompetitively. Cefixime can be attached only to the enzyme-substrate complex because it inhibits enzyme uncompetitively.

A Reassessment of Topical Organic Phosphorus Insecticide Exposures and Permanent Paralysis

A Reassessment of Topical Organic Phosphorus Insecticide Exposures and Permanent Paralysis

A case of organic phosphorus insecticide poisoning that developed prolonged respiratory failure

A case of organic phosphorus insecticide poisoning that developed prolonged respiratory failure

The retention behaviour and separation of some water-soluble organophosphorus insecticides on polyester-based polyurethane foams

This paper reports the concentration of some dissolved organic phosphorus insecticides in water by open-cell polyurethane foam. The results of preliminary screening tests on the retention of the tested insecticides (Diazinon, Malathion and Chloropyrifos) by polyester foams indicated that a very high percent removal of the insecticides was obtained. The retention rate was fast and reaches equilibrium in a few minutes. The various parameters affecting the preconcentration of the tested insecticides by unloaded foam, e.g. pH, extraction media, shaking time, salt effect, flow rate, temperature and sample volumes have been optimized via the static mode of separation. The unloaded foams were employed in columns for the retention and recovery of the tested species. The sorption efficiency and the recovery of the tested compounds by the unloaded foam column were found to be up to 95.5%. The equivalent to a theoretical plate by the unloaded foam was found in the range 1.12 − 1.32 ± 0.2 mm. The sorption mechanism of the tested species by the foam is discussed. The separation of some of the tested species in a mixture was achieved. The foam membrane offers unique advantages over conventional bulk-type granular sorbents and solvent extraction in offering high flow rates, rapid, versatile, effective separation and preconcentration of different species from aqueous samples. The foam provides the advantages of being, insoluble, easily separable and non-polluting, as well as inexpensive.

除草剤の選択殺草作用機構に関する生理生化学的研究

(1) Modes of the selective action of several herbicides on plant species, especially gramineous plants, were studied from the biochemical and physiological viewpoints. Not only for agricultural practice but also for scientific interest is the selective action of hercicides one of the most important aspects of their function because various characteristic to plant species can thus be revealed. In the study, the mechanisms underlying the selectivity of herbicides were traced through investigations of their absorption by either roots or shoots of plants, translocation in plant tissues or organs, chemical transformation by plant metabolism and effects on plant metabolic systems. Contribution of each process to the selectivity was evaluated by comparing these processes among plant species. How each process limits the concentration of the active chemicals in plants as well as their affinity to action site (s) was also considered. Use of herbicides labeled with radioactive isotopes was found to extremely informative for this type of study.(2) Selectivity of propanil between rice and barnyardgrass was studied at first. By using carbonyl-14C-labeled propanil with organic phosphorus insecticides such as dipterex it was shown that the absorption was not a rate-limiting process in the selectivity. It was also shown that rice leaves hydrolysed considerably the compound to 3, 4-dichloroaniline and acid unlike barnyardgrass. Out of series on N-(3, 4-dichlorophenyl)-alkylcarboxamides and N-(chloro-substituted-phenyl)-ethylcarboxamides, only a few were found to be hydrolysed by barnyardgrass. It was concluded that barnyardgrass had arylacylamidase activity with a substrate specificity strictly limited in anilides. Solan, cypromid or CMPT were not hydrolysed by rice plants.Thiadiazolylurea derivatives such as DBTU were synthesized as potent herbicides and N-demethylation was found to be the mechanism of detoxification. Cotton seedlings whidh are very tolerant to diuron were susceptible to DBTU and lacked the N-demethylation detoxification mechanism of the latter. Substrate specificity of the demethylating enzyme from different plant species was investigated.(3) When propanil was applied at very low concentrations to roots of rice and barnyardgrass for several days, selectivity between the two species was achieved. Photosynthetic activity of barnyardgrass leaves decreased, unlike that of rice leaves. Concentration of propanil in leaves and recovery rates from the inhibition were investigated and a mechanism other than the hydrolytic degradation was proposed to account for the tolerance of rice to propanil.(4) Several examples of herbicide selectivity where either absorption or translocation was the main limiting factor were identified. Orbencarb was shown to be absorbed more by crabgrass than by wheat, suggesting that the former plant may be susceptible to the herbicide due to its enhanced absorption. Barban showed a selectivity between wheat and oat. When it was applied to intact oat leaves, protein and RNA synthesis was markedly inhibited unlike in wheat. However when it was applied to leaves that had been cut in section protein and RNA synthesis in both plant species was similarly inhibited. It was observed that thiochlormethyl was actively translocated from the roots to the shoots in susceptible plants such as tomato compared with tolerant plants such as rice or cucumber.(5) In an attempt to gain a better understanding of the specificity to herbicides of a large number of plant species, comparison between cultivated varieties was made. It was found that some of the japonica type varieties of rice were much more tolerant to simetryn than some of the indica and japonica×indica hybrid-types. The former metabolized almost 90% of the simetryn applied within 24 hours while the latter only less than 50%.(6) Effect of ambient temperature on the selectivity of simetryn was studied.

Effects of some organic phosphorus and endosulfan seed dressings on wheat

The effects on wheat of three organic phosphorus insecticides and endosulfan applied as seed dressings were tested in a field trial at rates that had shown promise for the control of larvae of Desiantha caudata, Pasc. (family Curculionidae). Endosulfan and phosalone seed dressings did not reduce grain yield. Diazinon decreased plant emergence and grain yield. Plant emergence and yield decreased with increased rates of application of methomyl and with addition of the fungicide, Demosan (R) to the methomyl seed dressings.

Feasibility of prophylaxis by oral pralidoxime. Cholinesterase inactivation by organophosphorus pesticides.

One gram of pralidoxime chloride, given three to four times a week for up to 22 weeks to 13 men, was tolerated without signs. Red blood cell cholinesterase level in these men remained consistently above the level in a placebo group with equal exposures to organic phosphorus insecticides. More than half of the men given the placebo had a reduction of red blood cell cholinesterase level below 70%, but only one of the prophylactically-treated men fell this low. Although further observations on the feasibility of prophylaxis are desirable, it appears that oral pralidoxime chloride offers promise in preventing clinical poisoning from organic phosphorus pesticides.

Respiratory exposure to organic phosphorus insecticides. Observations on effectiveness of respiratory protection in preventing poisoning from occupational exposure to parathion and 2-carbomethoxy-1-methylvinyldimethyl phosphate.

Respiratory exposure to organic phosphorus insecticides. Observations on effectiveness of respiratory protection in preventing poisoning from occupational exposure to parathion and 2-carbomethoxy-1-methylvinyldimethyl phosphate.

POISONING BY META-ISOSYSTOX IN SPRAYMEN AND IN ACCIDENTALLY EXPOSED PATIENTS

One hundred and twenty-six patients poisoned by the organic phosphorus insecticide Metaisosystox were investigated. Hiccough and extrapyramidal manifestations were noticed in some patients. Serum cholinesterase levels showed an initial fall and then a rise above normal. The fall of cholinesterase was marked in patients who were exposed for relatively long periods but not in patients accidentally exposed for short times. The rise in serum cholinesterase is thought to be a compensatory protective mechanism. Correlation between serum cholinesterase levels and symptomatology was absent in some patients but present in the majority. Cholinesterase inhibition may not be the only mechanism by which organic phosphorus compounds cause poisoning.

Flavor Evaluations of Meat from Ruelene-Treated Animals1

Selected beef cuts were evaluated to determine whether the flavor was affected when animals were treated with Ruelene® (4-tert-butyl-2-chlorophenyl methyl methylphosphoramidate) for the control of cattle grubs. The palatability evaluations were made by the Human Nutrition Research Division in cooperation with the Entomology Research Division of the U. S. Department of Agriculture. Two groups of animals were treated with Ruelene, one group with 5 sprayings and the other with 1 spraying. The yearling Hereford steers used in the tests were from Government herds near the Kerrville, Texas, area and had no previous exposure to organic phosphorus insecticides. Animals of comparable age, weight, and condition were selected for each group, and the control and treated animals were kept under identical conditions.

Oral occupational parathion poisoning treated with 2-PAM iodide (2-pyridine aldoxime methiodide).

OCCUPATIONAL poisonings in agricultural workers caused by organic phosphorus insecticides have become fairly common since the compounds were introduced. These compounds are potent cholinesterase inhibitors and produce symptoms that are due at least partly to this anticholinesterase action. Atropine has long been used in the treatment of intoxication from the organic phosphorus insecticides. It produces its action by pharmacologic blockade of the muscarinic effects of acetylcholine and as such is an incomplete antidote. With the demonstration that organic-phosphate-inhibited cholinesterase can be chemically reactivated by the use of certain hydroxamic acids or aldoxime-type compounds such reactivator therapy supplies a theoretically specific . . .

Status of Boll Weevil Resistance to Insecticides in Louisiana During 19611

Expansion of the areas in Louisiana infested with chlorinated hydrocarbon resistant boll weevils ( Anthonomus grandis Boheman) has occurred yearly since 1955, with the result that all cotton-producing areas of the State are now affected. Considerable reversion to susceptibility to the chlorinated hydrocarbon insecticides has occurred in field populations, but resistance remains at a level sufficiently great to prevent effective control with these insecticides. After 5 to 6 years of intensive use of organic phosphorus insecticides or toxaphene-DDT mixtures in certain areas, there has been no measurable change in response of the boll weevil to these insecticides. Under laboratory conditions, a 10- to 12-fold increase in the LD-50 of a boll weevil culture to toxaphene-DDT mixture was obtained in 22 generations.

The Toxicity of Organic Phosphorus Insecticides to Different Species of Warmwater Fishes

Bioassays were conducted with thirteen organic phosphorus insecticides to determine their relative toxicity to four species of fish. An extremely wide range in toxicity was found with 96-hour TLm (median tolerance limit) values ranging from 0.0052 to 610 p.p.m. Bluegills were generally the most sensitive fish, followed by guppies, fathead minnows, and then goldfish. The maximum sensitivity of the different species to particular compounds ranged from 4 to as high as 900 times the minimum. Additional experiments were conducted with some of the compounds. Larger bluegills (10 grams) were slightly more tolerant than smaller bluegills (2 grams) to Delnav, parathion, and malathion; green sunfish of similar size and largemouth bass (5 grams) were not greatly different in sensitivity from the larger bluegills. Tests of five compounds revealed that the toxicity of emulsible concentrates or wettable powders was similar to that of the technical grade material. Fathead minnow fry from 2 to 30 days old were about ten times as sensitive to Delnav as adults. However, when exposed to TEPP there was little difference in sensitivity between the fry and adults. During exposure for 15 days the toxic effect of Delnav increased about fivefold over that shown in 96 hours, but there was no additional fish mortality between 15 and 30 days.

The oximes and organophosphate poisoning.

Since the insects began fighting back in 1947,1the war against them has demanded an increasingly diversified armamentarium, and the organic phosphate insecticides have played an important part in the battle. Unfortunately, this group of compounds, an outgrowth of wartime investigation of the chemically related nerve gases, are poisonous to man as well as to insects. For toxicologic purposes, they may be roughly divided into the highly toxic group, exemplified by parathion (O,O-diethyl-O-p-nitrophenyl thiophosphate) and TEPP (tetraethyl pyrophosphate), and those with less toxicity, such as malathion (O,O-dimethyl dithiophosphate of diethyl mercaptosuccinate). The former group is used primarily for agricultural insect control, whereas the latter compound has been approved for household use as well. The incidence of human poisoning by organic phosphorus insecticides appears to be increasing in frequency. In 1957 in California3there were 229 cases of occupational disease ascribed to organic phosphate insecticides, including one

Pesticide residue control under the Food, Drug, and Cosmetic Act

Examines pesticide residue control under the Food, Drug, and Cosmetic Act, as well as several classes of pesticides, including chlorinated hydrocarbon and organic phosphorus insecticides.

Physiological Effect of Organic Phosphorus Insecticides on Several Species of Fish

Abstract Fish brain acetylcholinesterase is inhibited in vivo by organic phosphorus insecticides at concentrations of 0.1 mg/1 and lower. The degree of inhibition is a function of the concentration of the insecticide, the extent of exposure, specific chemical nature of the inhibiting substance, and fish species. Species used were largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus), golden shiner (Notemigonus crysoleucas), goldfish (Carassius auratus), and fathead minnow (Pimephales promelas). Fish removed from exposure to acetylcholinesterase-inhibiting insecticides, prior to reaching lethal limits, demonstrate the capacity for regeneration of this enzyme. The time required to regenerate the brain acetylcholinesterase to normal levels depends on the extent of the initial inhibition, the specific nature of the compound producing the inhibition, and the particular species. The curve of brain enzyme inactivation and recovery, as defined by percentage changes in normal activity, describes ...

イエバエ成虫に対する各種有機燐系殺虫剤の配合による殺虫効果について

イエバエ成虫に対する各種有機燐系殺虫剤の配合による殺虫効果について

Toxicity of Organic Phosphorus Insecticides to Horses

Tests were made on 48 horses to find the optimal dosage of some organic phosphorus insecticides for use against horse bots. (Gasterophilidae). The animals were treated with Co-Ral® ( O -(3-chloro-4-methylumbelliferone) O, O -diethyl phosphorothioate), dimethoate, DOWCO 105® ( O -methyl O -(4- tert -butyl chlorophenyl) ethylphosphoramidothioate), DOWCO 109® ( O - (4- tert butyl-2-chlorophenyl) O -methyl methylphosphoramidotioate), ronnel, Ruelene® (4- tert -butyl-2-chlorophenyl methyl methylphosphoramidate), DDVP, and Dipterex® (dimethyl 2,2,2-trichloro-1-hydroxyethyl phosphonate). The insecticides were administered by stomach tube, by feeding, and by intramuscular injection. For 7 days until sacrifice, the horses were observed frequently and checked for whole blood cholinesterase activity. Although six of the animals showed signs of toxicity during the observation period, only one showed gastrointestinal congestion at necropsy. Fourteen horses owned by cooperating ranchers were treated with Dipterex in feed, with no harmful effect. The problems of determining poisoning from phosphorus insecticides are discussed.

Oxidative metabolism of sciatic nerves of hens following insecticide poisoning

Respiration rates were determined for hen sciatic nerves using the standard Warburg manometric technique. Nerves were obtained from normal hens and from hens which had become paralyzed following the administration of an organic phosphorus insecticide. The autoxidation rates of nerves from poisoned hens were depressed by about one-third of the normal rate. The residual two-thirds activity probably represents the Schwann cell contribution. The addition of glucose, galactose, l-glutamate, and pyruvate stimulated the respiratory activity of both preparations.