Paraoxonase (PON1) is a key enzyme in the metabolism of organophosphates. PON1 can inactivate some organophosphates through hydrolysis. PON1 hydrolyzes the active metabolites in several organophosphates insecticides as well as, nerve agents such as soman, sarin, and VX. The presence of PON1 polymorphisms causes there to be different enzyme levels and catalytic efficiency of this esterase, which in turn suggests that different individuals may be more susceptible to the toxic effect of OP exposure.
Carbamic acid is a cholinesterase or acetylcholinesterase (AChE) inhibitor. A cholinesterase inhibitor (or 'anticholinesterase') suppresses the action of acetylcholinesterase. Because of its essential function, chemicals that interfere with the action of acetylcholinesterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses, followed by muscle spasms and ultimately death. Nerve gases and many substances used in insecticides have been shown to act by binding a serine in the active site of acetylcholine esterase, inhibiting the enzyme completely. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop. Among the most common acetylcholinesterase inhibitors are phosphorus-based compounds, which are designed to bind to the active site of the enzyme. The structural requirements are a phosphorus atom bearing two lipophilic groups, a leaving group (such as a halide or thiocyanate), and a terminal oxygen.
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌物分类
对人类无致癌性（未列入国际癌症研究机构IARC清单）。
No indication of carcinogenicity to humans (not listed by IARC).
来源:Toxin and Toxin Target Database (T3DB)
毒理性
健康影响
急性接触胆碱酯酶抑制剂可能会导致胆碱能危象，表现为严重的恶心/呕吐、流涎、出汗、心动过缓、低血压、崩溃和抽搐。肌肉无力可能性增加，如果呼吸肌受到影响，可能会导致死亡。在运动神经积累的乙酰胆碱会导致神经肌肉接头处尼古丁受体的过度刺激。当这种情况发生时，可以看到肌肉无力、疲劳、肌肉痉挛、肌束震颤和麻痹的症状。当自主神经节积累乙酰胆碱时，这会导致交感系统中尼古丁受体的过度刺激。与此相关的症状包括高血压和低血糖。由于乙酰胆碱积累，中枢神经系统中尼古丁乙酰胆碱受体的过度刺激会导致焦虑、头痛、抽搐、共济失调、呼吸和循环抑制、震颤、全身无力，甚至可能昏迷。当由于乙酰胆碱过量在毒蕈碱乙酰胆碱受体上出现毒蕈碱过度刺激时，可能会出现视力障碍、胸部紧绷、由于支气管收缩引起的喘息、支气管分泌物增加、唾液分泌增加、流泪、出汗、肠蠕动和排尿的症状。对于男性和女性，在生育、生长和发育方面，某些生殖效应已被特别与有机磷农药暴露联系起来。关于生殖效应的大部分研究都是在农村地区使用农药和杀虫剂的农民中进行的。在女性中，月经周期紊乱、怀孕时间延长、自然流产、死产以及后代的一些发育效应已被与有机磷农药暴露联系起来。产前暴露与胎儿生长和发育受损有关。神经毒性效应也与有机磷农药中毒有关，在人类中导致四种神经毒性效应：胆碱能综合征、中间综合征、有机磷诱导的迟发性多发性神经病（OPIDP）和慢性有机磷诱导的神经精神障碍（COPIND）。这些综合征在急性 and 慢性暴露于有机磷农药后出现。
Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Certain reproductive effects in fertility, growth, and development for males and females have been linked specifically to organophosphate pesticide exposure. Most of the research on reproductive effects has been conducted on farmers working with pesticides and insecticdes in rural areas. In females menstrual cycle disturbances, longer pregnancies, spontaneous abortions, stillbirths, and some developmental effects in offspring have been linked to organophosphate pesticide exposure. Prenatal exposure has been linked to impaired fetal growth and development. Neurotoxic effects have also been linked to poisoning with OP pesticides causing four neurotoxic effects in humans: cholinergic syndrome, intermediate syndrome, organophosphate-induced delayed polyneuropathy (OPIDP), and chronic organophosphate-induced neuropsychiatric disorder (COPIND). These syndromes result after acute and chronic exposure to OP pesticides.
Symptoms of low dose exposure include excessive salivation and eye-watering. Acute dose symptoms include severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Hypertension, hypoglycemia, anxiety, headache, tremor and ataxia may also result.
If the compound has been ingested, rapid gastric lavage should be performed using 5% sodium bicarbonate. For skin contact, the skin should be washed with soap and water. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water. In serious cases, atropine and/or pralidoxime should be administered. Anti-cholinergic drugs work to counteract the effects of excess acetylcholine and reactivate AChE. Atropine can be used as an antidote in conjunction with pralidoxime or other pyridinium oximes (such as trimedoxime or obidoxime), though the use of '-oximes' has been found to be of no benefit, or possibly harmful, in at least two meta-analyses. Atropine is a muscarinic antagonist, and thus blocks the action of acetylcholine peripherally.
Scratch Damage in Ceramics: Role of Microstructure
摘要：
Scratch tests were conducted using a standard pyramid indenter against α‐SiAlON ceramics with different microstructures: (i) fine equiaxed grains and (ii) large elongated grains. The formation and propagation of cracks were investigated via focused ion‐beam milling, with an emphasis on the effect of microstructure on material removal. The fine equiaxed microstructure exhibited high resistance to material removal at low loads, because of its high hardness and homogeneous structure. As the load increased, radial and lateral cracks developed, resulting in large‐scale chipping. In contrast, the large elongated microstructure showed a propensity to form microcracks and microabrasion, which is characteristic of partial grain removal, at low loads. With increasing loads, however, the large elongated grains suppressed the propagation of radial and lateral cracks, and, consequently, no large‐scale chipping occurred. Implications for material design in abrasive‐wear conditions have been discussed.
[EN] NOVEL AZA-OXO-INDOLES FOR THE TREATMENT AND PROPHYLAXIS OF RESPIRATORY SYNCYTIAL VIRUS INFECTION [FR] NOUVEAUX AZA-OXO-INDOLES POUR LE TRAITEMENT ET LA PROPHYLAXIE DE L'INFECTION PAR LE VIRUS RESPIRATOIRE SYNCYTIAL
A butenoic acid compound is defined by the following formula: ##STR1## in which Z is O,S, vinylene or azomethyne, A is an alkylene and J is phenyl or etc. It is useful to treat the heart disease.
Potent arylamide derivatives as dual-target antifungal agents: Design, synthesis, biological evaluation, and molecular docking studies
作者：Yue Dong、Xinyong Liu、Yunfei An、Min Liu、Jun Han、Bin Sun
DOI：10.1016/j.bioorg.2020.103749
日期：2020.6
block the ergosterol synthesis. In this study, we designed a series of dual-target arylamides derivatives based on the analysis of active sites (SE, CYP51). Subsequently, these target compounds were synthesized, and their antifungal activity was evaluated. Most of compounds demonstrate the potentantifungal activity against multiple Candida spp. and A. fum. In particular, the antifungal activities of compounds
Electrocatalytic Tandem Synthesis of 1,3-Disubstituted Imidazo[1,5-<i>a</i>]quinolines via Sequential Dual Oxidative C(sp3)–H Amination in Aqueous Medium
作者：Peng Qian、Zicong Yan、Zhenghong Zhou、Kangfei Hu、Jiawei Wang、Zhibin Li、Zhenggen Zha、Zhiyong Wang
DOI：10.1021/acs.joc.8b03014
日期：2019.3.15
An NH4I-mediated tandem electrosynthesis of 1,3-disubstituted imidazo[1,5-a]quinolines was developed from readily available starting materials in aqueous medium, affording a variety of 1,3-disubstituted imidazo[1,5-a]quinolines with good to excellent yields.
从水介质中容易获得的起始原料开发了NH 4 I介导的串联电合成1,3-二取代的咪唑并[1,5- a ]喹啉，提供了各种1,3-二取代的咪唑并[1,5- a]。 ]喹啉具有良好或优异的收率。
Phenylureas. Part 1. Mechanism of the basic hydrolysis of phenylureas
作者：Robert Laudien、Rolf Mitzner
DOI：10.1039/b008532o
日期：2001.11.1
The mechanism of the hydrolytic decomposition of phenylureas in basic media in the pH range 12 to 14 is investigated. In this pH range a levelling of the rate–pH curve is observed as well as a change of the substituent influence on the hydrolysis rate. These experimental findings suggest the formation of an unreactive side product of the phenylurea in a parasitic side equilibrium at sufficiently high pH. The urea dissociates at the aryl–NH group to give its conjugate base. For the hydrolytic decomposition of phenylureas an addition–elimination mechanism is proposed as has been established for the alkaline hydrolysis of carboxylic acid esters and amides.
The present invention provides non-steroidal compounds of formula I which are selective modulators (i.e., agonists and antagonists) of a steroid receptor, specifically, the glucocorticoid receptor. The present invention also provides pharmaceutical compositions containing these compounds and methods for using these compounds to treat animals requiring glucocorticoid receptor agonist or antagonist therapy. Glucocorticoid receptor modulators are useful to treat diseases, such as obesity, diabetes, inflammation and others as described below. The present invention also provides intermediates and processes for preparing these compounds.
