The Inhibition of the Cholinesterase Activity of Human Blood Plasma by Neutral Phosphate Esters. II: Studies with Hexa 1-C ¹⁴ -Ethyl Tetrapolyphosphate

Insecticide Structure and Activity, Insecticidal Activity of Carbamate Cholinesterase Inhibitors

“…The order of effectiveness of ring position was p < 0 < m, both for cholinesterase inhibition and for toxicity. This, too, is in agreement with previous work involving (CH3) 3N ^-substituted phenylcarbamates (38), and seems to be a definite indication of maximum fit or orientation at the enzyme surface, as reflected in similarity of configuration to the normal substrate, probably acetylcholine (7).…”

“…With this general concept in mind, the authors selected the cholinesterase (ChE) enzyme system of insects as a starting point because of its vital function in the neural behavior of the organism and the considerable information available concerning its properties and functions (5,37). The organic phosphorus compounds such as TEPP and parathion have been shcRvn to function largely if not entirely because of their inhibition of this enzyme system (3, 77, 72, 30) by acting as preferential substrates, which when adsorbed at the active center of the enzyme are not hydrolyzed and discarded as are the choline esters, but remain fixed and effectively block the site of action of the enzyme by phosphorylation (6,7,70,24,27).…”

“…The carbamic acid esters have long been known to be highly effective inhibitors of cholinesterases, and as such they have pharmacological applications. These compounds have structural con-figurations that closely resemble the choline esters, and their inhibitory activity occurs from the resulting strong attraction to the active center of the enzyme and their much greater stability to hydrolysis (7,79). Certain of these compounds, such as physostigmine and prostigmine, are very effective inhibitors of insect cholinesterases (37).…”

Recent Progress on Cellulose‐Based Ionic Compounds for Biomaterials

“…These compounds are diversified in their chemical structures ranging from phospholipids to nucleic acids, [60] and are widely used in diverse fields, such as analytical [61] and medicinal chemistry. [62] In order to artificially introduce phosphorous into organic small molecules, a few general methods have been developed to form covalent bonds such as PC [63] and PO bonds. [64] In addition to the low molecular weight organophosphorus compounds, the introduction of phosphate groups into polysaccharides backbone is an important route to prepare diverse phosphated derivatives of polysaccharides.…”

Mode of Action of Pesticides, Metabolism of Organophosphorus Insecticides in Relation to Their Antiesterase Activity, Stability, and Residual Properties

“…The molar ratio for combination of organophosphates with cholinesterase is uncertain, as the pure enzyme has never been isolated. A mole for mole ratio was indicated with hexaethyl tetraphosphate and purified human plasma cholinesterase where acetone precipitation was used to purify the inhibited enzyme (42). However, with DFP, if a one to one ratio occurred, the equivalent weight of the reacting cholinesterase would be 63,000 for an electric eel preparation (785) and 26,000 for a human plasma preparation (739).…”