Изоксатион-оксон

Description

Isoxathion-oxon is an oxygen analogue of the organophosphorus insecticide isoxathion. By structure, it is diethyl ester of phosphoric acid and 5-phenyl-3-isoxazolol: O,O-diethyl-O-(5-phenyl-1,2-oxazol-3-yl)phosphate. The only difference from the original active substance is that the sulfur atom at phosphorus is replaced by oxygen, that is, the thiophosphate group P=S is converted into phosphate P=O. The product card contains the synonym “calfosox”, derived from the trade name of isoxathione (Karfos).

Basic Attributes

• CAS No.: 32306-29-9
• Chemical formula: C13H16NO5P
• Catalog section: insecticides
• Synonyms: phosphoric acid, diethyl 5-phenyl-3-isoxazolyl ether; isoxation-oxone; calfosox
• Original active ingredient: isoxathione, CAS 18854-01-8, formula C13H16NO4PS

Origin and biological role

Oxons are formed from phosphorothioate insecticides by oxidative desulfurization - replacing sulfur with oxygen. The reaction occurs in the body of insects and mammals under the influence of enzymes of the cytochrome P450 system, as well as in the environment under the influence of oxygen, light and oxidizing agents. The toxicological significance of the transformation is fundamental: phosphorothioate itself weakly inhibits acetylcholinesterase, while its oxon is a strong inhibitor of the enzyme. It is the oxon that phosphorylates the active center of acetylcholinesterase, acetylcholine ceases to be broken down and accumulates in synapses, which causes continuous excitation of the nervous system, convulsions and death of the insect. For this reason, oxons are considered to be activated metabolites responsible for the insecticidal and toxic effects of the entire group of phosphorothioates.

Scope of application

• analytical standard for the determination of residual amounts of isoxathion and its transformation products in agricultural products, water and soil using GC-MS and HPLC-MS/MS methods
• reference substance in studies of metabolism and degradation of organophosphorus insecticides
• reagent in toxicological work on acetylcholinesterase inhibition
• reference for the validation of environmental monitoring techniques

Precautions

Oxons of phosphorothioates are more active than the parent drugs as cholinesterase inhibitors, so their handling requires measures taken for highly toxic organophosphorus compounds: work in a fume hood, gloves, safety glasses, avoiding contact with skin and inhalation of vapors. Phosphate ester is hydrolyzed by alkalis; When heated to decomposition, toxic oxides of phosphorus and nitrogen are released.

Storage and handling

Store in a tightly closed container at a low temperature, in a dry, ventilated area, separate from food and feed. Dispose of waste as hazardous, do not allow it to enter water bodies or sewers. The product is for analytical and research purposes, not intended for use as a plant protection product.