Reaction of epoxides with 4-nitrothiophenol. Its possible application for trapping and characterization of epoxides

Abstract

In summary, it appears that the combination of ammonia, sulfur dioxide, high moisture content, low atmospheric temperature, and low stack temperature is necessary for formation of the detached plume. Ammonium sulfate in the stack is responsible for the 10% in-stack opacity, while a secondary reaction involving sulfur dioxide and ammonia in condensed water droplets (forming ammonium sulfoxide salts and sulfuric acid) is responsible for the high-opacity detached plume. This mechanism is consistent with the dissipation of the plume as the ambient temperature increases in that it allows the plume to be diluted before water droplets can condense.

Biocatalytic Epoxidation for Green Synthesis

“…Another chromophore for the analysis of epoxidation activity is p-nitrothiophenolate (pNTP), a yellow colorimetric reagent exhibiting absorbance maxima at 405 nm. The reaction between pNTP and epoxides results in a colorless product and a related linear decrease in absorbance at 405 nm (Scheme 13.16b) [150]. Compared with NBP assay, pNTP assay displays a clear advantage in technical simplicity, as some heating and cooling procedures are not required.…”

A Screening System for the Directed Evolution of Epoxygenases: Importance of Position 184 in P450 BM3 for Stereoselective Styrene Epoxidation

“…Here we report a novel, validated, and product‐based screening system using the colorimetric agent p ‐nitrothiophenolate (pNTP) for the directed evolution of epoxygenases. pNTP is a yellow chromophore that reacts with an epoxide through nucleophilic attack, resulting in ring opening and a colorless product 15. As a model system, we chose styrene and monooxygenase P450 BM3 (BM3) 11.…”

Enlightening the Path to Protein Engineering: Chemoselective Turn-On Probes for High-Throughput Screening of Enzymatic Activity

“…They are mostly based on the conversion of epoxides to aldehydes, thiols, or diols and the application of aldehyde-, thiol-, or diol- detection methods. Detection might be complicated by instability ( e.g ., to hydrolysis), side reactions, , and volatility. ,, Epoxides can undergo reactions with hemoglobin or nucleic acids and are therefore associated with mutagenicity, carcinogenicity, and genotoxicity (Figure ).…”