From α-nucleophiles to functionalized aggregates: exploring the reactivity of hydroxamate ion towards esterolytic reactions in micelles

Abstract

Owing to the rising threats of neurotoxic organophosphosphorus compounds, facile and efficient decontamination systems are required. Since the last few decades, the search for promising α-nucleophiles for straightforward and eco-friendly decontamination reactions using α-nucleophiles has been considerably boosted up. Among these, hydroxamic acids have been widely studied due to their potential α-nucleophilicity towards carbon and phosphorus based esters. This account summarizes our research on α-nucleophilicity of hydroxamate ions in water and micelles towards esterolytic reactions. Efforts of our group in the last few years have been collectively judged and compared with the crucial findings of researchers in the relevant field. The present article sheds light on the rich chemistry of the hydroxamate ion as a perfect candidate to degrade organophosphorus esters (i.e. nerve agents, pesticides and their simulants) in water, in micelles of conventional surfactants, and in functionalized micelles. The current report also provides an insight into the possible nature and mechanisms of these reactions. A brief account of the biological activities of hydroxamic acids that have recently spurred research in medicine against some fatal diseases has been included.

Nanomaterial-Enabled Sensors and Therapeutic Platforms for Reactive Organophosphates

“…It is because without such OP removal from the skin surface, the exposed surface serves as a depot for extended OP absorption which causes sustained toxicity [115]. Several types of decontaminants [96,[116][117][118][119][120][121] have been developed for skin decontamination that include most notably reactive skin decontamination lotion (RSDL) [122,123]. Its active ingredient consists of Dekon 139, a potassium salt of diacetyl monooxime (DAM).…”

“…Other scaffolds such as those prepared by PAM conjugation to a glucose [2] or β- Recently, several types of molecular scaffolds are designed and tested as effective chemical decontaminants for OP pesticides and nerve agents [119,121,[126][127][128]. These include α-nucleophile scaffolds prepared by conjugation with oxime [16,124], pyridinium aldoxime (PAM) [120,129,130] or hydroxamic acid (HA) [16,129,131]. Some of these have shown greater efficiency in topical decontamination of porcine skin exposed to POX ex vivo than Dekon 139 [16,124].…”

Proposed “Biosynthesis” of Primarolides A and B from a Common 2-Formylbenzophenone Precursor

“…Against this background it appears highly probable that primarolides A and B both arise from proprimarolide (16) as a common precursor as shown in Scheme 3. Regarding the pronounced nucleophilicity of hydroxamic acids [10] one can expect suberoylanilid hydroxamic acid (SAHA, 3), present as an additive, to assist as a nucleophilic catalyst in the formation of lactone rac-1. In accordance to other recent reports on the isolation of aniline-derived natural products from fungi cultured in the presence of SAHA (3) [11][12][13] one can also assume that aniline is readily formed from SAHA (3) under the action of fungal amidohydrolases.…”

Rapid cleavage of phosphate triesters by the oxime 2‐(hydroxyimino)‐N‐phenyl‐acetamide

“…A convenient approach to OP decomposition is the reaction with strong nucleophiles, such as hydroxylamine, and hydroxamic acids, which furnish insights into the development of systems suited for the detoxification of OP warfare agents. Additionally, microheterogeneous systems have been proposed for the cleavage of phosphate esters, which explore important non‐covalent effects for enhancing experimental rates.…”