Kinetics of the reaction of the first metabolite of fenitropan with some low molecular weight thiols

G. Gullner, Gyula Josepovits, Gyula Mikite

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

2‐Nitro‐I‐phenylpropen‐3‐yl acetate (NPPA), the first metabolite of the fungicide fenitropan, reacted readily with glutathione in aqueous ethanol solutions at room temperature, producing at least two products. The first reaction step, which is believed to be a bimolecular nucleophilic (Michael) addition, had a strongly pH‐dependent reaction rate. Second‐order rate constants were calculated for the reactions of NPPA at pH 4 with glutathione and with some other low molecular weight thiols. Nucleophilic reactivity of the reacting thiolate anions is linearly related to the pKa values of the thiols. However, as the concentration of thiolate anion is also determined by the thiol pKa, there is no simple relationship between second‐order rate constants and thiol pKa. Thus the blocking rate of the various essential sulphydryl groups in fungi by NPPA is determined by the sulphydryl pKa values and the ambient pH value.

Original languageEnglish
Pages (from-to)253-259
Number of pages7
JournalPesticide Science
Volume26
Issue number3
DOIs
Publication statusPublished - 1989

Fingerprint

reaction kinetics
thiols
Sulfhydryl Compounds
Molecular Weight
molecular weight
metabolites
anions
Anions
Glutathione
glutathione
fungicides
ambient temperature
Acetates
Fungi
Ethanol
acetates
ethanol
fungi
Temperature
N-propionylprocainamide

ASJC Scopus subject areas

  • Applied Microbiology and Biotechnology

Cite this

Kinetics of the reaction of the first metabolite of fenitropan with some low molecular weight thiols. / Gullner, G.; Josepovits, Gyula; Mikite, Gyula.

In: Pesticide Science, Vol. 26, No. 3, 1989, p. 253-259.

Research output: Contribution to journalArticle

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