Nature of N‐S bond cleavage of 2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl (di‐n‐butylaminosulfenyl) (methyl)carbamate

Abstract

The cleavage of the N-S bond in 2,3-dihydro-2,2-dimethyl-7-benzofuranyl (di-n-butylaminosulfenyl) (methyl)carbamate was examined in different buffer solutions (hydrolysis), in buffer solution containing sulfhydryl reagents (thiolysis) and on thin-layer chromatographic plates. In buffer solution and on thin-layer plates, N-S bond cleavage readily occurred to give carbofuran as a major product, with minor amounts of bis-carbofuran-N,N'-disulfide and -trisulfide. The hydrolysis reaction in buffer proceeded with first-order kinetics. Significant amounts of an unknown polar compound were obtained in buffer solution and on thin-layer plates. In the presence of excess cysteine and glutathione at pH 7.0, thiolytic N-S bond cleavage occurred with first-order kinetics to give carbofuran as the sole identifiable product. At pH 5.0, three minor products were obtained along with carbofuran.

Determination and Uptake of Carbosulfan and Carbofuran in Young Douglas Firs (Pseudotsuga menziesii Mirb.)

“…Carbosulfan was not detected in the different parts of the stem, except in some low-weight Douglas firs. As Umetsu et al (1980) reported high rates of decomposition of carbosulfan into carbofuran under acidic conditions, a study was conducted on the root system of plants sampled on the field site (pH of the soil, 5.5). Roots were washed with water, prepared, and analyzed as previously described for the stems.…”

“…The decrease in carbofuran concentration may be due a metabolic pathway of carbofuran, which cannot be the same as for a "one-dose" application since the plant is in constant contact with the carbosulfan-carbofuran complex. The age of the plant may also affect the way the plant responds to the presence of these insecticides and changes the metabolic pathways proposed by Umetsu et al (1980) and by Free and Saunders (1973).…”

An Apparent Binary Choice in Biochemistry: Mutual Reactivity Implies Life Chooses Thiols or Nitrogen-Sulfur Bonds, but Not Both

“…The rapid N-S(II) reactivity toward cellular thiols is the basis of the mechanism of action of many antibiotics (Turos et al, 2002;Turos, 2005;Revell et al, 2007;Prosen et al, 2011;Ramaraju et al, 2012;Shang et al, 2013), pesticides (Chiu et al, 1975;Umetsu et al, 1980;Fukuto et al, 1983;Wallace and Zerba, 1989), and prodrug candidates (Olbe et al, 2003;Hemenway, 2006;Hemenway et al, 2007;Nti-Addae, 2008;Proença et al, 2011;Huttunen et al, 2012). Similarly, the reactivity of N-S(II) compounds to other common functional groups found in the cell (other than thiols) is not detected, showing that the main reactivity of N-S(II) compounds in the cellular environment comes from -SH groups and not from others (alcohols, amines, carboxylic acids, etc.)…”

Synthesis and insecticidal activity of new procarbofurans

“…At all doses on all species tested, either by contact or by the systemic route, it had activity similar to that of carbofuran. This derivative retains the biological activity of the parent compound which is liberated in the insect after enzymatic cleavage of the N-S bond (Umetsu et al, 1980).…”