Insecticidal Activities of Chiral N-Trifluoroacetyl Sulfilimines as Potential Ryanodine Receptor Modulators

Abstract

This is the first report of novel chiral N-trifluoroacetyl sulfilimines during research for new environmentally benign and ecologically safe novel insecticides with new modes of action. Four series of phthalamides containing 20 new structures were designed, synthesized, and evaluated against oriental armyworm (Pseudaletia separata Walker) and diamondback moth (Plutella xylostella (L.)) for their insecticidal activities. The target compounds were established by corresponding (1)H NMR, HRMS (or elemental analysis), X-ray diffraction analysis, and optical polarimetry. Introduction of chiral N-trifluoroacetyl sulfiliminyl moieties into the new scaffolds showed that some target compounds possessed impressive activities as commercial flubendiamide. These N-trifluoroacetyl sulfilimines exhibited the sequence of activity against oriental armyworm as (Sc, Ss) ≥ (Sc, Rs) ≫ (Rc, Rs) > (Rc, Ss), in which the chiral carbon influenced the activities stronger than sulfur. For diamondback moth, compounds If, IIa, and IIc exhibited even stronger activity than flubendiamide; especially If displayed a death rate of 100% at 10(-6) mg L(-1), much better than that of flubendiamide (0% at 10(-4) mg L(-1)). Comparative molecular field analysis calculation indicated that stereoisomers with Sc configurations containing more electronegative group as COCF3 are favorable to the insecticidal activity. The present work demonstrated that chiral N-trifluoroacetyl sulfilimines can be considered as potential insect ryanodine receptor modulators. From the standpoint of molecular design, it was concluded that the conventional second methyl group in the aliphatic amido side chain of dicarboxamide might not be a requisite in our research on novel sulfiliminyl insecticides.

Formicidal activity of indole derivatives on Atta opaciceps (Borgmeier): Lethal, behavioural and locomotive effects

“…Alteration in the structure of indole and tryptamine resulted in modulation in formicidal activity. Similar results were found, in which synthetic modification of oxime, eugenol, tryptamine, monoterpenes, sulfilimines and amino acid resulted in modulation in insecticidal/larvicidal activities (Barbosa et al, 2012;Lima et al, 2015;Nguyen, Chompoo, & Tawata, 2015;Oliveira et al, 2014;Santos et al, 2011;Zhou et al, 2014).…”

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

“…Many both aryl and aliphatic N-S compounds of all valence states of sulfur find their uses in pharmacology (e.g., sulfonamide antibiotics), agriculture (e.g., sulfenamides benfuracarb and furathiocarb), and medicine (e.g., isothiazole perospirone, an antipsychotic drug), which implies sufficient water stability for them to be considered as potential biological agents in the first place. Many reactive N-S compounds such as N-S(II) sulfenamides or N-S(IV) sulfilimines are utilized as pesticides or herbicides in agriculture or considered as medicines (Beck, 1975;Casini et al, 2002;Bland et al, 2014;Zhou et al, 2014aZhou et al, , 2014bZhou et al, , 2014c and are water stable; in fact, their mode of action (if known) often involves rapid thiolysis in the presence of cellular -SH groups (Wallace and Zerba, 1989;Revell et al, 2007;Nti-Addae, 2008) (Tables 1 and 3), which implies that they are stable in the aqueous biological environment until they encounter thiols. Similarly, N-S molecules belonging to structural classes produced by life by definition have to be water stable.…”

Design, synthesis and insecticidal activity of novel analogues of flubendiamide containing alkoxyhexafluoroisopropyl groups

“…[10][11][12] Therefore, extensive efforts have been focused on the modication of these three moieties and a variety of structurally diverse novel ubendiamide analogues have been discovered. [13][14][15][16] It has been demonstrated that the hepta-uoroisopropyl group in the aromatic amine moiety (part C) is essential for high insecticidal activity and remarkably broadens the insecticidal spectrum. 17 However, the use of expensive starting material (heptauoroisopropyl iodide) and the poor stability and operational inconvenience of this reagent greatly restrict the widespread applications of ubendiamide in crop protection.…”