New Eugenol Derivatives with Enhanced Insecticidal Activity

Abstract

Eugenol, the generic name of 4-allyl-2-methoxyphenol, is the major component of clove essential oil, and has demonstrated relevant biological potential with well-known antimicrobial and antioxidant actions. New O-alkylated eugenol derivatives, bearing a propyl chain with terminals like hydrogen, hydroxyl, ester, chlorine, and carboxylic acid, were synthesized in the present work. These compounds were later subjected to epoxidation conditions to give the corresponding oxiranes. All derivatives were evaluated against their effect upon the viability of insect cell line Sf9 (Spodoptera frugiperda), demonstrating that structural changes elicit marked effects in terms of potency. In addition, the most promising molecules were evaluated for their impact in cell morphology, caspase-like activity, and potential toxicity towards human cells. Some molecules stood out in terms of toxicity towards insect cells, with morphological assessment of treated cells showing chromatin condensation and fragmentation, which are compatible with the occurrence of programmed cell death, later confirmed by evaluation of caspase-like activity. These findings point out the potential use of eugenol derivatives as semisynthetic insecticides from plant natural products.

Biological Properties and Prospects for the Application of Eugenol—A Review

“…In their studies, Fernandez et al [ 46 ] investigated the efficacy of semisynthetic eugenol derivatives—such as O -alkylated bearing the propyl chain with hydrogen, hydroxyl, ester, chlorine, and carboxylic acid as terminals and corresponding O -alkylated oxiranes against the Sf9 ( Spodoptera frugiperda ) insect cell line. The insecticide activity of eugenol derivatives was also compared to a commercial synthetic insecticide, chlorpyrifos.…”

Tailored Functionalization of Natural Phenols to Improve Biological Activity

“…It is used in perfumeries for its pleasant fragrance, as a flavoring agent in foods, as antiseptic and disinfectant in dental products and in many other fields [ 169 ]. Eugenol can be readily functionalized through the chemical transformation of the phenolic -OH group (mainly via the classical etherification and esterification reactions) [ 170 , 171 , 172 , 173 , 174 , 175 , 176 ], on the aromatic ring (through nitration reaction or Mannich bases formation) [ 177 , 178 , 179 , 180 ], as well as on the allylic functionality, through epoxidation [ 175 ] ( Figure 2 ).…”

Cytotoxic Plant Extracts towards Insect Cells: Bioactivity and Nanoencapsulation Studies for Application as Biopesticides

“…For the assessment of viability, a resazurin-based method was used, as previously described [51]. Sf9 cells were plated at a density of 3 × 10 4 cells/well, incubated for 24 h and then exposed to the molecules under study for 24 h. After this period, a commercial solution of resazurin was added (1:10) and the kinetic reaction of fluorescence increase was monitored.…”