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.

A series of β-amino alcohols were prepared by the reaction of eugenol epoxide with aliphatic and aromatic amine nucleophiles. The synthesized compounds were fully characterized and evaluated as potential insecticides through the assessment of their biological activity against Sf9 insect cells, compared with a commercial synthetic pesticide (chlorpyrifos, CHPY). Three derivatives bearing a terminal benzene ring, either substituted or unsubstituted, were identified as the most potent molecules, two of them displaying higher toxicity to insect cells than CHPY. In addition, the most promising molecules were able to increase the activity of serine proteases (caspases) pivotal to apoptosis and were more toxic to insect cells than human cells. Structure-based inverted virtual screening and molecular dynamics simulations demonstrate that these molecules likely target acetylcholinesterase and/or the insect odorant-binding proteins and are able to form stable complexes with these proteins. Encapsulation assays in liposomes of DMPG and DPPC/DMPG (1:1) were performed for the most active compound, and high encapsulation efficiencies were obtained. A thermosensitive formulation was achieved with the compound release being more efficient at higher temperatures.

Eugenol, a natural phenolic allyl benzene that has been used as an active lead compound showing significant biological activities, including insecticidal effects on a wide variety of domestic arthropod pests, was used as the main reagent in the present work. Ester eugenol derivatives were synthesized and evaluated for their insecticidal activities against the Spodoptera frugiperda cell line. Studies of structure-based inverted virtual screening were carried out in order to identify the potential targets associated with the obtained insecticidal activity. The results indicate that the insecticide activity observed is most likely a result of the interaction of these molecules with the odorant-binding proteins and/or with acetylcholinesterase.

Eugenol-based azo dyes illustrate how bio-sourced compounds like eugenol can be transformed through synthetic processes into functional and colorful compounds. The main purpose of the present work was to develop new responsive colorimetric sensors for metal cations based on eugenol-derived azo compounds. The incorporation of the azo group into the eugenol framework allows for strong electronic interactions with metal cations, leading to distinct color changes observable to the naked eye. These azo-eugenol dyes exhibit shifts in their UV-Vis absorption spectra upon complexation with metal cations such as copper (Cu²⁺) and lead (Pb²⁺), making them effective sensors for environmental and analytical applications. The eugenol-based azo dyes were subjected to photophysical studies to understand selectivity, response time, and stability in relation to metal cations, which will be a starting point for the monitoring of toxic metal contaminants in aqueous environments.

A series of azo dyes containing eugenol, the major phenolic compound in clove (Syzygium aromaticum) essential oil, was synthesized by coupling reactions of diazonium salts of different amines based on 3-aminobenzoic acid with eugenol. The new eugenol-based azo dyes were fully characterized by the usual analytical techniques and used in preliminary reactive dyeing tests on polyamide fabric to determine the colour fastness and staining under domestic washing conditions. The results obtained revealed the potential of these dyes for applications in the textile area.

The control of insect pests and the need for increased food production due to the world population growth, together with environmental issues associated with synthetic pesticides, has stimulated the development of new and “greener” alternatives, based on natural compounds. Eugenol is a natural compound that is the major component of clove oil. It has demonstrated antimicrobial and antioxidant activity, being also a powerful insecticide. Recently, new eugenol derivatives have been developed, with some molecules displaying increased insecticide activity. One of the difficulties associated with the rational development of new eugenol derivatives with enhanced insecticidal activity lies in the lack of knowledge of the specific protein target responsible for its activity and to the binding conformation of these molecules. Here, we report the application of an integrated molecular modeling—inverted virtual screening protocol of a collection of eugenol derivatives with confirmed insecticide activity against a molecular library of protein targets typically associated with the insecticide activity of natural compounds. The protocol included six different scoring functions from popular docking software alternatives. The results consistently show a marked preference for interaction of the eugenol derivatives with the odorant binding proteins (OBPs) in insect species. Interestingly, OBPs have been regarded as promising targets in the insect periphery nerve system for environmental-friendly approaches in insect pest management. The present results provide clues for the rational development of new eugenol derivatives as bioinsecticides targeting OBPs.