Natural products extracted from plants has been recognized as the most efficient starting materials to synthesize new derivatives of medicinal interest. Our research focuses on the isolation and characterization of sesquiterpene derivatives from Dittrichia Viscosa (L), as well as their hemisynthesis. To that end, a phytochemical study of Dittrichia viscosa leaves was conducted in order to obtain a sesquiterpenoid, α -Costic acid, which will be further transformed to γ -Costic acid with high yield using simple processes. Optimized molecular geometry and vibrational frequencies of both products were computed using the density functional theory. In addition, the antibacterial activity of isolated and hemisynthesized products were analyzed in vitro against Escherichia coli resistant to β-lactamase 616, Pseudomonas aeruginosa, and Staphylococcus aureus. The obtained compounds were investigated by in silico biological method to evaluate their potential inhibitory activity against same strains using FtsA, LasR proteins and DNA polymerase III enzyme. Graphical Abstract

Eugenol, a plant bioactive component, is frequently found in a variety of medicinal plants with well-defined functional attributes. Essential oils containing eugenol were extracted from buds of Eugenia caryophyllata commonly named clove using hydrodistillation. Afterwards, the analysis of the essential oils using gas chromatography/mass spectrometry (GC/MS) shows that eugenol is the major constituent with 70.14% of it. The alkene group in eugenol was epoxidised using m-chloroperbenzoic acid leading to the synthesis of epoxide eugenol. The epoxide ring was cleaved to vanillyl glycol by mixed the epoxide eugenol with aluminum chloride hydrate in an ethanolic medium. A Density Functional Theory (DFT) study was investigated to understand the reactivity of the epoxide eugenol with the aluminum chloride hydrate. The results obtained from DFT based reactivity descriptors were in good agreement with the experiment results. Graphical Abstract

This study aimed to assess the chemical composition and antibacterial potential of essential oils (EOs) from two plants: clove buds (Syzygium aromaticum) and fennel seeds (Foeniculum vulgare) EOs. The major compounds, eugenol and estragole, were isolated from these oils and tested against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The EOs were obtained via hydrodistillation and analyzed using Gas Chromatography–Mass Spectrometry (GC-MS). Clove oil was found to be rich in eugenol (68.51%), while fennel seed oil was dominated by estragole (93.30%). Antibacterial activity, assessed by the agar disc diffusion method and supported by MIC/MBC testing, revealed that eugenol exhibited the highest efficacy, with MIC values ranging from 0.58 to 1.15 mg/mL and MBC values from 1.15 to 2.30 mg/mL, particularly against S. aureus and P. aeruginosa. In silico analysis was conducted to evaluate pharmacokinetics, toxicity, and molecular docking interactions. ADME predictions indicated good oral bioavailability and high membrane permeability for both compounds, with eugenol displaying superior solubility and better compliance with Lipinski’s Rule of Five. Molecular docking simulations confirmed the antibacterial potential, with eugenol showing stronger binding affinities to bacterial targets (−7.8 kcal/mol), forming more stable and diverse interactions compared to estragole. However, toxicity predictions indicated potential mutagenic, carcinogenic, and cardiotoxic (hERG inhibition) risks for both compounds.