Ange Bighelli

The present study reports, for the first time, the chemical composition of the leaf essential oil (LEO) from Aspilia rudis as well as its antioxidant and anti-inflammatory activities. Analysis combining GC(RI), GC-MS and ¹³C-NMR of 36 samples identified 58 compounds representing 96.7–99.3% of the whole composition. Statistical analyses revealed chemical variability in three clusters, each composed of samples from the same sampling site. Cluster I is dominated by germacrene D (27.2 ± 2.7%), α-pinene (24.0 ± 2.9%) and (E)-β-caryophyllene (13.1 ± 1.7%), cluster II by α-pinene (38.9 ± 2.4%) and germacrene D (19.1 ± 3.6%), while the prevalent compound of cluster III is α-pinene (51.9 ± 5.3%), followed by β-pinene (11.7 ± 1.7%) and germacrene D (10.7 ± 2.2%). The oil samples S10, S26 and S36 demonstrated antioxidant activity (DPPH: EC₅₀ = 43.8 ± 1.0, 28.5 ± 1.0 and 38.8 ± 1.0 µg/mL, respectively; ABTS: TEAC = 17.16 ± 0.70, 23.35 ± 1.32 and 18.76 ± 0.64 µmol TE/mg EO, respectively) and anti-inflammatory activity through the LOX inhibition assay (IC₅₀ = 34.9 ± 1.0, 32.1 ± 1.0 and 22.2 ± 1.0 µg/mL, respectively). The activities of A. rudis LEO may be related to its main compounds and thymol, all known for their various pharmacological and biological properties, and probably to synergistic effects.

The quorum-quenching activity of essential oils (EOs) from Corsican aromatic plants was evaluated using the marine bacterium Aliivibrio fischeri as a model system. Among the eleven EOs screened, Myrtus communis EO showed significant interference with QS-regulated phenotypes (swimming motility, bioluminescence, and biofilm formation). Its activity was compared to Origanum vulgaris EO, known for its high carvacrol content and potent QS inhibition. The fractionation of M. communis EO revealed that its most polar fractions exhibited comparable levels of QS-disrupting activity. These chromatographic fractions significantly affected QS-controlled traits, indicating that minor or less volatile compounds may contribute to, or enhance, the overall bioactivity. Furthermore, M. communis EO and its polar fractions displayed stronger anti-QS effects against A. fischeri than O. vulgaris EO. These results highlight M. communis EO as a promising source of natural QS inhibitors and underscore the importance of exploring both complete EOs and their active fractions. This study supports the valorization of Mediterranean endemic flora as a reservoir of bioactive compounds, tested on a model system A. fischeri, and encourages future research on the potential of Myrtus communis against clinical bacterial isolates and the development of novel anti-virulence strategies.

Cyperus stoloniferus Retz. is a perennial grass-like plant widely distributed in Vietnam. The composition of essential oil isolated from rhizomes has been investigated by a combination of chromatographic (Column chromatography, Gas chromatography in combination with retention indices) and spectroscopic techniques (Mass spectrometry, 13C NMR spectroscopy). Cyperene (15.8%), cyperotundone (12.9%) and α-cyperone (11.2%) were the major components. The composition of essential oil sample from this species in Vietnam differed substantially from that previously reported in China. C. stoloniferus rhizome essential oil displayed weak antibacterial activity against gram-negative bacteria, gram-positive bacteria, and yeasts.

This study aims at investigating the chemical composition of root, stem and leaf essential oils from Ivorian Synedrella nodiflora, with the root oil being described for the first time. Sixty, fifty-one and forty-nine constituents were, respectively identified in the root, stem and leaf oils using a combination of GC(RI), GC-MS and ¹³C-NMR analyses. They accounted for 95.6–97.3%, 92.6–97.6% and 93.3–98.8% of the total composition, respectively. The main components of the root oil samples were γ-curcumene, (E)-β-caryophyllene, α-curcumene and curcuphenyl acetate. Three stem oil samples (S1, S2a, S3) were dominated by myrcene and limonene, while the most abundant components of sample S2b were thymol, germacrene D and β-elemene. (E)-β-caryophyllene and germacrene D were the major compounds of the leaf oil. Hierarchical cluster and principal component statistical analyses were performed and confirmed that the location does not influence the chemical composition. Group I consisted of the seven leaf oil samples, group II consisted of four stem oil samples and group III consisted of three root oil samples. The root oil composition differed considerably from the stem and leaf oil composition due to the presence of curcumene derivatives as major constituents. The leaf oil showed significant amounts of (E)-β-caryophyllene and germacrene D, while the stem oil stood out for its high myrcene, limonene and thymol contents.

Glyptostrobus pensilis (Staunton ex D. Don) K. Koch is a critically endangered species, native to southeastern China and also very locally found in Dak Lak Province, Vietnam. Essential oil isolated from leaves is a monoterpene-rich oil containing mainly limonene (33.3%), α-pinene (23.4%) and bornyl acetate (9.2%). The composition of G. pensilis wood oil is rather complex and the identification of individual components needed fractionation over column chromatography. The main components, identified by GC(RI), GC-MS and ¹³C NMR, were cedrol (29.3%), occidentalol (6.6%) and occidentalol isomer (5.9%).

Seven essential oil samples of two endemic species of Malagasy sage, Salvia sessilifolia Baker and Salvia leucodermis Baker, were investigated via GC(RI), GC-MS and ¹³C NMR spectrometry. In total, 81compounds were identified accounting for 93.5% to 98.7% of the total composition. The main constituents for the both species were (E)-β-caryophyllene (29.2% to 60.1%), myrcene (1.2% to 21.7%), α-humulene (5.2% to 19.7%), (E)-nerolidol (0.8% to 15.5%) and caryophyllene oxide (1.4% to 10.8%). Ethnobotanical survey of 46 informants revealed that decoctions of leafy twigs and chewed leaves were usually used. Due to the repeated fires, over-harvesting and grazing, the populations of S. sessilifolia and S. leucodermis are drastically fragmented. These risk factors led to threats to the habitats of the target species. Salvia sessilifolia Baker and Salvia leucodermis Baker are proposed to be classified as endangered species.

The essential oils of Oricia suaveolens and Guibourtia ehie from Southern Côte d’Ivoire were extracted by hydrodistillation then analyzed by gas chromatography in combination with retention indices [GC(RI)], gas chromatography coupled with mass spectrometry (GC-MS) and nuclear magnetic resonance of carbone-13 (¹³C NMR) And described here for the first time. A total of 42 compounds were identified in the essential oils of the leaves of G. ehie while 55, 40 and 23 components were identified in the leaves, stem bark and root bark oils of O. suaveolens, respectively. Essential oils samples were dominated by sesquiterpenes and (E)-β-caryophyllene was the major compound common to all samples: G. ehie leaf oil contained (E)-β-caryophyllene (26.9–40.8%), α-humulene (syn. α-caryophyllene) (6.7–9.7%), β-elemene (5.5–9.5%) and germacrene D (5.6–8.1%); O. suaveolens, leaf oil contained (E)-β-caryophyllene (33.5–39.3%), (E)-β-farnesene (5.9–9,3%), caryophyllene oxide (2.1–7.7%) and α-humulene (4.0–4.6%); stem bark oil contained α-humulene (38.3–45.8%) and (E)-β-caryophyllene (34.7–41.6%); root bark oil contained α-humulene (36.1–47.9%) and (E)-β-caryophyllene (34.3–43.3%). This study highlighted the abundant presence of (E)-β-caryophyllene, a phytocannabinoïd sesquiterpene with countless biological properties, in two plant species: Guibourtia ehie and Oricia suaveolens.

An experimental procedure using ¹H NMR was developed and validated to quantify 5‐hydroxymethyl‐2(5H)‐furanone, a valuable chemical synthon ((S)‐enantiomer), in a dichloromethane extract of Helleborus lividus subsp. corsicus leaves. This method, using vanillin as the internal standard, exhibited a perfect linearity of measurements (R² = 1) associated with very good accuracy (relative errors comprised between −1.62% and 4.25%) and precision (reproducibility 30.51 mg ± 0.4%). The limit of detection and the limit of quantitation have been measured at 0.14 mg and 0.59 mg, respectively. The experiment time is very short since a single analysis is at the minute level. 5‐Hydroxymethyl‐2(5H)‐furanone accounted for nearly 85% in the dichloromethane extract of H. lividus subsp. corsicus leaves (1.7% of the mass of fresh leaves). This plant represents an important and natural source of (S)‐5‐hydroxymethyl‐2(5H)‐furanone (main enantiomer; determined using a GC chiral analysis).

Three new compounds, a dihydrobenzofuran (coumaran) derivative (compound 1) and two pterocarpans (compounds 2 and 3) were isolated from a root extract of Calicotome villosa growing wild in Corsica. Their structures were elucidated using 1D and 2D NMR spectroscopy and MS/MS as 2-(1-methylethenyl)-5-hydroxy-6-carbomethoxy-2,3-dihydro-benzofuran, 4,9-dihydroxy-3-methoxy-2-dimethylallylpterocarpan, and 4,9-dihydroxy-3′,3′-dimethyl-2,3-pyranopterocarpan.

The essential oils of six endemic Malagasy Helichrysum species were investigated by GC (RI), GC–MS and ¹³C NMR spectrometry. In total, 153 compounds were identified accounting for 90.8% to 99.9% of the total composition. The main constituents were α-pinene for H. benthamii, 1,8-cineole for H. dubardii, (E)-β-caryophyllene for H. indutum, and H. bojerianum. H. diotoides essential oil was characterized by the presence of two lilac alcohols and four lilac acetates whereas H. hirtum essential oil exhibited an atypical composition with 7β-H-silphiperfol-5-ene, 7-epi-subergorgiol, and 7-epi-silphiperfol-5-en-13-oic acid as major components.