Leaves of Ilex aquifolium L. have been used for their therapeutic properties. In previous studies, components contained in the leaves were first isolated by various chromatographic techniques. Then, quantitation of oleanolic and ursolic acids, which are responsible for the biological and therapeutic activities of the plant, was performed by HPLC, HPTLC, and somewhat by GC-MS. Our objective was to develop a simple method that allows the identification of compounds contained in the leaves of Corsican I. aquifolium and to quantify ursolic and oleanolic acids. Leaves were successively extracted with hexane and dichloromethane. The extracts were chromatographed on silica gel and the fractions of column chromatography submitted to ¹³C-NMR analysis, following a computerized method developed in the laboratory. ¹³C-NMR allowed the identification of various triterpenes including ursolic acid and oleanolic acid. Quantitation of both acids was achieved, for the first time, by ¹H-NMR after validation of the method (accuracy, precision, linearity, limit of detection and limit of quantitation). Ursolic and oleanolic acids accounted for 55.3% and 20.8% of the dichloromethane extract, respectively. This represents 1.3% and 0.5% of the mass of dried leaves. ¹H-NMR spectroscopy appeared as a powerful tool for a rapid quantitation of biologically active compounds from I. aquifolium.

In order to get better knowledge about the volatiles produced by Xanthocyparis vietnamensis, a species recently discovered in Vietnam, its wood oil has been analyzed by a combination of chromatographic (GC, CC) and spectroscopic (GC-MS, ¹³C-NMR) techniques. Forty components that accounted for 87.9% of the oil composition have been identified. The composition is dominated by nootkatene (20.7%), 11,12,13-tri-nor-eremophil-1(10)-en-7-one (17.2%), γ-eudesmol (5.1%), nootkatone (4.7%), valencene (3.5%) and 13-nor-eremophil-1(10)-en-11-one (2.6%). The structure of two new compounds—10-epi-nor-γ-eudesmen-11-one and 12-hydroxy-isodihydroagarofuran—has been elucidated, while 11,12,13-tri-nor-eremophil-1(10)-en-7-ol is reported as a natural product for the first time. The composition of X. vietnamensis wood oil varied drastically from those of leaf oils, dominated by hedycaryol (34.4%), phyllocladene (37.8%) or by pimara-6(14)-15-diene (19.4%).

The essential oil of the roots of Ferula lutea from Tunisia, obtained by hydrodistillation was analyzed by combination of GC(FID), GC-MS and ¹³C-NMR spectroscopy. The chemical composition of root oil of this species is reported for the first time. This essential oil was characterized by a high proportion of monoterpene hydrocarbons. δ-3-Carene (72.6%) was, by far, the major component of the essential oil followed by α-pinene (5.8%), myrcene (5.1%) and α-phellandrene (4.0%). Furthermore, the isolated oil was tested for its antimicrobial activity using the disc-diffusion and the microdilution essays against six Gram-positive and five Gram-negative bacteria as well as towards eight Candida species. It was found that this oil, exhibited interesting antibacterial and anticandidal activity (MIC = 39 mg/mL against Escherichia coli ATCC 25922, MIC = 78 mg/mL against Salmonella typhimurium ATCC 13311 and MIC = 156 mg/mL against Candida albicans. The anti-acetylcholinesterase and cytotoxic effects of this oil were also evaluated in this work. Results showed that this oil exhibits a high anti-acetylcholinesterase activity (IC₅₀ = 28.56±1.87 μg/mL) and cytotoxic activity (IC₅₀ = 26.39±3.98 μg/mL) towards the cell line HT-29.

In the course of our ongoing work on the chemical characterization of Corsican olive oil, we have developed and validated a method for direct quantification of squalene using ¹³C Nuclear Magnetic Resonance (NMR) spectroscopy without saponification, extraction, or fractionation of the investigated samples. Good accuracy, linearity, and precision of the measurements have been observed. The experimental procedure was applied to the quantification of squalene in 24 olive oil samples from Corsica. Squalene accounted for 0.35–0.83% of the whole composition.

This study aimed to investigate the chemical composition of the leaf essential oil from Ivoirian Isolona dewevrei. A combination of chromatographic and spectroscopic techniques (GC(RI), GC-MS and ¹³C-NMR) was used to analyze two oil samples (S1 and S2). Detailed analysis by repetitive column chromatography (CC) of essential oil sample S2 was performed, leading to the isolation of four compounds. Their structures were elucidated by QTOF-MS, 1D and 2D-NMR as (10βH)-1β,8β-oxido-cadin-4-ene (38), 4-methylene-(7αH)-germacra-1(10),5-dien-8β-ol (cis-germacrene D-8-ol) (52), 4-methylene-(7αH)-germacra-1(10),5-dien-8α-ol (trans-germacrene D-8-ol) (53) and cadina-1(10),4-dien-8β-ol (56). Compounds 38, 52 and 53 are new, whereas NMR data of 56 are reported for the first time. Lastly, 57 constituents accounting for 95.5% (S1) and 97.1% (S2) of the whole compositions were identified. Samples S1 and S2 were dominated by germacrene D (23.6 and 20.5%, respectively), followed by germacrene D-8-one (8.9 and 8.7%), (10βH)-1β,8β-oxido-cadin-4-ene (7.3 and 8.7), 4-methylene-(7αH)-germacra-1(10),5-dien-8β-ol (7.8 and 7.4%) and cadina-1(10),4-dien-8β-ol (7.6 and 7.2%). Leaves from I. dewevrei produced sesquiterpene-rich essential oil with an original chemical composition, involving various compounds reported for the first time among the main components. Integrated analysis by GC(RI), GC-MS and ¹³C-NMR appeared fruitful for the knowledge of such a complex essential oil.

The present work describes the chemical composition and evaluates the antibacterial properties of the leaf and the flower oils from Ridolfia segetum, a traditional medicinal plant widely distributed in Tunisia. The essential oils were analysed by combination of GC, GC-MS and ¹³C NMR and 17 components, accounting for 88.7 % and 88.6 % of the oil, respectively, were identified. The oils from fresh flowers and leaves were characterized by high contents of aphellandrene (34.7 %and 47.8 %), terpinolene (23.7 and 9.0 %), p-cymene (4.8 and 8.7 %), β-phellandrene (4.8 and 7.2 %) and limonene (3.7 and 3.9 %). Five oxygenated components were isolated from the flower oil. The essential oils and isolated compounds were evaluated for their antibacterial activity using the microdilution assay resulting in the inhibition of a number of common human pathogenic bacteria as well as of some clinical and environmental isolated strains. The minimum inhibitory concentrations (MICs) varied between 1.25 and 5 mg/mL for essential oils and between 0.62 and 5 mg/mL for pure compounds and hydrocarbon fraction. The minimum bactericidal concentrations (MBCs) were 5 mg/mL for most strains and they varied between 1.25 and more than 10 mg/mL for pure compounds. The results may suggest that the essential oils of R. segetum contains compounds with antibacterial activity, and therefore can be explored as a natural preservative ingredient in food and/or pharmaceutical preparations.