Dominique de Rocca Serra

Chemical variability of peel and leaf essential oils of 15 species of mandarins.

Peel and leaf oils of 58 mandarin cultivars, belonging to 15 different species were obtained from fruits and leaves collected on mandarin-trees submitted to the same pedoclimatic and cultural conditions. Their chemical composition was investigated by capillary GC, GC/MS and 13C NMR and the results were submitted to a cluster analysis and a discriminant analysis. Three major chemotypes, limonene, limonene/gamma-terpinene and linalyl acetate/limonene, were distinguished for peel oils while three other chemotypes, sabinene/linalool, gamma-terpinene/linalool and methyl N-methylanthranilate, were observed for leaf oils.

Chemical variability of peel and leaf essential oils of mandarins from Citrus reticulata Blanco

Abstract Peel and leaf oils of 41 mandarin cultivars, belonging to the Citrus reticulata Blanco species, were obtained from fruits and leaves collected on mandarin trees submitted to the same pedoclimatic and cultural conditions. Their chemical composition was investigated by capillary GC, GC/MS and 13 C NMR and the results were submitted to a cluster analysis and a discriminant analysis. Two major chemotypes, limonene and limonene/ γ -terpinene, were distinguished for peel oils while three major chemotypes, sabinene/linalool, linalool/ γ -terpinene and methyl N-methylanthranilate, were observed for leaf oils.

Antibacterial action of essential oils from corsica

Abstract The antimicrobial activity of 28 essential oil samples isolated from local plants or plants cultivated in Corsica was evaluated against a large panel of human pathogenic bacteria, including Campylobacter jejuni which appeared as a good model for this purpose. The chemical composition of the 18 oils selected for their efficiency was determined by GC and GC/MS. Among them, the oils of Cistus ladaniferus, Crithmum maritimum, Daucus carota, Juniperus communis, Mentha aquatica and Santolina corsica showed compositions without components known as active, suggesting the presence of compounds not previously described as antibacterial agents.

Chemical variability of peel and leaf essential oils of sour orange

Peel and leaf oils of 30 sour orange cultivars, belonging to four different species (C. aurantium L., C. myrtifolia Raf., C. natsudaidai Hay. and C. neo-aurantium Tan.) were obtained from fruits and leaves collected on sour orange trees submitted to the same pedoclimatic and horticultural conditions. Their chemical composition was investigated by capillary GC, GC–MS and 13C-NMR. Two chemotypes, limonene and limonene/β-pinene, were distinguished for peel oils, while four chemotypes, linalool/linalyl acetate, sabinene/(E)-β-ocimene, limonene/β-pinene and β-pinene/linalool, were observed for leaf oils. Copyright

Chemical composition of peel and leaf essential oils of Citrus medica L. and C. limonimedica Lush.

Five peel oils and six leaf oils of different varieties of citrons (Citrus medica and C. limonimedica) were obtained from fruits and leaves collected on trees submitted to the same pedoclimatic and cultural conditions. Their composition was investigated by capillary GC, GC–MS and Carbon-13 NMR. Three chemotypes: limonene, limonene/γ-terpinene and limonene/geranial/neral were observed for peel oils while leaf oils exhibited the limonene/geranial/neral composition. Copyright

Composition and antimicrobial activity of the essential oil of Acronychia pedunculata (L.) Miq. from Vietnam

The chemical composition and the antimicrobial activity of the essential oil isolated from aerial parts of Acronychia pedunculata (L.) Miq. from Vietnam are reported. Analysis was carried out by GC (RI), GC–MS and 13C NMR. Thirty-four compounds were identified, accounting for 92.8% of the oil. The major constituents were α-pinene (57.4%) and (E)-β-caryophyllene (13.6%). The essential oil of A. pedunculata was shown to possess a broad spectrum of antimicrobial activity against various bacteria, particularly Salmonella enterica and Staphylococcus epidermidis.

Chemical composition of the essential oils from the aerial parts of two Malagasy endemic species (Apiaceae): Billburttia capensoides Sales & Hedge and Billburttia vaginoides Sales & Hedge

Abstract The chemical composition of twenty-five essential oil samples from the aerial parts of two Malagasy endemic species Billburttia capensoides Sales & Hedge and B. vaginoides Sales & Hedge, were investigated for the first time. Based on chromatographic profiles, three selected samples were investigated using GC(RI), GC-MS and 13C NMR. The content of the main components varied drastically from sample to sample: p-mentha-1,3,8-triene (0.2–52.7%), terpinolene (2.8–40.7%) and dill apiole (0.0–22.2%). Statistical analysis of the 25 oil compositions allowed the distinction of two well-differentiated groups. Samples of group I contained mainly p-mentha-1,3,8-triene while the Group II was dominated by terpinolene and dill apiole.

Anti-Quorum Sensing Activity of 12 Essential Oils on chromobacterium violaceum and Specific Action of cis-cis-p-Menthenolide from Corsican Mentha suaveolens ssp. Insularis

Quorum sensing (QS) is a bacterial communication mechanism used to express various survival or virulence traits leading to enhanced resistance. Chromobacterium violaceum is a commonly used strain that highlights anti-QS action of bioactive substances. Here, we wanted to see if 12 selected essential oils (EO) could exert anti-QS activity. We measured the sublethal minimal QS inhibitory concentration (MQSIC) by assessing violacein production of C. violaceum along with bacterial growth. To confirm the QS disruption, we also proceed to surface bacterial observations using scanning electron microscopy (SEM). We showed that cis-cis-p-menthenolide extracted and isolated from a plant endemic to occidental Mediterranean Sea islands, Mentha suaveolens ssp. insularis, acts as an inhibitor of violacein production and biofilm formation. Measured MQSIC was much lower than the minimal inhibitory concentration (MIC): 0.10 mg·mL−1 vs. 3.00 mg·mL−1. Moreover, disturbance of QS-related traits was confirmed by the degradation of C. violaceum biofilm matrix. There is a clear structure–activity relationship between cis-cis-p-menthenolide and anti-QS activity. Indeed, its isomer molecule (mintlactone) exerts a poor anti-QS action. These results indicate that inhibition of violacein production and biofilm formation by cis-cis-p-menthenolide might be related to a disruption in the QS mechanism.