Coumarins from Phebalium aff. brachycalyx

The genus Phebalium Vent. (Rutaceae, tribe Boronieae) includes some 45 species of shrubs and undershrubs, distributed in the southwest and southeast regions of Australia and in the northern island of New Zealand ( [Bentham and Mueller, 1863] and [Engler, 1896]). A consistent feature of all investigated species is the presence of coumarins ( [Quader et al., 1992] and [Ghisalberti, 1997]). In a major taxonomic revision, the genus was divided into four sections, Phebalium, Eristemoides, Gonioclados, and Leionema (Wilson, 1970). The species Phebalium brachycalyx P. G. Wilson is included in the section Phebalium, which comprises 19 species characterized by stem, leaves, and outside petals lepidote, and by an inflorescence in terminal umbel. Several taxa of this section previously led to the isolation of 7-geranyloxycoumarins, 8-prenylated coumarins, and linear furocoumarins ( [Rashid et al., 1992] and [Quader et al., 1992]). It was recognised (Wilson, 1970) that a number of the West Australian species of Phebalium sect. Phebalium hybridised and intergraded into one another and in that context P. brachycalyx underwent introgressive hybridisation with both P. filifolium and P. tuberculosum. More recently, Wilson (1998) has indicated that it may not be possible to maintain those taxa separated within this group. Accordingly, we refer to the collection here as P. aff. brachycalyx as it exhibits many of the characteristics ascribed to that taxon but clearly falls within the boundaries of the “super-species”. In a continuation of our studies on Australian Rutaceous plants (Girard et al., 2002), we report here the isolation and structure determination of two new heraclenol derivatives from P. aff. brachycalyx leaves and twigs, together with the identification of 22 other coumarins

Flow cytometric assessment of the antimicrobial properties of an essential oil mixture against Escherichia coli

International audienceEssential oils are increasingly being used in human health and animal farming as alternatives to antibiotics. The aim of this study was to better understand the mode of antimicrobial action of a natural essential oil mix (EO mix) by comparison with the colistin, as an antibiotic. The growth inhibitory concentration (GIC) of the EO mix and colistin was determined by turbidimetry. Escherichia coli exposed to EO mix and colistin were analysed by flow cytometry using the fluorescent dyes 3,3-diethyloxacarbocyanine iodide(DiOC(2)(3)) to assess membrane potential, and propidium iodide (PI) and SYTO9 to assess membrane integrity following treatment at the GIC and 1/2-GIC of the EO mix every h for 4 h. At 1 h, treatment with EO mix and colistin resulted in significant cell membrane alteration and depolarization. Membrane integrity measurements identified four sub-populations that were not distributed in the same way between EO mix and antibiotic treated cells. Colistin at GIC and 1/2-GIC drastically disintegrated the cells that appeared as debris (69.8% of cells were lysed after 1 h of treatment) whereas the EO mix at GIC altered membrane of a majority of cells (67.4 +/- 1.3% of cells were partially altered). Contact with 1/2-GIC EO mix led to sub-populations that persisted or recovered a physiological state with intact membrane (from 1 h to 4 h of treatment, intact cells increased from 23 to 33%). So, it was demonstrated that the EO mix presented antibacterial action against E. coli. It altered membrane properties by decreasing its polarity and integrity which were reversible phenomena here

Coumarins and furoquinoline alkaloids from Philotheca deserti var. deserti (Rutaceae)

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L’ensemble monétaire « aquitain sud-occidental » au second âge du Fer : une première approche

International audienceThe coinage attributed to Tarusates, people in the southwest of Gaul, is known since the 19th century thanks to hoards of Eyres-Moncube (1844) and Pomarez (1892). The datas collected so far don’t permit to define clearly this coinage. These silver coins, whose the circulation area was reduced to Adour’s basin and tributaries, are anepigraphs and present, in obverse and reverse, “protuberances”. Recents informations challenge not only the unicity of this coinage, but also the attribution of coins, revealing Gave de Pau’s area like privileged zone of diffusion and probably of fabrication. In fact, that’s a new monetary set: peoples’s from the southwest of Aquitania.Le monnayage attribué aux Tarusates, peuple du sud-ouest de la Gaule, est connu depuis le XIXe s. grâce aux trésors landais d’Eyres-Moncube (1844) et de Pomarez (1892). Les données recueillies jusqu’à aujourd’hui n’ont pas permis de faire toute la lumière sur ce monnayage et sur le ou les peuple(s) émetteur(s). Ces frappes en argent, dont l’aire de diffusion se trouvait jusqu’alors essentiellement réduite au bassin de l’Adour et à ses affluents, sont anépigraphes, et présentent, tant à l’avers qu’au revers, des « protubérances ». Des informations récentes remettent en cause non seulement l’unicité dudit monnayage, mais également l’attribution de ces monnaies, révélant la zone du Gave de Pau (Pyrénées-Atlantiques) comme aire privilégiée de diffusion, et probablement de fabrication. C’est en fait un nouvel ensemble monétaire qui se révèle peu à peu : celui des peuples du sud-ouest de l’Aquitaine

L’ensemble monétaire « aquitain sud-occidental » au second âge du Fer : une première approche

International audienceThe coinage attributed to Tarusates, people in the southwest of Gaul, is known since the 19th century thanks to hoards of Eyres-Moncube (1844) and Pomarez (1892). The datas collected so far don’t permit to define clearly this coinage. These silver coins, whose the circulation area was reduced to Adour’s basin and tributaries, are anepigraphs and present, in obverse and reverse, “protuberances”. Recents informations challenge not only the unicity of this coinage, but also the attribution of coins, revealing Gave de Pau’s area like privileged zone of diffusion and probably of fabrication. In fact, that’s a new monetary set: peoples’s from the southwest of Aquitania.Le monnayage attribué aux Tarusates, peuple du sud-ouest de la Gaule, est connu depuis le XIXe s. grâce aux trésors landais d’Eyres-Moncube (1844) et de Pomarez (1892). Les données recueillies jusqu’à aujourd’hui n’ont pas permis de faire toute la lumière sur ce monnayage et sur le ou les peuple(s) émetteur(s). Ces frappes en argent, dont l’aire de diffusion se trouvait jusqu’alors essentiellement réduite au bassin de l’Adour et à ses affluents, sont anépigraphes, et présentent, tant à l’avers qu’au revers, des « protubérances ». Des informations récentes remettent en cause non seulement l’unicité dudit monnayage, mais également l’attribution de ces monnaies, révélant la zone du Gave de Pau (Pyrénées-Atlantiques) comme aire privilégiée de diffusion, et probablement de fabrication. C’est en fait un nouvel ensemble monétaire qui se révèle peu à peu : celui des peuples du sud-ouest de l’Aquitaine

The scientific assessment on nitrogen flows in livestock farming: motives and methods

International audienceNitrogen is an essential nutrient in agriculture. Its reactive forms are the focus of concerns because they are responsible for a multitude of impacts on the environment and health. This was highlighted by the 2011 European Nitrogen Assessment, which drew up a critical inquiry on nitrogen imbalances due to livestock farming systems. The ambivalent status of nitrogen, both a resource for agriculture and a pollutant for environment, requires legal systems to find the equilibrium between the fertilising potential of the animal wastes and its possible negative effects on the environment. The European policies on nitrate and gaseous pollutants are the subject of much litigation with the European Commission. In this context, the French government asked for a synthesis of scientific knowledge on flows and fate of nitrogen related to livestock farms. Articles following in this review draw (i) the current situation, (ii) explain social and economic causes of the territorial variability of nitrogen pressure, (iii) quantify the flow on farms, (iv) look at indicators, (v) regulation instruments and finally (vi) identify options for reducing nitrogen pressure caused by livestock farming. In terms of materials and methods, a particular importance was given to peer recognition, and plurality inside the panel of experts and in the literature selectio

Taxonomically significant coumarins from three Philotheca species (Rutaceae)

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Coumarins from the twigs of Diplolaena mollis P. G. Wilson (Rutaceae)

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