Chemical composition, antibacterial and antioxidant activities of essential oils from flowers, leaves and aerial parts of Tunisian Dittrichia Viscosa

The objective of this work was to determine the chemical composition, the antioxidant and antibacterial activities of the essential oils (EOs) extracted by hydrodistillation from different organs of the D. viscosa: flowers, leaves and aerial parts. The main compounds identified by GC/MS are oxygenated sesquiterpenes. Among these compounds, (E)-nerolidol (40.7%) is the most abundant constituent of flowers’ essential oil while caryophyllene oxide (9.9%), isolongifolan-7-α-ol (10.3%) and α -eudesmol (9.1%) are the major constituents of the leaves’ essential oil. The presence of these compounds in the aerial parts’ essential oil is solely due to those of the flowers and leaves that constitute these aerial parts. The volatile extracts showed antioxidant effects with IC50 values ranging between 9.25 and 9.75 mg.mL−1. On the other hand, EOs showed antibacterial effects on both Gram-positive and Gram-negative bacteria. The highest activity was obtained with flowers’ essential oil against Enterococcus faecalis and Escherichia coli

Synthèse de résines échangeuses de cations fabriquées à partir de déchets plastiques

The objective of this work is to study the possible reuse of some plastic wastes mainly composed of polystyrene (yogourt packing and mug) as cationic exchangers. The resins, thus obtained, can be used as synthetic ion exchange resins (phenolic polymers as polystyrene).Polystyrene wastes were sulfonated to obtain a strong acid cationic exchanger with an exchange capacity (CEC) varying from 11,5 to 16,5 meq/l depending on the waste. These samples as well as a commercial resin, for which the CEC is equal to 27 meq/l, were use for water softning, and enabled us to reduce the water hardness from 11,6 meq/l to 2-3 meq/l. A striking feature was that the synthesized resins had a particular affinity towards divalent cations, as the commercial resins removed both divalent and monovalent cations. These results show the possible use of the sulofonated polystyrene wastes for an economic water softning. Indeed, it can be for a great industrial and domestic interest to reduce in an economic way the hardeness of the water feeding boilers or wash machine.Des résines échangeuses de cations ont été synthétisées à partir de déchets plastiques à base de polystyrène. Le but étant de pouvoir utiliser un matériau peu coûteux afin d’adoucir une eau de réseau très dure (60°F) en vue de son utilisation domestique (machine à laver) et industrielle (eaux de chaudière, eaux de refroidissement).Après sulfonation de ces matériaux plastiques des résines sous forme de gel ont été obtenues avec des capacités d’échange cationiques (CEC) allant de 11,5 à 16,5 méq/l selon la nature du déchet. Des tests d’adoucissement de l’eau de réseau par ces résines ainsi que, par comparaison, par une résine commerciale ont permis de réduire la dureté de 11,6 méq/l à 2-3 méq/l. Le résultat du dosage de la capacité utilisée a en outre permis de démontrer que ces résines présentaient une affinité particulière vis à vis des cations divalents responsables de la dureté alors que la résine commerciale retenait tous les cations présents sans distinction