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The biomass of Eucalyptus globulus , and particularly the stump wood, has received increased attention in recent years, including in a biorefinery perspective. A previous work evaluated the crude methanolic extract of E. globulus stump wood regarding its potential antioxidant and antimicrobial properties. That work concluded that E. globulus stump wood could be considered as a source of bioactive polyphenols. In the present study, the crude methanolic extract of E. globulus stump wood was thus fractionated in order to isolate the components responsible for such biological properties. This extract was subjected to bioassay-guided fractionation and the antioxidant and antimicrobial properties of the fractions were then evaluated. The antioxidant activity was assessed by the DPPH scavenging assay and the antimicrobial properties were studied by bioautography and resazurin microtiter methods. The fractions presented considerable capacity to scavenge the DPPH free radicals and to inhibit the growth of bacterial and yeast strains. The results obtained for the fractions were even better than the ones obtained with the crude extract. The GC–MS analysis revealed that the major compounds present in the extract were gallic acid, ellagic acid, citramalic acid and citric acid. [ABSTRACT FROM AUTHOR]

The interest in plant polyphenol antioxidants has increased remarkably over the last decade mostly because of their protective effects against different diseases, including cardiovascular, inflammatory and neurological diseases, cancer as well as for retarding aging. Many naturally occurring polyphenols found in plants and spices have also been shown to possess antimicrobial properties and could serve as a source of antimicrobial agents. Eucalyptus globulus and Eucalyptus radiata are well known species that provide essential oils. These oils are in great demand in the market, since they find a vast array of applications. The present study was performed to evaluate some bioactivities of the essential oils from E. globulus and E. radiata , namely their antioxidant, antibacterial and anti-quorum sensing properties. Moreover, its chemical composition was assessed and the potential synergistic activity with conventional antibiotics against Acinetobacter baumannii strains was also evaluated. The major component of the E. globulus oil was 1,8-cineole, also known as eucalyptol (63.81%), and in the E. radiata oil, the principal component was limonene (68.51%). It was possible to conclude that both eucalypt essential oils presented relevant radical scavenging properties and also had the capacity to inhibit the lipid peroxidation. The E. globulus oil antioxidant properties stand out when compared to the E. radiata oil. The E. radiata oil had a more pronounced antibacterial activity than E. globulus oil. The studied eucalypt essential oils can act as potential improving agents of antibiotics against A. baumannii , considering the synergic effect obtained between these oils and conventional antibiotics. Both eucalypt essential oils now studied can inhibit the quorum sensing phenomena, inhibiting quorum sensing-regulated violacein pigment production in bacteria without interfering with their growth. [ABSTRACT FROM AUTHOR]

Abstract: Production of bioethanol from biomass is one way to reduce both consumption and depletion of fossil fuels and environmental pollution. The conversion of lignocellulosic biomass-to-ethanol comprehends three major steps: thermochemical pretreatment, enzymatic saccharification and fermentation. The aim of this work is to study the influence of dilute acid pretreatment conditions in sugars removal and in enzymatic saccharification of Erica spp. for bioethanol production as well as the influence of poly(ethylene)glycol addition to the enzymatic saccharification step. Pretreatment of Erica spp. with dilute sulfuric acid was studied at different conditions of reaction time, temperature and acid concentration. The influence of supplementation of enzymatic saccharification with poly(ethylene)glycol 4000 and concentration of polymer were tested, using as response the release of glucose and the adsorption of cellulase to biomass by protein content in supernatant and by SDS-PAGE. The addition of PEG 4000 affects the adsorption of cellulase and influences the yield of enzymatic saccharification, leading to an improvement of 13–74% depending on the pretreatment applied to biomass. A maximum of 440mg glucose/g dry biomass was obtained by enzymatic saccharification when pretreated Erica spp. at 180°C with 2.75% of sulfuric acid for 75min, supplemented with 0.25g/g dry biomass of PEG 4000, was used. The observation of biomass structure by scanning electron microscopy after pretreatment reveals visible breaks in the structure, which could be related to the improvement of enzymatic process. [Copyright &y& Elsevier]

Abstract: Total chlorine free (TCF) and elemental chlorine free (ECF) bleaching sequences were applied to an Arundo donax L. (giant reed) unbleached kraft-anthraquinone pulp, using different sequences with hydrogen peroxide and chlorine dioxide stages. The evolution of ISO brightness, kappa number and pulp viscosity was observed for each stage in all bleaching sequences, as well as the process selectivity. The best results were obtained with the XOQDP sequence with a final ISO brightness of 80%. The effect of a chelating stage before the hydrogen peroxide stage was studied, and the results showed higher pulp viscosity, less peroxide consumption and higher pulp brightness, when this treatment is applied. [Copyright &y& Elsevier]

Abstract: The ethanol and acetone/water extracts of Cistus ladanifer and Arbutus unedo L. were characterised concerning the total phenolic and flavonoid contents, presenting relatively high values when compared with other species described in the literature. The antioxidant activity was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method in terms of EC50, using trolox as standard reference. The extracts of both species showed scavenging activity for the DPPH radical. Extracts bioactivities were also tested by the evaluation of the viability effects on human fibroblasts primary culture cells. Viability studies were performed by MTT method. Both extracts are bioactive; C. ladanifer extracts were associated with an inhibitory effect and A. unedo L. were associated with an induced effect on cells viability. [Copyright &y& Elsevier]