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Vitex negundo L is a medicinal plant with many notable therapeutic effects. While the beneficial effects of Vitex negundo have been widely described, evidence of this herb's safety, such as acute and sub-chronic toxicity effects, remains scarce. This study aimed to evaluate the safety of this herb through acute and sub-chronic toxicity evaluation of aqueous ethanol extracts of its leaves in experimental animals. The acute toxicity study of aqueous ethanol leaf extract of Vitex negundo was performed in mature Swiss mice. The sub-chronic toxicity study was conducted in rabbits following the World Health Organization's guidance on evaluating the safety and efficacy of herbal medicines. In the acute toxicity study, the Vitex negundo leaf extract at 620.25 g/kg/day - the highest tolerable dose in mice, yielded no oral toxicity. In the sub-chronic toxicity study, Vitex negundo was administered orally to 2 groups of rabbits at doses of 3.2 g/kg/day and 9.6 g/kg/day, respectively, for eight weeks. The results showed no sign of general toxicity. There were no changes in growth or hematological parameters, liver and kidney functions, and no effect in the macromorphology and micromorphology of the treated animals' livers and kidneys. [ABSTRACT FROM AUTHOR]

Wood- (bamboo and melaleuca) and herbaceous-based (rice husk and water hyacinth) biochars, produced from local biomass by slow pyrolysis at 500 °C, 700 °C, and 900 °C, were examined for their physical and chemical properties. The wood-based biomass produced biochars with lower ash contents (<14 wt.%db ash) and higher fixed carbon contents (> 54 wt.%db), greater higher heating value (>23 MJ/kg), higher degree of aromaticity (with O/C, H/C, and volatile matter/fixed carbon ratios were less than 0.08, 0.51, and 0.61, respectively), and smaller amount of salt nutrients (<76 g/kgdb) compared with those of the herbaceous-based biochars. Their unique properties have generated more interest in using them as a solid fuel, for carbon sequestration, and for soil amendment. The rice husk biochars contained more than 300 g/kgdb silica, which is potential for silicophilic plants. The water hyacinth biochars with the greatest volatile matter/fixed carbon (ranging from 0.72 to 2.35), and highest O/C ratios (0.11 to 0.18), indicating the lowest aromaticity among studied biochars and thus maybe least suitability for carbon sequestration. They also possessed a highest soluble salts content (>240 g/kgdb), highest electrical conductivity (>6489 μS/cm), and greatest liming potential (>6.56 %CaCO3-eq), which may not be suitable for salt-sensitive plants or lowbuffer capacity soils. [ABSTRACT FROM AUTHOR]

The hydrodeoxygenation (HDO) of meta-cresol, a typical phenolic compound in bio-oils, is investigated in the vapor-phase on γ-Al2O3-supported Pt catalysts at near atmospheric hydrogen pressure. The HDO reaction yields two major hydrocarbons: toluene and methylcyclohexane. The deoxygenation of meta-cresol proceeds through two consecutive steps: hydrogenation of the aromatic ring on the Pt metal followed by dehydration reactions of the produced alcohol intermediates on the alumina support. Phenolic ring saturation is proposed to be slower than its sequential dehydration steps on Pt/γ-Al2O3. This is in a good agreement with the higher selectivity of toluene compared to that of the hydrogenated cyclic hydrocarbon, methylcyclohexane, because toluene formation requires fewer ring hydrogenation steps than its counterpart. The additions of Co and Ni into Pt not only improve the overall HDO conversion, but also modify the product distribution. The enhancement in the overall HDO activity is related to the better hydrogenation activity of bimetallic Pt–Co and Pt–Ni catalysts and the generation of additional sites for alcohol dehydration. Consequently, more saturated cyclic hydrocarbon product, methylcyclohexane, is observed on bimetallic catalysts with respect to the monometallic Pt catalyst. [ABSTRACT FROM AUTHOR]

The deoxygenation of methyl octanoate and methyl stearate over alumina-supported Pt was studied in both the vapor phase in a flow reactor and in the liquid phase in a semibatch reactor. The conversion of both methyl esters resulted in hydrocarbons with one carbon less than the fatty acid of the corresponding ester as the dominant products. In the vapor phase, acid and other oxygenates were observed in low concentrations, but they were not detected when the reaction was conducted in the liquid phase. Under He, condensation products (from esterification and ketonization) were observed. By contrast, under H2, mostly paraffins were obtained. These results show promise to directly produce standard diesel components from biodiesel. [ABSTRACT FROM AUTHOR]

The deoxygenation of methyl octanoate and methyl stearate over alumina-supported Pt was studied in both the vapor phase in a flow reactor and in the liquid phase in a semibatch reactor. The conversion of both methyl esters resulted in hydrocarbons with one carbon less than the fatty acid of the corresponding ester as the dominant products. In the vapor phase, acid and other oxygenates were observed in low concentrations, but they were not detected when the reaction was conducted in the liquid phase. Under He, condensation products (from esterification and ketonization) were observed. By contrast, under H2, mostly paraffins were obtained. These results show promise to directly produce standard diesel components from biodiesel. [ABSTRACT FROM AUTHOR]

The reaction of 2,5-dimethylfuran and ethylene to produce p-xylene represents a potentially important route for the conversion of biomass to high-value organic chemicals. Current preparation methods suffer from low selectivity and produce a number of byproducts. Using modern separation and analytical techniques, the structure of many of the byproducts produced in this reaction when HY zeolite is employed as a catalyst has been identified. From these data, a detailed reaction network is proposed demonstrating that hydrolysis and electrophilic alkylation reactions compete with the desired Diels-Alder/dehydration sequence. This information will allow the rational identification of more selective catalysts and more selective reaction conditions.