Maria Paula Duarte

Catechols from abietic acid synthesis and evaluation as bioactive compounds.

Catechols from abietic acid were prepared by a short and good yielding chemical process and further evaluated for several biological activities namely, antifungal, antitumoral, antimutagenic, antiviral, antiproliferative and inhibition of nitric oxide. Their properties were compared with those of carnosic acid (6), a naturally occurring catechol with an abietane skeleton and known to possess potent antioxidant activity, as well as anticancer and antiviral properties. From all the synthetic catechols tested compound 2 showed the best activities, stronger than carnosic acid.

IMPAIRMENT OF HUMAN CYP1A2-MEDIATED XENOBIOTIC METABOLISM BY ANTLEY-BIXLER SYNDROME VARIANTS OF CYTOCHROME P450 OXIDOREDUCTASE

Y459H and V492E mutations of cytochrome P450 reductase (CYPOR) cause Antley-Bixler syndrome due to diminished binding of the FAD cofactor. To address whether these mutations impaired the interaction with drug-metabolizing CYPs, a bacterial model of human liver expression of CYP1A2 and CYPOR was implemented. Four models were generated: POR(null), POR(wt), POR(YH), and POR(VE), for which equivalent CYP1A2 and CYPOR levels were confirmed, except for POR(null), not containing any CYPOR. The mutant CYPORs were unable to catalyze cytochrome c and MTT reduction, and were unable to support EROD and MROD activities. Activity was restored by the addition of FAD, with V492E having a higher apparent FAD affinity than Y459H. The CYP1A2-activated procarcinogens, 2-aminoanthracene, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, and 2-amino-3-methylimidazo(4,5-f)quinoline, were significantly less mutagenic in POR(YH) and POR(VE) models than in POR(wt), indicating that CYP1A2, and likely other drug-metabolizing CYPs, are impaired by ABS-related POR mutations as observed in the steroidogenic CYPs.

Genotoxicity of instant coffee: possible involvement of phenolic compounds.

Instant coffee exhibits direct genotoxic activity in the tester strains TA 98, 100, 102, 104 and YG 1024. In the Ames tester strain TA 100, the presence of S9 mix, S100 mix, S9 mix without cofactors led to a significant decrease of the genotoxicity observed. The decrease observed in the presence of S9 mix seems to be highly correlated with the catalase content of S9 mix. The genotoxicity of instant coffee detected in strain TA 100 was dependent on the pH, with higher genotoxic effects at pH values above neutrality. Also, dependent on the pH was the ability of some phenolic molecules present in coffee promoting the degradation of deoxyribose in the presence of Fe3+/EDTA. These results suggest that apart from other molecules present in instant coffee responsible for their genotoxicity in several short term assays, phenolic molecules could also be implicated in the genotoxicity of coffee, via reactive oxygen species arising from its auto-oxidation.

Benchmarking the Environmental Performance of the Jatropha Biodiesel System through a Generic Life Cycle Assessment

In addition to available country or site-specific life cycle studies on Jatropha biodiesel we present a generic, location-independent life cycle assessment and provide a general but in-depth analysis of the environmental performance of Jatropha biodiesel for transportation. Additionally, we assess the influence of changes in byproduct use and production chain. In our assessments, we went beyond the impact on energy requirement and global warming by including impacts on ozone layer and terrestrial acidification and eutrophication. The basic Jatropha biodiesel system consumes eight times less nonrenewable energy than conventional diesel and reduces greenhouse gas emissions by 51%. This result coincides with the lower limit of the range of reduction percentages available in literature for this system and for other liquid biofuels. The impact on the ozone layer is also lower than that provoked by fossil diesel, although eutrophication and acidification increase eight times. This study investigates the general impact trends of the Jatropha system, although not considering land-use change. The results are useful as a benchmark against which other biodiesel systems can be evaluated, to calculate repayment times for land-use change induced carbon loss or as guideline with default values for assessing the environmental performance of specific variants of the system.

Perennial Grass Production Opportunities on Marginal Mediterranean Land

An increasing global awareness that the supply and security of petroleum-based materials is diminishing, coupled with environmental concerns related to climate change, water availability, and soil degradation, has increased demand for more renewable, diversified, and sustainable agricultural production systems. The objective of this work was to determine if a biogenic approach, focused on producing perennial grasses on marginal Mediterranean land as feedstock for bioenergy or bio-based products, could reduce greenhouse gas (GHG) emissions without depleting soil nutrients, water supplies, or negatively impacting biological and landscape diversity. This study, funded by European Union (EU), was conducted under project optimization of perennial grasses for biomass production (OPTIMA) using environmental impact assessment (EIA) protocols to quantify local environmental impacts of producing perennial grasses, in the Mediterranean region. Different end uses were investigated and biogenic products were compared with conventional ones. The EIA assessment indicated that the biogenic system had low erodibility potential, reduced disturbance of soil properties, and minimal hydrological impacts. Less tillage and high biomass production supported biological and landscape diversity, but site-specific factors should be used to appropriately match the specific crop and location. We conclude that producing perennial grasses on marginal Mediterranean land is feasible and if appropriately managed will have relatively few environmental side effects.

Genotoxicity of instant coffee and of some phenolic compounds present in coffee upon nitrosation.

Instant coffee exhibits genotoxic activity upon nitrosation at acidic pH values in the Ames tester strain TA100. Using adsorption chromatography (Amberlit XAD-2) it was observed that the major fraction of molecules responsible for the genotoxic activity upon nitrosation was not retained on this resin, suggesting that the polar molecules present in instant coffee could be responsible for the genotoxicity observed upon nitrosation. Some phenolic molecules present in instant coffee (catechol, caffeic acid, and chlorogenic acid) were also genotoxic upon nitrosation under the same experimental conditions. The concentrations of nitrosatable phenolic compounds in the studied coffee were determined by HPLC and their contributions to the total genotoxicity observed were studied. The results obtained suggest that besides phenolic compounds other molecules were also involved in the genotoxicity of this beverage upon nitrosation. Teratogenesis Carcinog. Mutagen. 20:241-249, 2000.

Phytoremediation of Inorganic Compounds

Phytoremediation, the use of plants and their associated microbes for soil, water, and air decontamination, is a cost-effective, solar-driven, and alternative/complementary technology for physicochemical approaches. Plants can be used for extraction, stabilization, degradation, and volatilization as well as for the conversion of many inorganic compounds as nitrates, phosphates, metals, and radionuclides to less toxic forms, reducing their associate risks to humans, animals, and the environment. The applicability of these mechanisms is reviewed here, including its applicability for soils contaminated with heavy metals and radionuclides, as well as the application of plants for the improvement of water quality in polluted waters (phytodepuration). Main polluted sites in Europe and main polluting anthropogenic activities where identified. The main soil remediation technologies, and, in particular, the application of phytoremediation technology using industrial crops and their mechanisms with the generation of economic value was referred. The advantages and limitations of this approach are also presented. Bridging phytoremediation with the production of a multipurpose biomass could provide environmental benefits and social and economic opportunities, by improving the overall sustainability of the biosystem.

Efficient coverage of ZnO nanoparticles on cotton fibres for antibacterial finishing using a rapid and low cost in situ synthesis

Zinc oxide nanoparticles (ZnONPs) have received considerable attention as an antibacterial agent particularly in the textile industry. In the present work a successful procedure for in situ growth of ZnONPs in textiles was developed. The results obtained showed that a combination of in situ synthesis and the sol–gel method promoted a uniform and dense adsorption of the nanoparticles both inside and on the surface of fabric fibres. The fabrics finished with ZnONPs have been investigated for antibacterial properties by the agar diffusion method and by the absorption method according to the ISO 20743:2013 standard and exhibited an antibacterial effect against methicillin resistant Staphylococcus aureus ATCC33591, Staphylococcus epidermidis ATCC1228, Staphylococcus aureus RN4220 and Propionibacterium acnes ATCC6919. Moreover, tests conducted with hydrogen peroxide suggested the involvement of reactive oxygen species, namely the involvement of hydrogen peroxide, in the antibacterial activity of the zinc oxide nanoparticles. Therefore, the synthesised nanoparticles showed great potential to be used as coatings for medical, cosmetic or sports fabrics.

Influence of the in vitro gastrointestinal digestion on the antioxidant activity of Artemisia gorgonum Webb and Hyptis pectinata (L.) Poit. infusions from Cape Verde

The phenolic profile and antioxidant activity of Cape Verdes Artemisia gorgonum Webb and Hyptis pectinata (L.) Poit. infusions before and after in vitro simulation of the gastrointestinal digestion were determined. The LC-UV/DAD fingerprinting analysis allowed the identification of 3-O-caffeoylquinic acid, chlorogenic acid, 3,5 dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid and other caffeoylquinic acids derivatives on A. gorgonum infusion, and of caffeoylquinic acid and quercetin derivatives on H. pectinata infusion. Despite some decrease in the chromatographic area of several peaks, no relevant qualitative alterations on the chromatographic profile were observed between the digested and undigested herbal infusions. Results obtained showed a decrease on the antioxidant capacity of both tested herbal infusions after the in vitro digestion. This decrease was more pronounced for H. pectinata than for A. gorgonum and was also more pronounced regarding the radical scavenging capacity than regarding the reducing capacity. After complete digestion the superoxide anion and the DPPH-radical scavenging capacities decreased ≈ 43 and 75% for H. pectinata and ≈ 31 and 70% for A. gorgonum. Despite the observed differences before and after simulated gastrointestinal digestion, both infusions still had antioxidant activity at the end of this process. Thus, the antioxidant potential of A. gorgonum and H. pectinata infusions from Cape Verde, prepared as traditionally used, seems to be kept in some extend throughout the digestive system.

CHARACTERIZATION OF SWEET, FIBRE AND BIOMASS SORGHUM POTENTIAL IN PORTUGAL AS AN INDUSTRIAL AND ENERGY FEEDSTOCK

The purpose of this work was to investigate the influence of crop management on the sorghum biomass quality and productivity, in Portugal, in order to access its potential as an industrial and energy feedstock. To do so, the effects of different fertilization levels, the sowing date and the harvest date in the biomass quality and productivity, were studied. Productivity was affected by the level of nitrogen and by the sowing date. Highest productivities were obtained in the most N-fertilised fields and in fields sowed between 251h March and 1’‘ May. Among subspecies, Sweet and Biomass Sorghum presented, globally, higher productivities than Fibre Sorghum. In all the experimental years, highest productivities, in all the fields, were achieved at 193 5 9 days after sowing, regardless of all the different sowing dates. Biomass quality was affected by the crop productivities. Fields with lowest productivities resulted in a biomass with a higher nitrogen and ash contents, namely the fields sowed at 2nd June and the fields without N-fertiliser. In the experimental conditions at Caparica, sweet sorghum crop showed a better potential as an industrial and energy feedstock, and to get better results, economically and environmentally, fields should he sowed between 25’h March and 1’‘ May, with a high nitrogen input (120 kg N/ha).