Integrated Green Chemical Approach to the Medicinal Plant Carpobrotus edulis Processing

Associate Laboratory for Green Chemistry (LAQV), which is financed by national funds from FCT/MCTES (UID/QUI/50006/2019).Many plants have medicinal properties due to substances known as phytochemicals. To utilize these plants in practice, numerous procedures, such as extraction, isolation and characterization methods and toxicology and bioactivity studies, must be designed and implemented. Integrated approach to process Carpobrotus edulis, a weed medicinal plant widely spread in Portugal, was developed into a closed loop of two processes: microwave assisted extraction (MAE) and activation (MAA), to produce both phytochemicals and biochar. The use of MAE for phytochemical extraction was shown to be more energy efficient than conventional Soxhlet extraction: the process time was decreased by 7–8 times, and the energy efficiency was increased by up to 97%. The yield of the extracts is of 27%. Qualitative and quantitative identification/characterization of the phytochemicals were performed by LC-MS and phytochemical screening assays. The results clearly indicated that Carpobrotus edulis is rich by flavonoids (up to 24%). The use of MAA to process the residual biomass could shorten the activation time, resulting in reduced energy consumption. Biochar with a high yield of 65% (on a biomass basis) and a well-developed texture (surface area of 68.9 m2/g; total pore volume of 0.10 cm3/g; micropore volume of 0.07 cm3/g) is obtained.publishersversionpublishe

International circular economy strategies and their impacts on agricultural water use

Publisher Copyright: © 2022 The AuthorsThe concept of Circular Economy (CE) is becoming increasingly important in the pursuit of more sustainable societies. CE strategies are being applied in the sustainable management of a plethora of areas, such as energy, water, food and eco-industrial parks. The present paper focuses on the question of how CE principles can support the sustainable management of water in the agricultural sector around the world, considering different legislative environments, water resources management guidelines, environmental stressors, and CE practices. Considering these practices and circumstances, seven countries were compared: Brazil, Germany, Japan, Mexico, Morocco, Portugal, and Taiwan. Together, CE experts in the seven countries developed a set of 44 criteria to assess each of these areas. Broader establishment and respect of water resources legislation was found to be strongly correlated with lower agricultural water use. While the application of CE practices was found to not be correlated with lower consumption, this is still novel in most countries. Based on the studied countries, it can be concluded that a global CE agenda has not been reached for water resources. Further application and variety of practices is required to better represent the impact of CE on a national scale, but local success stories could support the wider application of CE in agriculture. The findings and the framework of the study can be applied to other countries in directing CE strategies for more sustainable water use in agriculture. Increasing CE implementation, motivated by legislation and better management can help ensure water security throughout nations.publishersversionpublishe

Copper complexes with a flexible piperazinyl arm: nuclearity driven catecholase activity and interactions with biomolecules

<p>Three new Cu(II) complexes, [Cu(HL¹)(pyridine)(H₂O)](ClO₄)₂·2MeOH (<b>1</b>), [Cu₂(HL¹)₂(NO₃)₂](NO₃)₂·3H₂O (<b>2</b>) and [Cu(HL₂)(NO₃)₂]·MeCN (<b>3</b>), have been synthesized from two Schiff base ligands [HL¹ = 1-phenyl-3-((2-(piperazin-4-yl)ethyl)imino)but-1-en-1-ol and HL² = 4-((2-(piperazin-1-yl)ethyl)imino)pent-2-en-2-ol] using the chair conformer of a flexible piperazinyl moiety. Structural analysis reveals that <b>1</b> and <b>3</b> are monomeric Cu(II) complexes consisting of five- and six-coordinate Cu(II), respectively, whereas <b>2</b> is a dinuclear Cu(II) complex consisting of two different Cu(II) centers, one square planar with the other distorted octahedral. Screening tests were conducted to quantify the binding of <b>1</b>–<b>3</b> towards DNA and BSA as well as the DNA cleavage activity of these complexes using gel electrophoresis. Enzyme kinetic studies were also performed for the complexes mimicking catecholase-like activities. Antibacterial activities of these complexes were also examined towards Methicillin-Resistant <i>Staphylococcus aureus</i> bacteria. The results reflect that <b>2</b> is more active than the monomeric complexes, which is further corroborated by density functional theory study.</p