Feasibility of Using 2,3,3,3-Tetrafluoropropene (R1234yf) as a Solvent for Solid–Liquid Extraction of Biopharmaceuticals

Tetrafluoropropene (R1234yf) is the most likely replacement for tetrafluoroethane (R134a), a widely used refrigerant, propellant and solvent, characterised by very high global warming potential. In this study solvation properties of R1234yf were studied experimentally and computationally for solubility of artemisinin, a precursor to the important bio-pharmaceutical API, and extraction of artemisinin from biomass. R1234yf was shown to be a poorer solvent than R134a for artemisinin. COSMO-RS calculations of solvation in R1234yf suggest that the decrease in performance is likely to be due to entropic effects. However, R1234yf was effectively used in solid liquid extraction of Artemisia annua. The new solvent has shown an increased selectivity to the target metabolite artemisinin. This should allow for design of more selective separation processes based on the new solvent molecule with a low global warming potential of 4 relative to CO2.This work was funded under iCON feasibility projects scheme of EPSRC “Centre for Continuous Manufacturing (CMAC)”, EP/IO33459/1. We acknowledge past funding from Medicine for Malaria Ventures for HPLC instrument and funding by University of Cambridge for the LCMS system

Feasibility of Using 2,3,3,3-Tetrafluoropropene (R1234yf) as a Solvent for Solid–Liquid Extraction of Biopharmaceuticals

Tetrafluoropropene (R1234yf) is the most likely replacement for tetrafluoroethane (R134a), a widely used refrigerant, propellant, and solvent, characterized by a very high global warming potential. In this study, solvation properties of R1234yf were studied experimentally and computationally for solubility of artemisinin, a precursor to the important biopharmaceutical API, and extraction of artemisinin from biomass. R1234yf was shown to be a poorer solvent than R134a for artemisinin. COSMO-RS calculations of solvation in R1234yf suggest that the decrease in performance is likely due to entropic effects. However, R1234yf was effectively used in solid–liquid extraction of Artemisia annua. The new solvent has shown an increased selectivity to the target metabolite artemisinin. This should allow for design of more selective separation processes based on the new solvent molecule with a low global warming potential of 4 relative to CO2.This work was funded under iCON feasibility projects scheme of EPSRC “Centre for Continuous Manufacturing (CMAC)”, EP/IO33459/1. We acknowledge past funding from Medicine for Malaria Ventures for HPLC instrument and funding by University of Cambridge for the LCMS system

Anti-plasmodial polyvalent interactions in Artemisia annua L. aqueous extract – possible synergistic and resistance mechanisms

Artemisia annua hot water infusion (tea) has been used in in vitro experiments against P. falciparum malaria parasites to test potency relative to equivalent pure artemisinin. High performance liquid chromatography (HPLC) and mass spectrometric analyses were employed to determine the metabolite profile of tea including the concentrations of artemisinin (47.5±0.8 mg L-1), dihydroartemisinic acid (70.0±0.3 mg L-1), arteannuin B (1.3±0.0 mg L-1), isovitexin (105.0±7.2 mg L-1) and a range of polyphenolic acids. The tea extract, purified compounds from the extract, and the combination of artemisinin with the purified compounds were tested against chloroquine sensitive and chloroquine resistant strains of P. falciparum using the DNA-intercalative SYBR Green I assay. The results of these in vitro tests and of isobologram analyses of combination effects showed mild to strong antagonistic interactions between artemisinin and the compounds (9-epi-artemisinin and artemisitene) extracted from A. annua with significant (IC50 <1 μM) anti-plasmodial activities for the combination range evaluated. Mono-caffeoylquinic acids, tri-caffeoylquinic acid, artemisinic acid and arteannuin B showed additive interaction while rosmarinic acid showed synergistic interaction with artemisinin in the chloroquine sensitive strain at a combination ratio of 1:3 (artemisinin to purified compound). In the chloroquine resistant parasite, using the same ratio, these compounds strongly antagonised artemisinin anti-plasmodial activity with the exception of arteannuin B, which was synergistic. This result would suggest a mechanism targeting parasite resistance defenses for arteannuin B’s potentiation of artemisinin

Social acceptance of renewable energy: Some examples from Europe and Developing Africa

Current energy systems are in most instances not fully working sustainably. The provision and use of energy only consider limited resources, risk potential or financial constraints on a limited scale. Furthermore, the knowledge and benefits are only available for a minor group of the population or are outright neglected. The availability of different resources for energy purposes determines economic development, as well as the status of the society and the environment. The access to energy grids has an impact on socio-economic living standards of communities. This not fully developed system is causing climate change with all its related outcomes. This investigation takes into consideration different views on renewable energy systems — such as international discussions about biomass use for energy production, “fuel versus food”, biogas use — and attempts to compare major prospects of social acceptance of renewable energy in Europe and Africa. Can all obstacles to the use of renewable energy be so profound that the overall strategy of reducing anthropogenic causes of climate change be seriously affected

Renewable, ethical? Assessing the energy justice potential of renewable electricity

Energy justice is increasingly being used as a framework to conceptualize the impacts of energy decision making in more holistic ways and to consider the social implications in terms of existing ethical values. Similarly, renewable energy technologies are increasingly being promoted for their environmental and social benefits. However, little work has been done to systematically examine the extent to which, in what ways and in what contexts, renewable energy technologies can contribute to achieving energy justice. This paper assesses the potential of renewable electricity technologies to address energy justice in various global contexts via a systematic review of existing studies analyzed in terms of the principles and dimensions of energy justice. Based on publications including peer reviewed academic literature, books, and in some cases reports by government or international organizations, we assess renewable electricity technologies in both grid integrated and off-grid use contexts. We conduct our investigation through the rubric of the affirmative and prohibitive principles of energy justice and in terms of its temporal, geographic, socio-political, economic, and technological dimensions. Renewable electricity technology development has and continue to have different impacts in different social contexts, and by considering the different impacts explicitly across global contexts, including differences between rural and urban contexts, this paper contributes to identifying and understanding how, in what ways, and in what particular conditions and circumstances renewable electricity technologies may correspond with or work to promote energy justice