Is it green? How can you tell?
How do you know if a solvent is green? ITQB researchers (Molecular Thermodynamics and Applied and Environmental Mycology Labs) and collaborators have devised a new method to assess the biocompatibility of ionic liquids through direct analyses of fungal membrane integrity by fluorescence microscopy. The method is described in the latest issue of the New Journal of Chemistry. The work is highlighted both on the journal cover and in the “meet the authors” section of the journal’s blog.
While ionic liquids are regarded as green solvents for being essentially unable to evaporate to the atmosphere, actually they comprise a wide range of different compounds that are not intrinsically green: some are toxic and non-biodegradable. Analysis of their greenness must therefore be made on an individual, specific basis. Researchers now propose to resort to fluorescence microscopy to check the impact of ionic liquids on fungal cell walls and membranes. In particular, researchers analyzed the effect of a particular class of ionic liquids (phosphonium ionic liquids) on fungal spores of Aspergillus nidulans and concluded that nonspecific disruption of the membranes, and not a process of programmed cell death, was the basis for their toxic action.
The biocompatibility of ionic liquids is not just a matter of curiosity. In fact, ionic liquids have already inspired numerous patents for a broad range of applications, such as intermediates in chemical synthesis, antistatic agents, biocides, either alone or combined with other compounds, plant growth regulators, and anti-cancer agents. According to the authors, the method now described is "also adequate for the study of bacteria and mammalian cells, constituting a robust screening method, which should stimulate ionic liquids research towards their conscious design".
Original Article
New J. Chem., 2012, 36, 56-63, DOI: 10.1039/C1NJ20470J.
Unravelling the mechanism of toxicity of alkyltributylphosphonium chlorides in Aspergillus nidulans conidia
Marija Petkovic, Diego O. Hartmann, Gabriela Adamová, Kenneth R. Seddon, Luís Paulo N. Rebelo and Cristina Silva Pereira
