32132-71-1Relevant articles and documents
Synthesis of a series of amino acid derived ionic liquids and tertiary amines: Green chemistry metrics including microbial toxicity and preliminary biodegradation data analysis
Jordan, Andrew,Hai?, Annette,Spulak, Marcel,Karpichev, Yevgen,Kümmerer, Klaus,Gathergood, Nicholas
, p. 4374 - 4392 (2016)
A series of l-phenylalanine ionic liquids (ILs), l-tyrosine ILs, tertiary amino analogues and proposed transformation products (PTPs) have been synthesised. Antimicrobial toxicity data, as part of the green chemistry metrics evaluation and to supplement preliminary biodegradation studies, was determined for ILs, tertiary amino analogues and PTPs. Good to very good overall yields (76 to 87%) for the synthesis of 6 ILs from l-phenylalanine were achieved. A C2-symmetric IL was prepared from TMS-imidazole in a one-pot two-step method in excellent yield (91%). Synthesis of the l-tyrosine IL derivatives utilised a simple protection group strategy by using an extra equivalent of the bromoacetyl bromide reagent. Improvements in the synthesis of the α-bromoamide alkylating reagent from l-phenylalanine were achieved, directed by green chemistry metric analysis. A solvent switch from dichloromethane to THF is described, however the yield was 15% lower. Antimicrobial activity testing of l-phenylalanine ILs, l-tyrosine ILs, tertiary amino analogues and PTPs, against 8 bacteria and 12 fungi strains, showed that no compound had a high antimicrobial activity, apart from an l-proline analogue. In this exceptional case, the highest toxicity (IC95 = 125 and 250 μM) was observed towards the two Gram positive strains Staphylococcus aureus and Staphylococcus epidermidis respectively. High antimicrobial activity was not found for the other bacteria or fungi strains screened. The limitations of the antimicrobial activity study is discussed in relation to SAR studies. Preliminary analysis of biodegradation data (Closed Bottle Test, OECD 301D) is presented. The pyridinium IL derivative is the preferred green IL of the series based on synthesis, toxicity and biodegradation considerations. This work is a joint study with Kümmerer and co-workers and the PTPs were selected as target compounds based on concurrent biodegradation studies by the Kümmerer group. For the comprehensive biodegradation and transformation product analysis see the accompanying paper.
Antimicrobial toxicity studies of ionic liquids leading to a 'hit' MRSA selective antibacterial imidazolium salt
Coleman, Deborah,Spulak, Marcel,Garcia, M. Teresa,Gathergood, Nicholas
supporting information; experimental part, p. 1350 - 1356 (2012/06/16)
Imidazolium salts can be classed as surfactants, detergents, ionic liquids, reagents, catalysts or solvents. A study of the toxicity and ecotoxicity of these salts yields valuable information for their use as pharmaceuticals as well as impact on the environment. Our approach to screen a series of chiral imidazolium salts for toxicity to bacteria and fungi, including clinical pathogen strains, has led to the identification of a 'hit' MRSA selective antimicrobial compound. Preliminary structure-activity-relationship (SAR) information (required position of l-phenylalanine and l-valine group) is also elucidated within this first generation of compounds. Conversely, most of the imidazolium salts were nontoxic (IC95 > 2 mM) to the 12 fungi strains and 8 bacteria strains screened, and we propose that they are suitable candidates for 'green chemistry' applications. Ecotoxicity studies (Biodegradation ISO 14593 'CO2 Headspace Test') of two bromide ionic liquids containing l-phenylalanine residues indicate that these ionic liquids passed the test (>60% in 28 days) and classed as readily biodegradable.
Structure-activity relationships in tetramic acids and their copper (II) complexes
Matsuo,Kitaguchi,Takata,Tanaka
, p. 2494 - 2502 (2007/10/02)
-
