Ecotoxicity Study of Amino Acid Ionic Liquids Towards Danio Rerio Fish: Effect of Cations

AbstractSix Ionic Liquids (ILs) were prepared based on phosphonium, ammonium and choline cations, with two types of amino acids specifically taurine and phenylalanine as anions. Good yields were obtained in the synthesis of the ILs. The toxicity of the synthesized ILs was checked against the Danio rerio fish (OECD 203). All six tested Amino Acid Ionic Liquids (AAILs) shows remarkably low toxicity towards Danio rerio fish

Solubility of acyclovir in nontoxic and biodegradable ionic liquids: COSMO-RS prediction and experimental verification

The pharmaceutical industry faces a challenge to find potential solvents for drug molecules that are sparingly soluble in water and organic solvents. Recently, ionic liquids (ILs) have attracted great attention as pharmaceutical solvents owing to their unique physicochemical and biological properties. In this study, the solubility of the sparingly soluble drug molecule acyclovir (ACV) in a wide variety of ILs was investigated by conductor-like screening model for real solvents (COSMO-RS) calculations. The predicted solubilities were validated by experimental measurements, and good agreement was found between the predicted and experimental results. The solubility of ACV was greatly affected by the structure of the ILs, particularly the anionic moiety. Among the various ILs tested, ACV showed excellent solubility in ammonium-based ILs with an acetate anion. In vitro cytotoxicity of ILs to the MCF-10 normal breast epithelial cell line and cancer cell lines (MDA MB 231 and MCF 7) was investigated. The ammonium-based ILs showed higher IC50 values than the imidazolium-based ILs with the acetate anion. Biodegradability results showed that diethylammonium acetate, triethylammonium acetate, and choline acetate ILs have high levels of biodegradation under aerobic conditions and can be classified as readily biodegradable. These findings will be useful for the design of IL-based drug delivery carriers that can act as versatile and efficient drug delivery systems for sparingly soluble drug molecules

Facilitative recovery of cyclodextrin glucanotransferase using chromatographic strategies

Cyclodextrin glucanotransferase (CGTase), are monomeric enzymes that are secreted extracellularly which catalyzes transglycosylation reactions via its glucosyl residues and are used as an acceptor in forming cyclodextrins (CD). CD’s, are widely used in the pharmaceutical, medicine, food, textile, agriculture and the cosmetic industries. Purifying CGTase is often a complicated task due to its heterogeneity, complexity and instability. To harness, it requires a set of downstream processing which typically consist of a cascade of recovery steps. The CGTase used in this study originated from Bacillus sp G1, which was successfully cloned and expressed in E.coli BL21. Recombinant CGTase was found to be growth related with maximum enzyme production at 167 U/mL after 10 hours of culture at 37⁰C in an orbital shaker with constant speed of 175 rpm. A series of pre purification strategies were carried out to determine the best method to concentrate the enzyme for subsequent purification procedures. Ammonium sulphate precipitation (70% saturation point) and dialysis tubing (SnakeSkin and flat tubing-with MWCO 3.5k) were investigated for concentrating the CGTase from E.coli culture. Results showed dialysis using SnakeSkin method to be superior to ammonium sulphate precipitation with CGTase yield of 148 U/mL and 19 U/mL respectively. Adsorbents used were mixed mode (of hydrophobic and ion exchange) ion exchangers, and immobilised metal affinity chelating. These adsorbents packed in a Tricorn 10/50 column, were screened for their suitability to purify CGTase by buffer optimization, frontal analysis and static binding evaluations. Purification yields using mixed mode chromatography were observed by using the mixed mode resin, PPA HyperCel which obtained 97% of CGTase enzyme recovery. Recovery performance were compared with other chromatography methods which is the ion exchange chromatography at 78% recovery and immobilised metal affinity chromatography at 87% recovery

Choline-based ionic liquids as media for the growth of Saccharomyces cerevisiae

Ionic liquids (ILs) have garnered great attention as alternative solvents in many biological reactions and applications. However, its unknown toxicity is in line with the challenges to use it for biological applications. In this study, three choline based Ionic Liquids—choline saccharinate (CS), choline dihydrogen phosphate (CDHP), and choline tryptophanate (CT) were assessed for their suitability on the growth of Saccharomyces cerevisiae. The ILs were incorporated into the growth media of S. cerevisiae (defined as synthetic media) to access its potential as a substitute to conventional media. The compatibility of the synthetic media was evaluated based on the toxicity (EC50), growth curve, and glucose profile. The results showed that the incorporation of CDHP and CS did promote the growth of S. cerevisiae with a rapid glucose consumption rate. The growth of S. cerevisiae with the media composition of yeast extract, peptone, and CS showed improvement of 13%. We believe that these observations have implications in the biocompatibility studies of ILs to microorganisms