## 2 Topical Research Areas Related to Ionic Liquids and the Contribution of Spiroammonium Compounds
### Green Chemistry and the IL Concepts
#### 2.2.4 Creation of the Low-Toxic Ionic Liquids and the Variants of Their Use
This strategy was applied to the peracetylated species of D-lyrose, D-xylose, and L-arabinose to synthesize nine new pyridinium salts and seven new pyridinium salts with different glucosides. In the latter case, the starting materials were \(\beta\)-D-methyl, allyl, and phenyl glucosides, as well as \(\alpha\)-D-methyl glucoside (Scheme 2). Thermal analysis showed that 13 of the 16 synthesized derivatives of these new carbohydrate-based pyridinium salts qualify as ionic liquids per the definition, with melting points below 100 \({}^{\circ}\)C, with most of them even being room-temperature ionic liquids. For screening tests on L929 biocompatibility, mouse fibroblasts were used. The results consisted of naturally occurring molecules or their derivatives. Biocompatibility tests proved that these ionic liquids are suitable for biomedical applications as they exhibited much higher viability than common imidazolium or phosphonium-based ILs, which were tested for comparison. Catalyst design is considered a key approach to the development of efficient, low-energy, and environmentally friendly processes. Enzymatic acrylation processes are an area where the superior properties of ILs have been demonstrated [92]. Multiwalled carbon nanotubes (MWCNTs) modified by D-glucose-based ionic liquids can be used to form one of the components of the catalytic enzyme complex for lipase B from a _Candida antarctica_ (CALB) biocatalyst. The screening of three imidazolium-based ionic liquids, 1-butyl-3-methylimidazolium octylsulphate [bmim][O\(\zeta\)SO\({}_{4}\)], 1-butyl-3-methylimidazolium dioctylphosphate [bmim][O\(\zeta\)EO\({}_{4}\)], 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [bmim][N(Tf)\({}_{2}\)], as well as IL based on D-glucose - N-(6-deoxy-1-O-methoxy-\(\alpha\)-D-glucopyranosyl)-N,N,N-trimethylammonium bis(trifluoromethylsulfonyl)imide ([N(CH\({}_{3}\))\({}_{3}\)GlcOCH\({}_{3}\)][N(Tf)\({}_{2}\)]), showed that the most promising result is obtained in the case of using a D-glucose-based IL (Figure 4a). Favorable reaction conditions enabled a 99% yield of n-butyl acrylate in 24 h. The developed biocatalytic system could operate for five cycles. The developed method opens a new path to more environmentally friendly, economical, and superior universal catalysts. A series of novel glucose-based ILs was synthesized in high yields in simple two- or three-step reaction procedures (Figure 4b) [93]. These carbohydrate-based ionic liquids were studied and compared with commercially available imidazolium-based ILs as supports for commercially available biocatalyst Novozym 435 in the acrylation of n-butanol. A direct correlation between the availability of hydroxy groups and the overall activity and enhanced recyclability (up to 10 cycles) of the biocatalyst was found for new glucose-based ILs. All IL-supported Novozym 435 biocatalysts led to similar or overall higher yields of \(n\)-butyl acrylate than non-IL-supported Novozym 435, with the highest yield being 67 %. Additionally, glucosylimidazolium iodide (R=CH\({}_{3}\))-supported Novozym 435 had nearly unchanged performance for the tested 10 cycles, lowering to only 62 % from the initial 67 %, marking this IL as the overall best support material for this type of reaction. Designing drug delivery systems for therapeutic compounds whose receptors are located in the cytosol of cells is challenging due to the fact that the bilayer cell membrane is negatively charged. The newly designed drug delivery systems should assist the mentioned drugs in passing the membrane barriers and achieving their targets. A recent study concentrated on developing novel ILs based on glucose-containing choline, which interacts effectively with the cell membranes. ILs are expected to be non-toxic [94]. The following approximations for the development of ILs based on glucose-containing choline cation and drug substances presented in anionic form have been adopted. Thus, [PERSON] et al. developed a drug-based IL (lidocaine-diclofenac IL), which has a developing effect on controlled drug release.