In this chapter, preparation, basic properties, and some applications of ionic liquids composed of naturally-derived ions are summarized. There are many candidate ions in nature suitable for ionic liquid preparation. Physicochemical properties and preparation of some ionic liquids based on carboxylate anions, cholinium cation, and even amino acids are mentioned. Some interesting applications based on these ionic liquids composed of naturally-derived ions are also briefly introduced. Graphical Abstract.
Keywords: Amino acids; Biological membrane; Carboxylic acids; Hydrophobicity; Polarity; Proteins.