Enhance solubility of bioactive compounds via addition of polymers or ionic liquids

Abstract

One of the major challenges in the isolation and utilization of bioactive compounds (BACs) is their poor solubility in water. Increasing solubility, and thereby enhancing their extraction efficiency from biomass, is often achieved through the addition of chemical agents such as organic solvents and surfactants. However, these agents are frequently toxic, which drives the need for alternative, less harmful or non-toxic solutions. The aim of this work was to improve the solubility of two groups of BACs—parthenolide and phenolic compounds from Tanacetum parthenium flowers, by adding polymers, and ellagic acid and phenolic compounds from raspberry pomace, by adding ionic liquids. Our results demonstrate that the extraction yield strongly depends on both the biomass particle size and the use of selected additives. Smaller particles, due to improved contact with the solvent, provided significantly higher yields. To enhance the yield of parthenolide, a hydrophobic compound, we employed the polymer PPG 400. Increasing the PPG 400 concentration from 1 to 15% raised the parthenolide yield from 2.6 to 4.6 mg/g (Figure 1). Figure 1 demonstrates that the maximum yield of parthenolide is achieved through extraction with ethanol; however, the concentration of total phenols is five times higher when using 15% PPG 4000 compared to ethanol. The most pronounced effect on ellagic acid extraction was observed with surface-active ionic liquids, which increased the yield up to fivefold compared to water. These findings highlight the potential of polymers and ionic liquids as green and efficient alternatives for improving the solubility and extraction of poorly water-soluble bioactive compounds. Such approaches open new perspectives for sustainable isolation of natural products with enhanced applicability in pharmaceuticals and functional foods.