Figure 8
Hypothetical model of thymol nanoemulsion. Hydrophilic part of saponin consisted of glucuronic acid, galactose, xylose, rhamnose and fucose; R1-R4: H or alkyl group (blue rectangle) protruding to aqueous phase. Hydrophobic part of saponin that is triterpene sapogenin (red rectangle) remained toward thymol molecules. Carboxylate group (-COO−) of glucuronic acid mainly provides negative surface charge in thymol nanoemulsion. The structure of Quillaja saponin is adapted from reference (Wojciechowski et al.)52 with copyright permission from Elsevier.
