Determination of Suitable Macroporous Resins and Desorbents for Carnosol and Carnosic Acid from Deep Eutectic Solvent Sage (Salvia officinalis) Extract with Assessment of Antiradical and Antibacterial Activity

In this study, for the first time, the adsorption/desorption characteristics of carnosic acid and carnosol from deep eutectic solvent extract of Salvia officinalis on five macroporous resins (HP20, XAD7HP, XAD16N, HP21, HP2MG) were evaluated. The high adsorption and medium desorption capacities of carnosic acid and carnosol as well as antibacterial and antiradical activity from the extract obtained with choline chloride:lactic acid (1:2) on XAD7HP resin indicated that resin was appropriate. To get the optimal separation process, the influence of factors such as adsorption/desorption time and volume of desorbent was further investigated. The results showed that the extract with high antiradical and antibacterial activity was obtained via adsorption and desorption on XAD7HP resin. The extraction efficiencies of the deep eutectic solvents (DESs) recycled once, twice, and thrice were 97.64% (+/- 0.03%), 93.10% (+/- 0.66%), and 88.94% (+/- 1.15%), respectively, for carnosic acid, and 96.63% (+/- 0.04%), 94.38% (+/- 0.27%), and 91.19% (+/- 0.36%), respectively, for carnosol, relative to the initial solvent efficiency. Based on that, this method is a promising basis for the large-scale preparation of extracts from Salvia officinalis with further application in the pharmaceutical or food industry, especially for maintaining the green character of the whole process to obtain the appropriate extract.

Automated summary

This study evaluated the adsorption/desorption characteristics of carnosic acid and carnosol on five macroporous resins from the deep eutectic solvent extract of Salvia officinalis. The extract obtained on XAD7HP resin showed high antiradical and antibacterial activity, indicating its suitability. Recycling the deep eutectic solvents resulted in high extraction efficiencies for carnosic acid and carnosol.