Isolation of triterpenic acid-rich extracts from Hedyotis corymbosa using ultrasound-assisted supercritical carbon dioxide extraction and determination of their fictitious solubilities

Abstract

Abstract The present study investigated a green ultrasound-assisted supercritical carbon dioxide (USC–CO 2 ) process for extracting oleanolic acid (OA) and ursolic acid (UA) from Hedyotis corymbosa . Chrastil, Bartle and Kumar and Johnston models were used to correlate the experimental fictitious solubility data. The overall average absolute relative deviation ( AARD (%)) in solid solubility ranged from 3.632% to 6.529%, which indicates good agreement between the experimental fictitious solubility data and the modeled results. Using the correlation results, the total heat of solution and the enthalpies of vaporization and solvation for OA and UA in the USC–CO 2 extraction process were also estimated.