Extracting phenolics, flavonoids, and terpenoids from Codonopsis pilosula using green solvents

Abstract

This research aimed to extract bioactive compounds from Codonopsis pilosula Franch using natural deep eutectic solvents (NADES) combined with single and combined extraction methods. This work also depicted the kinetics of single and combined extraction methods. Among the six different NADES formulations devised, it was determined that the most effective one for extracting phenolics, flavonoids, and terpenoids was the combination of lactic acid and glucose in a 2:1 M ratio. The study then examined the impact of microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE), and ultrasonic-microwave-assisted extraction (UMAE) using NADES on the extraction of flavonoids, terpenoids, and phenolics. After that, the second-order model was used to describe the extraction kinetic of NADES-based UAE, MAE, and UMAE processes before the bioactive compounds and antioxidant activities of extracts were employed to evaluate the extraction efficiency of the three methods. UMAE showed the most effective extraction technique in exploiting the bioactive compounds from C. pilosula. At the favorable parameters of NADES-based UMAE, the levels of phenolics, flavonoids, and terpenoids were 30.98 ± 1.1 mg GAE/g db, 24.36 ± 0.48 mg RE/g db, and 185.47 ± 4.39 mg UA/g db, respectively. This study gave a sustainable method for recovering phenolics, flavonoids, and terpenoids from C. pilosula and was the first step in developing pharmaceutical products.