Isolation, purification and comparison of soluble active substances from four peony roots

Abstract

Due to high medicinal and economic value of Paeonia L., roots from 4-year-old, 5-year-old, and 6-year-old Paeonia ostii (4PO, 5PO, 6PO), as well as medicinal Paeonia suffruticosa (PS), Paeonia lactiflora (PL) and Paeonia vetchii Lynch (PV) were utilized to isolate and purify soluble activity substances. Through static and dynamic experiments, it was established that LX-83 macroporous resin effectively purified the crude extract of peony root (PR) under optimal conditions: Absorption to the column at 2 BV/h for 6 h, followed by desorption with 60 % ethanol at 5 BV/h for 0.8 h. After purification, the average total phenolic content of six PR crude extracts surged from 147.8 mg GAE/g dry weight (dw) to 397.5 mg GAE/g dw. Eight terpenes, 13 phenols, 6 flavonoids, and 4 tannins in crude PR extracts were identified by HPLC-MS. The content of paeoniflorin, pentagalloylglucose, mudanpioside C, benzoyloxidized paeoniflorin, benzoyl paeoniflorin, and paeonol was determined by HPLC, which increased by 3–5.2 times. The purified PO and PS extracts contain significantly abundant amounts of paeonol and paeoniflorin, exceeding the standards of 1.2 % and 1.6 % in the Chinese Pharmacopoeia, respectively. Moreover, the purified PR extracts exhibited enhanced antioxidant activity and anti-tyrosinase activity, with 5PO and 6PO extracts demonstrating the highest efficacy. This study successfully developed a versatile and effective method for purifying active substances in various PRs. It also provided theoretical and practical insights for upgrading and transforming the root industry of Paeonia plants.