Practically complementary size exclusion chromatography and reversed-phase liquid chromatography for the preparative separation of structurally similar flavone-C-glycosides

Abstract

In this study, a practicably complementary size exclusion chromatography and reversed-phase liquid chromatography method was constructed and applied to efficiently separate and purify structural analogs or isomers from natural products. First, a ternary styrene–divinylbenzene matrix CHP20P medium–pressure elution system was applied for Ligustrum qianluoenenst leaf crude sample pretreatment, with a recovery of 91.2 %, and 13.0 g of the target fraction Fr4 was obtained. A complementary HW-40C SEC and ReproSil-Pur C18 AQ RPLC system was subsequently constructed by optimizing the HW-40C separation conditions and ReproSil-Pur C18 AQ analysis. Finally, the established complementary SEC and RPLC method was used for the separation and purification of compounds from Ligustrum qianluoenenst leaf target fraction Fr4, and 12 flavone-C-glycosides were successfully prepared with purities exceeding 95 %. The overall methodologies established for flavone-C-glycoside preparative isolation have the potential to maximize the possibility of discovering more structural analogs, including new structural analogs or isomers from natural products.