Large-scale targetedly isolation of biflavonoids with high purity from industrial waste Ginkgo biloba exocarp using two-dimensional chromatography coupled with macroporous adsorption resin enrichment

Seeds and leaves of Ginkgo biloba have been widely applied for industrial application, viewing and medicinal resource. However, the exocarp of G. biloba is usually abandoned and considered as industrial waste. In this work, an efficient and industrially viable protocol for large-scale targetedly isolation of bioactive biflavonoids with high purity from industrial waste G. biloba exocarp was established firstly. Macroporous adsorption resin was used for enriching bioflavonoids, and targeted on-line recognition of biflavonoids was based on their characteristic UV absorption at 210, 270 and 330 nm. Two-dimensional preparative normal phase/reversed phase HPLC-DAC50 system was applied for isolating biflavonoids. A total of 3 biflavonoids including bilobetin, ginkgetin and isoginkgetin were isolated and their purity > 99.0%, dozens or hundreds of milligrams were obtained in one isolation within 30 min. This work will not only provide an effective method for isolating large-scale high purity biflavonoids, but contribute to making full use resources of industrial waste G. biloba exocarp.