A novel chromatographic separation method for rapid enrichment and isolation of novel flavonoid glycosides from Sphaerophysa salsula

Flavonoid glycosides exist widely in medicine herbs and often used as nutraceuticals because of their excellent bioactivity and low toxicity. For accurate quality control and bioactivity assessment of Sphaerophysa salsula, a rapid and productive method to isolate flavonoid glycosides is needed. Therefore, this work reports the development of a novel comprehensive strategy based on an online middle-pressure chromatography and preparative HPLC for rapid enrichment and separation of flavonoid glycosides from Sphaerophysa salsula. First, the flavonoid glycosides were enriched using an online middle-pressure chromatographic column containing stationary MCI phase. During this process, the high-volume injection of the extracting solution was realized by an empty pre-column positioned before the main chromatographic tower. Then, the compounds were separated through preparative HPLC with Megress C18. As a result, one new flavonol 3-O-glycoside (2) together with two known flavonol 3-O-glycosides (1, 3) were targetedly isolated from Sphaerophysa salsula. The content of compounds 1-3 in Sphaerophysa salsula was 0.09, 0.11, and 0.18 wt%, respectively. Comparing to traditional enrichment and separation methods, our technique offers significantly shorter sample pretreatment time as well as high reproducibility. We believe that our separation method has a strong potential to be used for the processing of other medicinal plants. This article is protected by copyright. All rights reserved.

Keywords: flavonoid glycosides; large volume injection; new compound; online enrichment; preparative chromatography.