Two Novel Proline-Containing Catechin Glucoside from Water-Soluble Extract of Codonopsis pilosula.

Choushenflavonoids A () and B (), two unusual proline-containing catechin glucosides, were isolated from the roots of cultivated in a high-altitude location of Yunnan province. Their structures were determined by spectroscopic data and chemical methods. Specifically, the absolute configuration of glucose residue in and was assigned by acid hydrolysis followed by derivatization and gas chromatography (GC) analysis. In addition, biological evaluation of and against Sirtuin 1 (SIRT1) was carried out.