In this work, flavonoid fraction from the leaves of Crataegus pinnatifida was separated into its seven main constituents using a combination of HSCCC coupled with pre-HPLC. In the first step, the total flavonoid extract was subjected to HSCCC with a two-solvent system of chloroform/methanol/water/n-butanol (4:3:2:1.5, v/v), yielding four pure compounds, namely (–)-epicatechin (1), quercetin-3-O-(2,6-di-α-l-rhamnopyranosyl)-β-d-galactopyranoside (2), 4′′-O-glucosylvitexin (3) and 2′′-O-rhamnosylvitexin (4) as well as a mixture of three further flavonoids. An extrusion mode was used to rapidly separate quercetin-3-O-(2,6-di-α-l-rhamnopyranosyl)-β-d-galactopyranoside with a big KD-value. In the second step, the mixture that resulted from HSCCC was separated by pre-HPLC, resulting in three pure compounds including: vitexin (5), hyperoside (6) and isoquercitrin (7). The purities of the isolated compounds were established to be over 98%, as determined by HPLC. The structures of these seven flavonoids were elucidated by ESI-MS and NMR spectroscopic analyses.

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We put forward an efficient strategy based on bioassay guidance for the rapid screening, identification, and purification of the neuraminidase inhibitors from traditional Chinese medicines, and apply to the discovery of anti-influenza components from Lithospermiun erythrorhizon Sieb.et Zucc. Ultrafiltration with high-performance liquid chromatography and electrospray ionization time-of-flight mass spectrometry was employed for the rapid screening and preliminarily identification of anti-influenza components from Zicao. Semipreparative high-performance liquid chromatography was used for the rapid separation and purification of the target compounds. NMR spectroscopy, mass spectrometry, and UV spectroscopy were used for further structural identification, and the activity of the compounds was verified by in vitro assay. Five compounds were found to have neuraminidase inhibitory activity by this method. Subsequently, the five compounds were separated by semipreparative high-performance liquid chromatography with the purity over 98% for all of them by high-performance liquid chromatography test. Combined with the NMR spectroscopy, mass spectrometry, and UV spectroscopy data, they were identified as alkannin, acetylalkannin, isobutyrylalkannin, β,β-dimethylacryloylalkannin and isovalerylalkannin. The in vitro assay showed that all five compounds had good neuraminidase inhibitory activities. These results suggested that the method is highly efficient, and it can provide platform and methodology supports for the rapid discovery of anti-influenza active ingredients from complex Chinese herbal medicines.

In this work, surface molecularly imprinted polymers with dummy templates were developed as the selective sorbents for preparation of dencichine from the extract of Panax notoginseng for the first time.The polymers were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The performances of molecularly imprinted and non-imprinted polymers were evaluated, which included selective recognition, adsorption isotherms and adsorption kinetics. Optimization of various parameters affecting molecularly imprinted solid phase extraction, such as sample loading pH and flow rate, the composition and volume of the eluting solvent and the composition and volume of the washing solvent were investigated. Compared with NISPE, MISPE displayed improved specific adsorption performance. Dencichine with a purity of 98.7% was obtained from the aqueous extract of Panax notoginseng with the average recovery of 83.7% (n ¼ 3).