Online extraction and isolation of highly polar chemical constituents from Brassica napus L. pollen by high shear technique coupled with high-performance counter-current chromatography

Abstract

High shear technique coupled with high-performance counter-current chromatography was successfully used for the extraction and online isolation of seven highly polar chemical constituents from the Brassica napus L. The lower phase of ethyl acetate-n-butanol-water (1:4:5, v:v:v) was used as both the high shear technique solvent and high-performance counter-current chromatography mobile phase. Seven compounds of 14.2 mg of uridine, 4.6 mg of xanthosine, 7.8 mg of guanosine, 5.3 mg of adenosine, 19.5 mg of kaempferol-3,4'-di-O-β-D-glucopyranoside, 17.7 mg of kaempferol-3-O-(2-O-β-D-glucopyranosy1)-β-D-glucopyranoside, and 25.7 mg of an unknown compound, with a high-performance liquid chromatography (HPLC) purity over 95.0%, were obtained in a one-step extraction-separation process within 130 min from 20.0 g of raw material of pollen of Brassica napus L. Moreover, the mode of elution-extrusion was employed for the separation of the last one compound. The isolated compounds were analyzed by HPLC, and the chemical structures of the compounds mentioned above were identified by UV and NMR. It is the first time to combine the high shear technique and high-performance counter-current chromatography for the online isolation of the nature products.