Optimization of Extraction Technology by Response Surface Methodology and Preliminary Structural Characterization of the Composition in Flavonoids from Artemisia capillaris

The ultrasound-assisted extraction technology of the flavonoids from Artemisia capillaris was optimized and its structural characterization of the composition were studied in this paper. On the basis of investigating the effect of extraction time,extraction temperature,ethanol concentration and liquid-to-material ratio on the yield of the flavonoids from Artemisia capillaris,the Box-Behnken response surface method was used to optimize the extraction process,and the prediction model of two polynomial regression equations was simulated. The compounds in extract purified by NKA-9 resin were identified by FT-IR and LC-MS. As a result,the optimal extraction process was as follows:extraction temperature of 61 ℃,ethanol concentration of 48%,liquid-to-material ratio of 30:1 (mL:g). Under these conditions,the total flavonoids content was 24.89 mg/g. By comparing the FT-IR spectra of the purified extracts of Artemisia capillaris and the standard rutin,it showed that vibrational absorption peaks of C=C,hydroxyl group,phenolic hydroxyl group and other characteristic functional groups were found in the purified extracts of Artemisia capillaris,which indicated that the extracts had the typical structure of flavonoids and the existence of rutin monomers. LC-MS was used to analyze the constituents of flavonoids in the extract. It was inferred that the extract contained rutin,hyperin,isoquercetin,isorhamnetin-3-O-glucoside and diosmin by comparing m/z value and retention time. The optimal extraction process of total flavonoids from Artemisia capillaris which were established by the regression data model of response surface methodology was practical and effective. It was also found that the extracts might contain rutin,hyperin,isoquercetin,isorhamnetin-3-O-glucoside and diosmin,which can provide reference for the further study of the extract of Artemisia capillaris.