Extraction optimization study of flavonoids from Humulus lupulus / 中国中药杂志

<p><b>OBJECTIVE</b>To optimize extracting parameters of flavonoids from Humulus lupulus.</p><p><b>METHOD</b>Based on the single factors test on ethanol concentration, material and solvent ratio, extracting temperature and extracting time, orthogonal test was performed and the best combination was confirmed.</p><p><b>RESULT</b>With the optimized technology, the maximal extracting amount of flavonoids from H. lupulus was 78 mg x g(-1).</p><p><b>CONCLUSION</b>The optimal techniques obtained are 45% ethanol extracting at 60 degrees C with material and solvent ratio 1:25 for 90 min.</p>

Optimization of conditions for supercritical fluid extraction of flavonoids from hops (Humulus lupulus L.) / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Waste hops are good sources of flavonoids. Extraction of flavonoids from waste hops (SC-CO(2) extracted hops) using supercritical fluids technology was investigated. Various temperatures, pressures and concentrations of ethanol (modifier) and the ratio (w/w) of solvent to material were tested in this study. The results of single factor and orthogonal experiments showed that at 50 degrees C, 25 MPa, the ratio of solvent to material (50%), ethanol concentration (80%) resulted in maximum extraction yield flavonoids (7.8 mg/g). HPLC-MS analysis of the extracts indicated that flavonoids obtained were xanthohumol, the principal prenylflavonoid in hops.