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Ultrasound/microwave assisted extraction (UMAE) of flavonoid compounds from Eucommia ulmoides leaves was studied and the extraction conditions were optimized by the Plackett-Burman design (PBD) method combined with the Box-Behnken design (BBD). The antioxidant and antibacterial activities of the flavonoid extract were investigated. The results show that the optimal conditions were an ethanol concentration of 41%, microwave power of 178 W and an ultrasound extraction time of 26 min. Under these conditions, the yield of the flavonoid compounds was 2.454%±0.230%, which was higher than that after direct solvent extraction, ultrasound extraction and microwave extraction. The results of in vitro antioxidant assays showed that the flavonoid extract had scavenging capacity for DPPH, ABTS and hydroxyl radicals, with corresponding IC50 values of 30.76 mg/L, 21.09 mg/L, 248.4 mg/L, respectively. In addition, this extract exhibited strong antibacterial activity on Escherichia coli, Staphylococcus aureus and Salmonella typhimurium.

Dihydromyricetin is a flavonoid compound of dihydroflavone alcohol, which has anti-inflammatory, antioxidant, anti-tumor, antibacterial, hepatoprotective, hypoglycemic, cardiovascular protection and other effects. Dihydromyricetin can be rapidly metabolized, without marked toxicity. At present, Ampelopsis grossedentata, one of the main sources of dihydromyricetin has been included in the food raw materials list, which has not been included in the feed raw materials list and the exploitation and utilization still need to be further expanded. The paper reviews the research progress of anti-inflammatory effect of dihydromyricetin in tissues, organs and cells in vivo and related mechanisms, to provide reference for further research and development of dihydromyricetin. [ABSTRACT FROM AUTHOR]

Objective: To optimize the aqueous two-phase extraction and separation technology of flavonoids from the leaves of Eucommia ulmoides., Methods: The system was prepared by dissolving suitable amounis of polyethylene glycol 4000 (PEG4000) and dextran 40000 ( D40) in aqueous solution. Phase map of the system, the mass fraction of PEG4000 and D40, the effects of amount of added sample, pH value and temperature on target compounds were investigated systematically., Results: The optimum extraction conditions were PEG4000 11%, N40 8%, 8 g sample which contains 6.85% of flavonoids, temperature 60 t and pH value 8. The highest extraction rate could reach to 75.82%., Conclusion: This method has the advantages of mild conditions, solvent-free residues and less time-consumed, and the obvious efficiency in single-stage separation and purification of flavonoids.

The absorption spectroscopic determination of aucubin by condensation with p-dimethylaminobenzaldehyde was optimized in this paper. A high sensitive method was established and the linearity range of the method was from 4.5 to 45 microg x mL(-1). The influences of the factors, such as the dosage of coloring agent, reaction time, heating temperature and the dose of acid etc., on the system were studied. And the result indicated that all of the factors had obvious effects on the system. The method has been applied to determining the content of aucubin in the extract of Eucommia olive with satisfactory results.

Objective: To study the optimum technology of extracting bioactive component named geniposidic acid in Eucommia Ulmiodes by orthogonal test., Method: An orthogonal test table L16(4(5)) was used with the factors of extracting time, temperature, times, ethanol consistency and the ratio of solid to liquid. The content of geniposideic acid was determined by RP-HPLC., Result: The optimum technology was: temperature 50 degrees C, time 1 h, once, consistency 80%, and the ratio of solid and liquid 1:12. Under the condition, the best material of Eucommia Ulmiodes for extracting geniposidic acid was chosen., Conclusion: The technology can provide some theoretic advice for industry.