Ultrasound-assisted Extraction And Microwave-assisted Extraction For Flavones From Euonymus Alatus Sieb

Euonymus alatus Sieb is a plant which has been used as Chinese folkremedies for over 2000 years. The most important bioactive compoundspresent within this medicinal species are flavones including rutin, quercetinand so on. These flavones have shown significant scavenging of free oxygenradicals and anti-decrepitude activity. The therapeutic effects of it such asantimicrobial and antihypertensive have been reported.Determination of total flavones from Euonymus alatus Sieb bymicrowave-assisted extraction and absorption spectroscopy was reported. Theextract conditions were optimized by single factor and orthogonal experiments.Euonymus alatus Sieb twigs, dipped in 40:1 of 60% (v/v) ethanol to twigsweigh ratio, were treated with microwave power of 255 W for 5 min. Underthe optimized condition, parallel experiments and recovery experiments werecompleted. The relative standard deviation is 1.711% (n=5) and the recoveryis 97～101%. This method was simple and accurate with good reproducibility,and is suitable for the determination of flavonoids in many kinds of traditionalChinese medicines.An ultrasonic method for the extractions of rutin and quercetin from Euonymus alatus Sieb. was investigated. The influence of four extractionvariables on extraction yield of rutin and quercetin was discussed. Theoptimum extraction conditions found were: 70% aqueous ethanol; solvent:sample ratio 40:1 (v/w); extraction time 3×30 rain. The recovery of rutinand quercetin and the reproducibility of the extraction method weredetermined. The application of sonication method was shown to be highlyefficient in the extraction of rutin and quercetin from Euonymus alatus Siebcompared with maceration.A detail procedure for extracting rutin and quercetin from Euonymus alatusSieb was developed by using an obturated microwave-assisted extraction(MAE) device with pressure and temperature controlling units. The effects ofsolvent concentration, rate of solution to solid, radiation time and microwavepower were discussed by orthogonal experiments. Compared with Soxhletextraction and ultrasonic extraction, microwave extraction was a rapid methodwith a higher yield and less solvent consumption.The mechanism of the microwave-assisted extraction was studied byscanning electronic micrograph (SEM). In the case of microwave heating, thepressure build-up within the cells could have exceeded their capacity forexpansion, and caused their rupture more rapidly than in conventionalextraction.