Studies on the chemical change in the process of microwave-assisted extraction of flavonoids from acanthopanax senticosus harms

In the process of microwave assisted extraction(MAE), the chemical changes of the flavonoids in Acanthopanax Senticosus Harms were studied by HPLC-UV and HPLC-ESI-MSn. The influences of pressure and MAE time on the chemical changes were investigated. The experimental results demonstrate that rutin in the extract can be partly decomposed when pressure is over 300 kPa, as a result, the content of quercetin increases by the loss of rutinosyl from rutin. With the increase of microwave extraction time, extraction yields of hyperin, rutin, quercitrin and quercetin are firstly increased and then decreased. The higher the pressure is, the faster the extraction rate and the decomposition rate are, the shorter the extraction time for obtaining the highest yield is.