Isolation and quantitation of amygdalin in Apricot-kernel and Prunus Tomentosa Thunb. by HPLC with solid-phase extraction

Apricot-kernel and Prunus Tomentosa Thunb. are traditional Chinese herb medicines that contain amygdalin as their major effective ingredient. In this report, three methods for the extraction of amygdalin from the medicinal materials are compared: ultrasonic extraction by methanol, Soxhlet extraction by methanol, and reflux extraction by water. The results show that reflux extraction by water containing 0.1% citric acid is the best option. The optimal reflux time is 2.5 h and water bath temperature is 60° C. The solid-phase extraction method using C18 and multiwalled carbon nanotube as adsorbents is established for the pretreatment of reflux extract, and the result shows that the two adsorbents have greater adsorptive capacity for amygdalin and good separation effect. In order to quantitate amygdalin in Apricot-kernel and Prunus Tomentosa Thunb., a reversed-phase high-performance liquid chromatography method using methanol-water (15:85, for 30 min and pure methanol after 30 min) as mobile phase is developed and a good result is obtained.