Determination of phyllodulcin from sweet hydrangea leaves by subcritical water extraction and high performance liquid chromatographic analysis

The subcritical water extraction was developed for extraction of phyllodulcin, well known as a sweetener in Hydrangea macrophylla var. thunbergii Makino (Saxifragaceae). Several temperatures (50, 100, 125, and 150 degrees C) and static extraction times (5, 10, and 20 min) were studied for optimization of the extraction protocol. The optimized conditions are as follows: temperature, 150 degrees C; static extraction time, 20min. In addition, extraction efficiency of the subcritical water extraction for phyllodulcin was compared with ultrasonic extraction with methanol. The extraction yields of phyllodulcin were 10.41 +/- 2.02 mg/g by subcritical water extraction (temperature, 150 degrees C; static extraction time, 20min) and 17.40 +/- 2.02 mg/g by ultrasonic extraction with methanol. As results in this experiment show, subcritical water extraction was an alternative environmentally friendly extraction method for phyllodulcin in H. macrophylla var. thunbergii.