Table 1 Extraction methods for different specifications of DC

Fresh stems (FS)

1. Boiling

2. Infusion

3. Brewing

1. Distilled water

2. Distilled water

3. 45% ethanol

1. 100 °C

2. 90 °C as initial temperature (cool under room temperature)

3. Room temperature

1. 4 h

2. 4 h, 6 h and 8 h

3. 168 h, 336 h and 504 h

Dried stems (DS)

Fengdou (FD)

Powder (P)

1. Boiling

2. Infusion

1. Distilled water

2. Distilled water

1. 100 °C

2. 90 °C as initial temperature (cool under room temperature)

1. 4 h

2. 4 h, 6 h and 8 h