Table 1. Operating condition of HPLC for 6, 8, 10 gingerol and shogaol

Parameters	Operating condition
HPLC system	Nexera X2 SHIMADZU, UPLC
Detector	DAD, UV, 280 nm
Column	Kinetex XB.C18 100 Å (1.7 μm, 150 × 2.1 mm)
Mobile phase	A: 0.1% acetic acid in water (V/V, %)B: 0.1% acetic acid in acetonitrile (V/V, %)
Gradient elution	Time (min)	A (%)	B (%)
	0.5	90	10
	2.5	60	40
	4.5	45	55
	6.0	40	60
	8.0	35	65
	9.5	35	65
	11.5	35	65
	13.0	30	70
	14.5	25	75
	16.0	20	80
	17.5	15	85
	20.0	10	90
	25.0	10	90
	26.0	90	10
	29.0	90	10
Injection volume (μL)	2
Flow rate (mL/min)	0.3
Column temp. (°C)	30