Table 1.

Linear range, regression equations, LOD, and LOQ for quantitative analysis of HPLC (n = 3).

Compound	T R (min)	λ (nm)	Linear range (µg/mL)	Regression equationa	R 2	LOD (µg/mL)	LOQ (µg/mL)
Shaftoside	22.79	271, 337	20.0–200	y = 28370x − 230484	R 2 = 0.999	0.2	0.6
Orientin	25.58	255, 349	0.8–100	y = 27655x − 27061	R 2 = 0.996	0.4	0.8
Isovitexin	27.16	269, 337	0.8–100	y = 34067x + 47328	R 2 = 0.999	0.4	0.8
Vitexin	28.61	268, 337	0.8–100	y = 29217x + 33931	R 2 = 0.997	0.4	0.8

^a y = ax + b, where x is concentration in µg/mL and y is area under curve at UV 330 nm wavelength.