Table 1 Experimental combinations according to codes of experimental design at various extraction conditions of solvent concentration, reaction temperature, and time

Treatment	Concentration (%)	Temperature (°C)	Time (hr)	Actual parameters
	X1	X2	X3	Concentration (%)	Temperature (°C)	Time (hr)
	1	-1	-1	-1	30	25	5
2	1	-1	-1	90	25	5
3	0.333	0.333	-1	70	55	5
4	-1	1	-1	30	70	5
5	1	1	-1	90	70	5
6	-0.333	-1	-0.333	50	25	7
7	-1	-0.333	-0.333	30	40	7
8	1	0.333	-0.333	90	55	7
9	1	-0.333	0.333	90	40	9
10	0.333	1	0.333	70	70	9
11	-1	-1	1	30	25	11
12	1	-1	1	90	25	11
13	0.333	-0.333	1	70	40	11
14	-0.333	0.333	1	50	55	11
15	-1	1	1	30	70	11
16	1	1	1	90	70	11
17	1	1	1	90	70	11
18	1	1	1	90	70	11