J Food Bioact

Journal of Food Bioactives, ISSN 2637-8752 print, 2637-8779 online

Journal website www.isnff-jfb.com

Original Research

Volume 19, September 2022, pages 154-163

Optimization of ultrasonic-assisted extraction of bioactive compounds from Bupleuri Radix by response surface methodology and HPLC analysis

Figure 1. HPLC-PDA chromatograms of (a) standard substances, (b) raw Bupleuri Radix (RBR) sample solution, and (c) vinegar-baked Bupleuri Radix (VBBR) sample solution.

Figure 2. The effect of methanol-water proportion (a), solvent-to-solid ratio (b), and extraction time (c) on the yield of six compounds (n = 3).

Figure 3. Response surface (3D) and contour plots (2D) show the effect of different extraction parameters (X₁: proportion of methanol-water, %; X₂: solvent-to-solid ratio, v/w; X₃: extraction time, min) on the response yield.

**Table 1.** RCFs of each analyte in Bupleuri Radix
RCFs	Concentration numbers	Mean ± SD, n = 6	RSD^a (%)
^aRSD (%) = 100 × SD/mean.
1	1.104	1.103	1.102	1.103	1.101	1.103	1.103 ± 0.001	0.081
2	1.300	1.300	1.300	1.300	1.300	1.300	1.300 ± 0.001	0.013
3	1.000	1.000	1.000	1.000	1.000	1.000	1.000 ± 0.000	0.000
4	1.085	1.085	1.085	1.085	1.085	1.085	1.085 ± 0.001	0.016
5	0.975	0.975	0.975	0.975	0.974	0.967	0.973 ± 0.003	0.338
6	0.863	0.863	0.862	0.862	0.862	0.855	0.861 ± 0.003	0.343

Table 1. RCFs of each analyte in Bupleuri Radix

RCFs

Concentration numbers

Mean ± SD, n = 6

RSD^a (%)

^aRSD (%) = 100 × SD/mean.

1.104

1.103

1.102

1.103

1.101

1.103

1.103 ± 0.001

0.081

1.300

1.300 ± 0.001

0.013

1.000

1.000 ± 0.000

0.000

1.085

1.085 ± 0.001

0.016

0.975

0.974

0.967

0.973 ± 0.003

0.338

0.863

0.862

0.855

0.861 ± 0.003

0.343

**Table 2.** Results comparing ESM and QAMS method (Mean ± SD, n = 3)
Analyte	ESM	QAMS	RSD^a (%)
^aRSD (%) = 100 × SD/mean.
1	2.036 ± 0.027	2.037 ± 0.027	1.171
2	2.224 ± 0.017	2.222 ± 0.017	0.674
3	11.936 ± 0.078	11.936 ± 0.078	0.583
4	0.660 ± 0.002	0.659 ± 0.002	0.343
5	1.339 ± 0.010	1.338 ± 0.010	0.695
6	13.423 ± 0.003	13.400 ± 0.003	0.096

Table 2. Results comparing ESM and QAMS method (Mean ± SD, n = 3)

Analyte

ESM

QAMS

RSD^a (%)

Content (mg/g)

^aRSD (%) = 100 × SD/mean.

2.036 ± 0.027

2.037 ± 0.027

1.171

2.224 ± 0.017

2.222 ± 0.017

0.674

11.936 ± 0.078

0.583

0.660 ± 0.002

0.659 ± 0.002

0.343

1.339 ± 0.010

1.338 ± 0.010

0.695

13.423 ± 0.003

13.400 ± 0.003

0.096

**Table 3.** Box–Behnken experimental design and results
Run number	Coded levels	Extraction yield (mg/g)
1	−1	1	0	23.908	23.777
2	−1	−1	0	19.693	19.825
3	0	0	1	18.243	17.951
4	1	1	0	15.947	16.587
5	0	0	−1	23.144	22.505
6	0	0	0	31.203	31.232
7	1	−1	0	31.252	31.232
8	0	0	0	31.250	31.232
9	0	0	−1	22.481	22.134
10	0	0	1	31.223	31.232
11	1	0	0	25.404	25.244
12	1	0	0	31.233	31.232
13	0	1	−1	22.472	22.632
14	−1	0	0	24.717	25.195
15	−1	0	0	26.365	26.712
16	0	−1	−1	26.189	26.481
17	0	1	1	24.334	23.855

Table 3. Box–Behnken experimental design and results

Run number

Coded levels

Extraction yield (mg/g)

X₁

X₂

X₃

Proportion of ethanol-water (%)

Solvent-to-solid ratio (v/w)

Extraction time (min)

Experimental

Predicted

−1

23.908

23.777

−1

19.693

19.825

18.243

17.951

15.947

16.587

−1

23.144

22.505

31.203

31.232

−1

31.252

31.232

31.250

31.232

−1

22.481

22.134

31.223

31.232

25.404

25.244

31.233

31.232

−1

22.472

22.632

−1

24.717

25.195

−1

26.365

26.712

−1

26.189

26.481

24.334

23.855

**Table 4.** ANOVA of response surface quadratic model analysis for the extraction yield
Source	SS^a	DF^b	MS^c	F-value	P-Value
RMSE = 0.243; R² = 0.995; R_adj² = 0.989; C.V.% = 1.995. ^aSums of squares. ^bDegree freedom. ^cMean square.
Model	368.567	9	40.952	161.567	<0.0001
X₁	48.708	1	48.708	192.166	<0.0001
X₂	25.847	1	25.847	101.972	<0.0001
X₃	1.933	1	1.933	7.628	0.0280
X₁X₂	5.333	1	5.333	21.039	0.0025
X₁X₃	5.086	1	5.086	20.064	0.0029
X₂X₃	0.235	1	0.235	0.927	0.3677
X₁²	136.048	1	136.048	536.748	<0.0001
X₂²	19.958	1	19.958	78.741	<0.0001
X₃²	100.056	1	100.056	394.748	<0.0001

Table 4. ANOVA of response surface quadratic model analysis for the extraction yield

Source

SS^a

DF^b

MS^c

F-value

P-Value

RMSE = 0.243; R² = 0.995; R_adj² = 0.989; C.V.% = 1.995. ^aSums of squares. ^bDegree freedom. ^cMean square.

Model

368.567

40.952

161.567

<0.0001

X₁

48.708

192.166

<0.0001

X₂

25.847

101.972

<0.0001

X₃

1.933

7.628

0.0280

X₁X₂

5.333

21.039

0.0025

X₁X₃

5.086

20.064

0.0029

X₂X₃

0.235

0.927

0.3677

X₁²

136.048

536.748

<0.0001

X₂²

19.958

78.741

<0.0001

X₃²

100.056

394.748

<0.0001