Table 1 Contributions of the 21 candidate indices to the SVM-based prediction model

Licorice saponin G2

0.94

Liquiritigenin

8.01

Licoflavonol

2.55 × 10⁻²

Glycyrrhizic acid

4.86

Violanthin

2.06 × 10⁻²

Alcohol-soluble extract

1.15

Formononetin

3.17 × 10⁻²

Isoliquiritin apioside

0.44

Diameter

12.73

Semilicoisoflavone B

3.33 × 10⁻²

Isoliquiritin isomer

3.39 × 10⁻²

Pharmacological activity index

14.52

Licoisoflavone B

0.72

Isoliquiritin

0.51

Total flavonoid content

26.14

Liquiritin apioside

4.83

Neoisoliquiritin

0.23

HPLC fingerprint chromatogram similarity (250 nm)

2.18

Liquiritin

20.07

Glycyrol

5.00 × 10⁻³

HPLC fingerprint chromatogram similarity (330 nm)

2.52