Table 2.

Quantification of four bioactive components in methanol extract of GD

Bioactive components	Linear regression equations	Correlation coefficients (R2)	Contents (mg/g GD powder)
Chlorogenic acid	y = 381,854.86597 + 57,440,112.13043×	0.99884	5.57 ± 0.35
3, 4-dicaffeoylquinic acid	y = −27,745.44883 + 68,618,107.60542×	0.99988	0.67 ± 0.08
3, 5-dicaffeoylquinic acid	y = 250,500.51458 + 78,350,260.14366×	0.99905	10.29 ± 0.74
4, 5-dicaffeoylquinic acid	y = 26,676.51400 + 9,837,283.14720×	0.99975	6.84 ± 0.14