Correlation coefficients between the data of 57 chemicals and the four bioassays. (a) Fifty-four peaks in typical HPLC fingerprints of DBT. In the HPLC fingerprint of 203 nm, astragaloside IV and other 16 peaks had a retention time between 70 to 120 min. In the HPLC fingerprint of 254 nm, ferulic acid, calycosin, formononetin, ligustilide and other 32 peaks had a retention time between 0 to 70 min. The 54 peaks are numbered, where astragaloside IV (1), ferulic acid (19), calycosin (33), formononetin (50) and ligustilide (53) are identified and served as standards. (b) The correlation coefficients between the data of 57 chemicals with the four bioassays. The correlation coefficient is in Y-axis and the peak number is in X-axis. Individual chemical markers are indicated by arrowheads and denoted by astragaloside IV (A), ferulic acid (B), calycosin (C), formononetin (D), ligustilide (E), total saponins (F), total flavonoids (G) and total polysaccharides (H). All correlations were tested to be statistically significant (P < 0.05).