Table 2. Gray correlation coefficients between the active ingredients, antioxidant activity and related environmental factors.

Environmental factors	Correlation degree
	Tannin	Total flavonoids	Rutin	Total phenolics	IC50
XN	0.313	0.456	0.501	0.444	0.478
XAAP	0.351	0.511	0.421	0.602	0.507
XALTI	0.717	0.758	0.661	0.724	0.776
XpH	0.471	0.376	0.357	0.376	0.444
XAAT	0.402	0.413	0.364	0.461	0.305
XAMT	0.357	0.301	0.462	0.598	0.287
XP	0.316	0.406	0.456	0.336	0.321
X7	0.579	0.432	0.477	0.458	0.429
X1	0.481	0.338	0.328	0.294	0.328
XASD	0.357	0.674	0.733	0.328	0.613
XTP	0.322	0.329	0.353	0.422	0.515

X_N, X_P, ···, X_ALTI was performed in the Table 1. IC₅₀ was used to indicate antioxidant activity.