Phytochemical Profiles and Antioxidant Activity of Rehmannia glutinosa from Different Production Locations

The chemical components and antioxidant activity of 16 Rehmannia glutinosa samples were investigated to reveal the high-quality raw resource for pharmaceutical products. 22 main chemical components were detected with significant content differences (P<0.05). The contents of 14 substances reached the maximum in S1 sample such as catalpol (6.74 mg g^-1 ), rehmaionoside A (1.93 mg g^-1 ) and rehmannioside D (5.13 mg g^-1 ). However, the content distribution of the other eight substances had no obvious change regulation. Three antioxidant evaluation methods commonly showed that S1 sample had strong antioxidant activity with a low IC₅₀ value of 0.022 mg mL^-1 , a high ABTS value of 524.196 μmol equiv. Trolox g^-1 , and a high FRAP value of 200.517 μmol equiv. Trolox g^-1 . Considered the medicinal value, S1 had high quality based on the present phytochemical profiles and antioxidant activity. These results also indicated that the root extracts of R. glutinosa could become useful supplement for pharmaceutical products as new antioxidant agents.