Study on Extraction Optimization of Anti-oxidants from Roots of Angiopteris fokiensis Hieron.

This study was performed to clarify the antioxidant capacity and components of roots of Angiopteris fokiensis. With Vitamin C equivalent antioxidant capacity (VCEAC) as the index, single factor experiments combined with orthogonal tests were carried out to optimize the extraction process of antioxidant components. The antioxidant capacity was also evaluated based on DPPH and ABTS radical scavenging assays. The chromogenic method of NaNO₂-Al(NO₃)₃-NaOH and Folin-phenol was employed separately to determine the content of total flavonoids and total phenols, of which the correlation with VCEAC values was then analyzed based on Pearson method. The results demonstrated that the optimal extraction conditions were as follows: No.3 sieve, feed liquid ratio was 1:40 g/mL, volume fraction was 50%, extraction temperature was 60 ℃. Under these conditions, the sample was extracted with antioxidant capacity equivalent to 24.44 mg V_C. The antioxidant capacity differed significantly between 11 batches of A. fokiensis: VCEAC values ranged from 9.41 to 29.32 mg/g; IC₅₀ values ranged from 0.85 to 3.03 mg/mL determined by DPPH assay, and from 1.02 to 3.81 mg/mL determined by ABTS assay. The content of total flavonoids and total phenols ranged from 8.75 to 30.18 mg/g, and from 5.19 to 17.84 mg/g, respectively. The pearson analysis indicated that the content of total flavonoids or total phenols was correlated significantly with the VCEAC values of A. fokiensis (P<0.05). In conclusion, total flavonoids and total phenols in A. fokiensis were determined as the main antioxidant components with potential for further development.