Antioxidant activities of phenolic compounds from Angelica gigas Nakai extract using subcritical water

Subcritical water extraction can be used to selectively extraction compounds by varying the temperature-dependent dielectric constant of water. This study investigated subcritical water extraction of decursin and nodakenin yields from Angelica gigas Nakai (AN) quantitatively and qualitatively by HPLC, and HPLC-ESI/MS. Total phenolics, total flavonoid contents, and antioxidant activity were determined by DPPH and ABTS radical scavenging activity, including the effects of varying the extraction conditions of temperature (110-200°C) and time (1-20 min) under high pressure (10 MPa). By subcritical water extraction under operating conditions of 120-130°C, the maximum yields of decursin (6.64±;0.42% in the dried material) and nodakenin (3.71±;0.28% in the dried material) were obtained. From 190-200°C the maximum yields of total phenolics (75.97±;1.64 mg gallic acid equivalent/g AN), flavonoids (8.56±;1.10 mg quercetin equivalent/g AN), DPPH (63.07±;1.71%), and ABTS (72.32±;2.82%) were obtained.