Abstract:

Nine macroporous resins were investigated with respect to their adsorption and desorption rates for the
polyphenol extracted from Morchella angusticepes Peck in order to find the most appropriate one. Response surface
methodology was utilized to establish a mathematical regression model for optimizing the purification of the crude extract by
adsorption column chromatography with the selected resin. NKA-Ⅱ was found to be the most suitable resin for the purification of
polyphenol. The optimum conditions for purification were obtained when the sample containing 295.86 μg/mL polyphenol at pH
2.84 was loaded onto the column at a flow rate of 1.90 mL/min, and then eluted with 78.56% aqueous ethanol acidified to pH 3.08
at a flow rate of 0.80 mL/min. The purification process yielded an adsorption rate of 98.69%, a desoprtion rate of 92.75% and a
purification factor of approximately 4. The half maximal effective concentrations (EC50) for DPPH and ABTS radical scavenging
capacities and reducing power of the crude extract were 1.48, 0.015 and 2.35 mg/mL and reduced to 0.52, 0.004 and 0.69 mg/mL
after the purification, suggesting a significant increase in the antioxidant activities.

Key words: polyphenols from Morchella angusticepes Peck, macroporous resin, NKA-Ⅱ, response surface methodology, antioxidant activity