ABSTRACT
Objective To compare the antioxidant activity between phenolic and nonphenolic alkaloids in Nelumbo Nucifera Gaertn.in vitro. Methods DPPH, ABTS, hydroxyl radical scavenging, super oxygen anion from oxidation, reducing power and beta carotene bleaching test methods were used to evaluate the antioxidant activity of the alkaloids. Results Half maximalinhibitory concentration ( IC50 ) of DPPH among total alkaloid, phenolic alkaloids and nonphenolic alkaloids was 21.89, 27.10 and 32.87 μg·mL-1 , respectively;IC50 of ABTS free radicals was 14.25, 20.55, 25.94μg·mL-1;The hydroxyl radical scavenging IC50 was 0.03, 0.03, 0.08 μg·mL-1; The auto-oxidation rate of super oxygen was 8.72×10-4, 5.87×10-4, 6.68× 10-4;The total alkaloid had the best reducing power, while the non-phennolic alakloids had the worst; Lipid inhibition rate of three alkaloids were 89.63%, 85.85% and 83.78% respectively. Conclusion Phenolic alkaloids are better than non-phenolic alkaloids in hydroxyl radical scavenging, reducing power and anti-lipid peroxidation, resulting in a promising prospect.