Abstract: Octopamine is a natural β-3-adrenergic receptor agonist(β-3-ARA).In the previous literature its biological activity focused on the preventive function on obesity and typeⅡdiabetes.Previous researches found that tyramine,the precursor compound of octopamine,had comparative high antioxidant activity in concentrationdependent manner.In this paper ten derivatives of octopamine were synthesized.The antioxidant activity of octopamine,tyramine as well as octopamine derivatives were then tested by investigating their scavenging effect against DPPH free radicals,superoxide anion radicals and hydroxyl free radicals.It was showed that the scavenging rate of octopamine and its two derivatives,OA07 and OA08 against the above free radicals were higher than that of tyramine.OA05,another octopamine derivative,had prominent scavenging effect against superoxide anion radicals,which was worthy of further study.

Key words: octopamine, derivative, tyramine, antioxidant activity