Introduction
Harmful effects of free radicals to the human body have been studied over the last decade. Overproduction of the free radicals can be responsible for tissue injuries that cause many health problems which include cancer, aging, heart diseases, neurological disorders, Alzheimer's disease, Huntington disease and so on. Melatonin (MLT), the main secretory product of the pineal gland is a well-known antioxidant and free radical scavenger. It is a neurohormone produced from the amino acid tryptophan. In our earlier studies, new MLT-based analogues with changes in the 5-methoxy and 2-acylaminoethyl groups of MLT were synthesized and tested for their in vitro antioxidant potency in the DPPH, superoxide dismutase and lipid peroxidation (LP) assays.