Behavioural actions of two new 1-N substituted analogues of melatonin.

Melatonin has been mainly used for alleviating some disorders related with insomnia and circadian rhythmicity. The use of this hormone has been limited, among others, due to its short half-life and instability. This study reports some behavioural actions of two new melatonin analogues that incorporate a phenyl or a benzoyl group at the nitrogen atom of the melatonin molecule. Although diazepam was about 10 times more potent than either of the melatonin analogues, results show that in general these last display better anxiolytic, anticonvulsant and sedative actions than the original molecule.