Abstract: Compounds, or solvates or salts thereof, of formula (I):
selective delta opioid agonists and antagonists and may be of therapeutic utility as analgesics, immunosuppressants to prevent rejection in organ transplant and skin graft, anti-allergic and anti-inflammatory agents, brain cell protectants, agents for treating drug and alcohol abuse, gastritis, diarrhoea, cardiovascular and respiratory diseases, cough, mental illness, epilepsy and, in general, agents for the treatment of those pathological conditions which, customarily, can be treated with agonists and antagonists of the delta opioid receptor.