| 摘要 |
Compounds of formula (I) in which R1 is hydrogen or alkyl; R2 is hydrogen or one or more alkyl groups; R3 is R1 or R1X-; wherein R1 is hydrogen or optionally substituted alkyl, aryl, arylalkyl, cycloalkyl or heterocyclyl and X is a linking group; and R4 is hydrogen or alkyl; with the proviso that when R4 is methyl and R3 is methyl or hydroxyethyl then R2 is not hydrogen. Are selective delta opioid receptor ligands and therefore of potential therapeutic utility as analgesics and antihyperalgesics for different pain conditions; immunosuppressants to prevent rejection in organ transplant and skin grafts; 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 and epilepsy. |
