Novel tetrapeptidesemicarbazide derivatives, inclusive of a pharmacologically acceptable salt thereof, which has the general formula (I):
wherein R1 is hydrogen or lower alkyl; R2 is hydrogen or a D-α-amino acid side chain; R3 is hydrogen or lower alkyl; X is oxygen or sulfur, are useful as analgesics.
具有通式(I)的新型四肽emicarbazide 衍
生物,包括其药理学上可接受的盐:
其中 R1 为氢或低级烷基;R2 为氢或 D-
α-氨基酸侧链;R3 为氢或低级烷基;X 为氧或
硫,可用作镇痛剂。