Bombesin receptor antagonists. 4. Chloromethylketone and chloroethylnitrosourea derivatives

Abstract

Four alkylating bombesin (BN) analogues (two C-terminal and one N-terminal chloromethylketone derivatives, and one chloroethylnitrosourea derivative) were synthesized and tested in Swiss 3T3 fibroblasts for receptor binding and mitogenic activity. Although they bound to the BN receptor with no or very weak mitogenic activity, no one analogue inhibited BN-induced thymidine incorporation in the contemporaneous treatment; only one behaved as a weak receptor antagonist when given 24 h before BN stimulation.