Synthesis and sst(2) binding profiles of new [Tyr(3)]octreotate analogs.

One of the main objectives of our current work is the development of new somatostatin analogs that would retain the general characteristics of [Tyr(3)]octreotate (Tate) while showing potential for clinical application. In this respect, study of their interaction with the sst(2) is crucial in providing preliminary structure-activity relationships data. In the present work we report on the synthesis and the preliminary biological evaluation of a total of 15 new structurally modified [Tyr(3)]octreotate analogs. The binding affinities were determined during competition binding assays in sst(2)-positive rat acinar pancreatic AR4-2J cell membranes using [(125)I-Tyr(3)]octreotide as the radioligand.