Synthesis and cytotoxic activity of Boc-protected pentapeptide amide analogs of somatostatin

New Boc-protected pentapeptide amides of the general formula Boc—Cys(Boc)—Phe—d-Trp—Lys(Boc)—Thr—NHR, which are analogs of the natural hormone somatostatin, were synthesized. The cytotoxic activity of the new compounds was evaluated against the cancer cell lines MCF-7, PC 3, and HCT-116 by the MTT test, and some of these compounds were found to exhibit activity at micromolar concentrations.