C. Gilon et al., A BACKBONE-CYLIC, RECEPTOR 5-SELECTIVE SOMATOSTATIN ANALOG - SYNTHESIS, BIOACTIVITY, AND NUCLEAR-MAGNETIC-RESONANCE CONFORMATIONAL-ANALYSIS, Journal of medicinal chemistry, 41(6), 1998, pp. 919-929
Cyclo(PheN2-Tyr-D-Trp-Lys-Val-PheC3)-Thr-NH2 (PTR 3046), a backbone-cy
clic somatostatin analogue, was synthesized by solid-phase methodology
. The binding characteristics of PTR 3046 to the different somatostati
n receptors, expressed in CHO cells, indicate high selectivity to the
SSTR5 receptor. PTR 3046 is highly stable against enzymatic degradatio
n as determined in vitro by incubation with rat renal homogenate and h
uman serum. The biological activity of PTR 3046 in vivo was determined
in rats. PTR 3046 inhibits bombesin-and caerulein-indueed amylase and
lipase release from the pancreas without inhibiting growth hormone or
glucagon release. The major conformation of PTR 3046 in CD3OH, as det
ermined by NMR, is defined by a type II' beta-turn at D-Trp-Lys and a
cis amide bond at Val-PheC3.