Abstract
Triprolines Pro-Pro-Pro-NH
2 (
4), Pro-Pro-
d-Pro-NH
2 (
5),
Pro-Pro(trans-3-
Me)-
d-Pro-NH
2
(
6), and
Pro-Pro(cis-3-
Me)-
d-Pro-NH
2
(
7) were made as conformationally constrained analogues of Pro-Leu-Gly-NH
2. Triprolines
4–6 produced significant increases in the high- and low-affinity state ratio (
R
H
R
L
) of the dopamine receptor, but only
4 was found to increase apomorphine induced rotations in 6-hydroxydopamine-lesioned rats.
Conformationally constrained Pro-Leu-Gly-NH
2 triproline analogues
4 (R = H, ∗ =
l),
5 (R = H, ∗ =
d), and
6 (R =
trans-CH
3, ∗ =
d) significantly increased the high-and low-affinity state ratio (
R
H
R
L
) of the dopamine receptor. Only
4, however, was found to increase apomorphine induced rotations in 6-hydroxydopamine-lesioned rats.