Identification of potent 5-pyrimidinyl-2-aminothiazole CDK4, 6 inhibitors with significant selectivity over CDK1, 2, 5, 7, and 9.
5-Pyrimidinyl-2-aminothiazole 1 was identified as an inhibitor of cyclin-dependent kinases (CDKs) by a screening of the Merck sample repository. The introduction of a methyl group at the C-5 or C-6 position on the pyrimidine ring, directed toward the gate keeper residue of CDK4 (Phe93), led to significant enhancement of selectivity for CDK4 over other CDKs. Compound 3 exhibited more than 300-fold selectivity for CDK4 over CDK1, 2, 5, 7, and 9. Subsequent improvements in aqueous solubility afforded compound 4, which is available for further in vivo studies and this compound inhibited pRb phosphorylation and BrdU incorporation in tumor models.
Shimamura
Tadashi
T
Banyu Tsukuba Research Institute, Banyu Pharmaceutical Co., Ltd, 3 Okubo, Tsukuba, Ibaraki 300-2611, Japan.
Shibata
Jun
J
Kurihara
Hideki
H
Mita
Takashi
T
Otsuki
Sachie
S
Sagara
Takeshi
T
Hirai
Hiroshi
H
Iwasawa
Yoshikazu
Y