Structure-based design approach was successfully used to guide the evolution of imidazopyridine scaffold yielding new structural class of highly selective inhibitors of cyclin dependent kinases that were able to form a new interaction with an identified residue of the protein, Lys89. Compounds from this series have shown no detectable effect when tested against a representative set of other serine/threonine kinases such as GSK3beta, CAMKII, PKA, PKC-alpha,beta,epsilon,gamma. Compound 2i inhibits proliferation in HCT 116 cells in tissue culture.
View Article and Find Full Text PDFWe have identified a novel structural class of protein serine/threonine kinase inhibitors comprised of an aminoimidazo[1,2-a]pyridine nucleus. Compounds from this family are shown to potently inhibit cyclin-dependent kinases by competing with ATP for binding to a catalytic subunit of the protein. Structure-based design approach was used to direct this chemical scaffold toward generating potent and selective CDK2 inhibitors.
View Article and Find Full Text PDFThe synthesis of novel aza-1,7-annulated indoles was achieved and these were converted to indolocarbazoles that proved to be potent kinase inhibitors. These compounds were also evaluated in a human colon carcinoma cell line and proved to be good antiproliferative agents.
View Article and Find Full Text PDFThe synthesis and kinase inhibitory activity of a series of novel 1,7-annulated indolocarbazoles 6 and 16 is described. These compounds exhibited potent inhibitory activity against cyclin-dependent kinase 4 and good antiproliferative activity in a human colon carcinoma cell line.
View Article and Find Full Text PDFThe synthesis of a novel series of 1,7-annulated indolocarbazoles 2 and 16 is described. These compounds were found to be potent cyclin dependent kinase inhibitors with good antiproliferative activity against two human carcinoma cell lines. These inhibitors also arrested tumor cells at the G1 phase and inhibited pRb phosphorylation.
View Article and Find Full Text PDFThe protein kinase family represents an enormous opportunity for drug development. However, the current limitation in structural diversity of kinase inhibitors has complicated efforts to identify effective treatments of diseases that involve protein kinase signaling pathways. We have identified a new structural class of protein serine/threonine kinase inhibitors comprising an aminoimidazo[1,2-a]pyridine nucleus.
View Article and Find Full Text PDFA series of indolo[2,3-a]pyrrolo[3,4-c]carbazoles and their bis-indolylmaleimides precursors have been prepared in order to compare their activity as D1-CDK4 inhibitors. Both enzymatic and antiproliferative assays have shown that the structurally more constrained indolo[2,3-a]pyrrolo[3,4-c]carbazoles are consistently more active (8-42-fold) in head-to-head comparison with their bis-indolylmaleimides counterparts. Cell-cycle analysis using flow cytometry have also shown that the indolocarbazoles are selective G1 blockers while the bis-indolylmaleimides arrest cells in the G2/M phase.
View Article and Find Full Text PDFBioorg Med Chem Lett
November 2003
The synthesis of new analogues of Arcyriaflavin A in which one indole ring is replaced by an aryl or heteroaryl ring is described. These new series of aryl[a]pyrrolo[3,4-c]carbazoles were evaluated as inhibitors of Cyclin D1-CDK4. A potent and selective D1-CDK4 inhibitor, 7a (D1-CDK4 IC(50)=45 nM), has been identified.
View Article and Find Full Text PDFThe synthesis and CDK inhibitory properties of a series of indolo[6,7-a]pyrrolo[3,4-c]carbazoles is reported. In addition to their potent CDK activity, the compounds display antiproliferative activity against two human cancer cell lines. These inhibitors also effect strong G1 arrest in these cell lines and inhibit Rb phosphorylation at Ser780 consistent with inhibition of cyclin D1/CDK4.
View Article and Find Full Text PDFNovel substituted indolocarbazoles were synthesized, and their kinase inhibitory capability was evaluated in vitro. 6-Substituted indolocarbazoles 4 were found to be potent and selective D1/CDK4 inhibitors. 4d and 4h exhibited potent and ATP-competitive D1/CDK4 activities with IC50 values of 76 and 42 nM, respectively.
View Article and Find Full Text PDFA novel series of pyrrolo[3,4-c] carbazoles fused with a quinolinyl/isoquinolinyl moiety were synthesized and their D1/CDK4 inhibitory and antiproliferative activity were evaluated. Compound 8H, 14H-isoquinolinyl[6,5-a]-pyrrolo[3,4-c]carbazole-7,9-dione (1d) was found to be a highly potent D1/CDK4 inhibitor with an IC(50) of 69 nM. Compound 1d also inhibited tumor cell growth, arrested tumor cells in G1 phase and inhibited pRb phosphorylation.
View Article and Find Full Text PDF