Synthesis of echiguanine analogs and their ribofuranosyl glycosides that inhibit phosphatidylinositol 4-kinase

N-carboxamide-substituted 7-deazaguanine-7-carboxamides and their ribofuranosyl compounds have been synthesized as echiguanine derivatives, and evaluated for inhibition of phosphatidylinositol (PI) 4-kinase. The ethylamide derivative and the corresponding ribofuranosyl compound inhibited PI 4-kinase with IC50 values of 0.02 and 2.4 μg/ml, respectively. The latter was suggested to also inhibit the enzyme in cultured human epidermoid carcinoma cells.