Study on the Synthesis and PKA-I Binding Activities of 5-Alkynyl Tubercidin Analogues Original Research Article

5-Alkynyl tubercidin analogues were synthesized and their biological activities were evaluated. It was found that protein kinase A could be activated by 5-alkynyl tubercidin (9a) and cAMP-binding ability to PKA-I was selectively inhibited by it. Molecular modeling showed that the interaction of 9a and PKA-I was associated with the existence of hydrophobic alkynyl group. During the synthesis of tubercidin analogues, a pair of 2′-carbonyl participating abnormal coupling products (11a, 11b) was obtained, the structure was identified by X-ray crystalline diffraction.