(Sp)-octyl-8-chloroadenosine 3', 5'-cyclophosphate inhibited the growth of tumor cells by regulating cell signaling pathways. Its metabolic compound, 8-Cl-adenosine, also demonstrated the behaviors of inducing differentiation and initiating apoptosis in some tumor cells. Starting from D(L)-xylose, D-glucose, or 2-amino-2-deoxy-D- glucose, five types of isonucleosides were synthesized. The oligonucleotides containing isonucleosides showed remarkable stability to the degradation by phosphodiesterase and their capacities of hybridizing complementary sequence depended on the structure of the isonucleosides and the linkage mode of the phosphodiester.

Key words: ADENOSINE, ADENOSINE 3'5' CYCLIC PHOSPHATE, TARGETS, OLIGONUCLEOTIDE, ENDOGENOUS, BIOACTIVE SUBSTANCE