A SIMPLE METHOD FOR SYNTHESIS OF SPONGOSINE, AZASPONGOSINE, AND THEIRANTIPLATELET EFFECTS

Reaction of 2-ethylthioadenine (1) with protected ribose (2) in the pr esence of stannic chloride gave 2-ethylthioadenosine (4). Oxidation of 5 with potassium permanganate yielded the corresponding sulfone (6) w hich furnished spongosine (2) after treatment with sodium methoxide. S imilarly, reactions of -amino-5-ethylthio-1,2,3-triazolo[4,5-d]pyrimid ine (8) with the ribose (2) gave 8-azaspongosine (13). The compounds ( 4) and 2 demonstrated potent antiaggregatory effects both in human pla telet-rich plasma and whole blood, whereas, the aza analog (13) showed no inhibitory activity on platelet aggregation. Both (4) and (7) inhi bit platelet aggregation in the presence of adenosine deaminase, where as, adenosine is non-inhibitory, suggesting that analogs (4) and (7) a re poor substrates for adenosine deaminase.