PYRIDO[2,3-D]PYRIMIDIN-4(3 H)-ONE DERIVATIVES AND 1,2,3.4-TETRAHYDROPYRIDO[2,3-D] PYRIMIDINE-DERIVATIVES - SYNTHESIS AND IN-VITRO STUDY OF THEIR ACTIVITY AGAINST PLATELET-AGGREGATION

Some new derivatives of pyrido[2,3-d]pyrimidin-4(3 H)one A and 1,2,3,3 -tetrahydro-pyrido[2,3-d]pyrimidines B were prepared. The study of the ir in vitro antiaggregating activity showed that the compounds A posse ssed an inhibitory potency when aggregation was induced with ADP. Thei r reduction to derivatives of 1,2,3,4-tetrahydropyrido[2,3-d]pyrimidin e B led to a new series of molecules possessing a greater antiaggregat ing power. When compared to that of acetylsalicylic acid under the sam e conditions, this activity was weaker with collagen, the same with ar achidonic acid-induced aggregation, but greater when aggregation was i nduced by ADP. However, they inhibited serotonin release only slightly . Compared to ginkgolide they remained weaker with PAF-induced aggrega tion.