TABLE 3

Summary of the modifications in the oxazaborolidine or oxazolidine ring (Fig. 9) that influence the ability of thrombin to stimulate Ca²⁺ influx in human platelets The introduction of carbonyl groups or oxygen into the five-membered ring tends to decrease activity. The introduction of a benzyl on carbon 4 increased activity of the parent 2-APB molecule. There were many modifications and substitutions on the ring that could be tolerated and which had minimal effect on activity.