Antiplatelets activity of some xanthone derivatives

The effects of twelve aminoalkanolic derivatives of xanthone on platelet aggregation have been evaluated. Five from them inhibited thrombin-induced platelet aggregation. The most active compound was R-(+)-2-N-(7-chloro-2-xanthonemethyl)-2-N-methylamino-1-butanol [IV] which, at a concentration of 40 micrograms/ml, nearly completely inhibited the aggregation concentration (TAC) of thrombin.