The synthesis of some selected PAF-acether homologues with an alkoxy-chain length from C1 to C,, in position 1 is described. All agonist activities are closely correlated among themselves and with the calculated fatty-chain hydrophobicity. After a discussion on recent published results and comparison with our data, we conclude that the ether oxide function is absolutely essential at the glycerol 1-position for potent agonist activity and that potency ...