Leualacin (1), a cyclic depsi-pentapeptide, and its backbone/amide-modified
analogs 2-4 were synthesized. Amide analogue 3 exhibited stronger vasodila
tory effects. It also strongly inhibited collagen- and arachidonic acid (AA
)induced platelet aggregations with IC(50)s of 0.6 mu M and 2.0 mu M, respe
ctively (C) 1999 Elsevier Science Ltd. All rights reserved.