PAF-antagonistic bicyclo[3.2.1]octanoid neolignans from leaves of Ocotea macrophylla Kunth. (Lauraceae)

Di-nor-benzofuran neolignan aldehydes, (ocophyllal A-B) 1-2, and macrophyllin-type bicyclo[3.2.1]octanoid neolignans (ocophyllol A-C) 3-5, as well as 2′-epi-guianin 6 and (+)-licarin B 7, were isolated from leaves of Ocotea macrophylla. Their structures and absolute configurations were determined by spectroscopic analyses. Inhibition of platelet activating factor (PAF)-induced aggregation of rabbit platelets were tested with neolignans 1-7. Although compound 6 was the most potent PAF-antagonist, compounds 3-5 showed some activity.