Abstract
Four new lignans, (+)-1-acetoxypinoresinol [(1S, 2R, 5R, 6S)-1-acetoxy-2, 6-bis (4-hydroxy-3-methoxyphenyl)-3, 7-dioxabicyclo [3. 3. 0] octane] (1), (+)-1-hydroxypinoresinol (2), (+)-1-acetoxypinoresinol 4"-O-methyl ether (3) and (+)-1-hydroxypinoresinol 4"-O-methyl ether (4), and two known lignans, (-)-olivil (5) and (+)-cyclo-olivil (6), were isolated from the bark of Olea europaea L. (Oleaceae). Their structures were elucidated on the basis of spectroscopic analysis and chemical evidence. The lignans 1, 2 and 3 were also isolated from the bark of Olea africana MILL. (Olea europaea L. subsp. africana (MILL.) GREEN), and lignans 5 and 6 from the bark of Olea capensis L.
