Lignans from Linum species of sections Syllinum and Linum.

The aryltetralin lignans 6-methoxypodophyllotoxin, 5'-demethoxy-6-methoxypodophyllotoxin as well as the corresponding 8'-epimers 6-methoxypicropodophyllin, and 5'-demethoxy-6-methoxypicropodophyllin were isolated from suspension cultures of Linum cariense, and 4'-demethyl-6-methoxypodophyllotoxin together with 6-methoxypodophyllotoxin from plants of L. tauricum, which both belong to section Syllinum of the genus Linum. Cell cultures of L. altaicum, L. austriacum ssp. euxinum and L. lewisii belonging to section Linum accumulate the naphthalene lignans justicidin B and isojusticidin B. The different lignans were identified by HPLC and spectroscopic methods.