Five new lignan derivatives, hydroxy-1(3')-2'-pyranonyl-1,2-dihydronap
hthalene, its two monomethyl esters, 2,6'-dicarboxy-6,7-dihydroxy-1 (3
')-2'-pyranonyl-1,2-dihydronaphthalene and 7-dihydroxy-1-(3',4'-dihydr
oxy)-phenylnaphthalene, were isolated from the methanolic extract of a
septic cultures of the liverwort Jamesoniella autumnalis. Their struct
ures were determined by spectroscopic analysis.