Killarniensolide, methyl orsellinates and 9,10-dihydrophenanthrenes from the liverwort Plagiochila killarniensis from Scotland and the Azores

Abstract

Methyl everninate has been identified as the major constituent of the deuterochloroform extract of ten specimens of the liverwort Plagiochila killarniensis. Using NMR fingerprinting and GC-MS, the new methyl 6-hydroxy- 2-methyl-3,4-methylenedioxybenzoate and three other methyl orsellinate derivatives were identified as minor components. 9,10-Dihydro-3,5- dimethoxyphenanthren-2-ol and 9,10-dihydro-3-methoxyphenanthrene-4,5-diol, previously reported from a Neotropical Plagiochila, were also present. Killarniensolide, a new phthalide, was isolated; its structure was elucidated as 3-(2-hydroxy-4,5-dimethoxybenzyl)-7-methoxyphthalide by NMR spectroscopy, GC-MS and isolation of an acetate derivative. Chemical differences between specimens from Scotland and the Azores were relatively minor but characteristic; small differences between some of the Scottish materials were also observed.