Natural products isolation studies of native Australian fern species

Abstract

Natural products isolation studies of 16 native Australian fern species have been undertaken, facilitated by pressurised hot water extraction (PHWE). Fourteen of these fern species have not been the subject of natural products isolation research previously. In total, 14 different compounds were isolated from 12 of these 16 different fern species. This included γ- and δ-lactones; flavonoid glycosides, a dihydrobenzofuran neolignan, in addition to hydroxycinnamate/caffeic acid esters. More specifically, the lactones 5,6-dihydro-5-hydroxy-6-methyl-2H-pyran-2-one, 5-(1-hydroxyethyl)-2(5H)-furanone and osmundalin were obtained from Todea barbara, while a dihydrobenzofuran neolignan, (-)-trans-blechnic acid were found in Austroblechnum penna-marina subsp. alpina, and the shikimate ester 5-O-caffeoylshikimic acid was isolated from Parablechnum wattsii. In addition, flavonoids and their glycoside derivatives, kaempferol 3-O-glucopyranoside, 4β-carboxymethyl-(-)-epicatechin, (2R)-eriodictyol-7-O-β-d-glucopyranoside, naringin, quercitrin, quercetin 3-O-(6″-acetyl)-β-d-glucopyranoside, rutin, and tiliroside were isolated from seven other fern species.