Klaus-Peter Adam

Biosynthesis of the isoprene units of chamomile sesquiterpenes

Abstract Chamomile sesquiterpenes were labelled with 13 C by injection of an [1- 13 C]glucose solution into the anthodia of the plant. The sesquiterpenes bisabololoxide A and chamazulene were isolated from the hydrodistillate of the labelled flowers. Analysis of the labelling patterns and absolute 13 C abundances using quantitative 13 C NMR spectroscopy showed that two of the isoprene building blocks were predominantly formed via the new triose\pyruvate pathway, whereas the third unit was of mixed origin, being derived from both the mevalonic acid pathway and the triose\pyruvate pathway.

Biosynthesis of the sesquiterpene germacrene D in Solidago canadensis: 13C and 2H labeling studies

The biogenetic origin of the isoprenoid building blocks of the sesquiterpene germacrene D was studied in Solidago canadensis. Feeding experiments were carried out with 1-[5,5-D(2)]deoxy-D-xylulose-5-phosphate (D(2)-DOXP), [5-13C]mevalonolactone (13C-MVL) and [1-13C]-D-glucose. The hydrodistillate of a cut shoot fed with D(2)-DOXP was investigated by enantio-MDGC-MS and the volatile fraction of a shoot supplied with 13C-MVL was examined by GC-C-IRMS. The incorporation of [1-13C]-D-glucose was analyzed by quantitative 13C NMR spectroscopy after isolation of germacrene D from the essential oil. Our labeling studies revealed that the biosynthesis of the C-15 skeleton of sesquiterpene germacrene D in Solidago canadensis proceeds predominantly via the methylerythritol phosphate pathway.

Bisbibenzyls and lignans from Pellia epiphylla

Abstract Three new bisbibenzyls, 14-hydroxyperrottetin E, 14′-hydroxyperrottetin E and 14,14′-dihydroxyperrottetin E, and three new lignans, 2,3-dicarboxy-6

Five lignan derivatives from in vitro cultures of the liverwort Jamesoniella autumnalis

Abstract Five new lignan derivatives, 2,3,6′-tricarboxy-6,7-dihydroxy-1(3′)-2′-pyranonyl-1,2-dihydronaphthalene, its two monomethyl esters, 2,6′-dicarboxy-6,7-dihydroxy-1(3′)-2′-pyranonyl-1,2-dihydronaphthalene and 2,3-dicarboxy-6,7-dihydroxy-1-(3′,4′-dihydroxy)-phenylnaphthalene, were isolated from the methanolic extract of aseptic cultures of the liverwort Jamesoniella autumnalis . Their structures were determined by spectroscopic analysis.

Sesquiterpene lactones and bisbibenzyl derivatives from the neotropical liverwort Frullania convoluta

Abstract The new germacranolide epi -isocostunolide and two new bisbibenzyls, 2′-(11-hydroxy-1-bibenzyl-oxy)-1′-methoxy-6′,10′,11′-trihydroxy-7′,8′-dihydro-phenanthrene and 2′-(10,11-dihydroxy-1-bibenzyl-oxy)-1′-methoxy-6′,10′,11′-trihydroxy-7′,8′-dihydrophenanthrene, along with the known eudesmanolides, α-cyclocostunolide, brothenolide, nepalensolide A and nepalensolide B, the bisbibenzyls, perrottetin E, perrottetin F, perrottetin G, 7′,8′-dehydroperrottetin F, and the bibenzyls, lunularic acid and lunularin, have been isolated from the neotropical liverwort Frullania convoluta . Their structures were elucidated by NMR spectroscopy.

Phenolic constituents of the fern Phegopteris connectilis

Abstract The new compounds 2,4,6-trihydroxybenzoic acid-4-O-2′,3′,4′,6′-tetraacetylglucoside, 2,4,6-trihydroxybenzoic acid-4-O-2′,3′,6′-triacetylglucoside and 2,4,6-trihydroxybenzoic acid-4-O-3′,4′,6′-triacetylglucoside, 3-O-p-coumaroylshikimic acid and 2-(trans-1,4-dihydroxy-2-cyclohexenyl)-5-hydroxy-7-methoxychromone were isolated from the methanolic extract of fronds of Phegopteris connectilis, along with kaempferol and kaempferol-3-O-β- d -glucoside. Their structures have been elucidated by spectroscopic analysis.

Pinguisane sesquiterpenes from the liverwort porella Navicularis

Abstract Four new pinguisanes, 5-pinguisen-11-ol, 6 α -methoxy-pinguis-5(10)-en-11,6-olide, 6 α -methoxy-pinguis-5(10)-en-11,6-olide-15-carboxylic acid and 5 α ,10 α -epoxy-pinguisane-11,6-olide-15-carboxylic acid methyl ester, have been isolated from the North American liverwort Porella navicularis along with two known pinguisane-type sesquiterpenes, the drimane albicanol, allo -cedrol and the known diterpenes naviculide and trans -communic acid. The structures were elucidated by spectroscopic methods. Furthermore, sesquiterpene and diterpene hydrocarbons were identified by GC-MS analysis.

Pelliatin, a macrocyclic lignan derivative from Pellia epiphylla☆

Abstract A new macrocycle consisting of a lignan, caffeic acid and an aliphatic C 8 moiety has been isolated from the liverwort, Pellia epiphylla . Its structure has been elucidated based on extensive NMR spectral evidence and by chemical derivatization. A possible biosynthetic pathway for the C 8 moiety is discussed.

Lipophilic flavonoids from the fern Woodsia scopulina

Abstract Two new flavones with a hydroxymethyl substitution in the B-ring, 8,10-dihydroxy-5- H -isochromeno[4,3- b ]chromen-7-one and 8,10-dihydroxy-11-methoxy-5- H -isochromeno[4,3- b ]chromen-7-one and ten B-ring non-substituted dihydrochalcones, chalcones, flavonols including two new flavanonol stereoisomers, cis -3-acetoxy-5,7-dihydroxyflavanone and cis -3-hydroxy-5,7-dimethoxyflavanone, have been isolated from the dichloromethane extract of fronds of the North American fern Woodsia scopulina . Furthermore, two humulanetype sesquiterpenes, humulene-6,7-epoxide and the new compound 6,7-epoxy-5-hydroxyhumula-2,9-diene, were obtained from this plant. Their structures have been identified by spectroscopic analysis.

Caffeic acid derivatives in fronds of the lady fern (Athyrium filix-femina)

Abstract A new caffeic acid amide, N -caffeoyl-phenylalanine, has been isolated from fronds of Athyrium filix-femina along with the known compounds N -caffeoyl-tryptophan, 5- O -caffeoyl-shikimic acid, 3,4-di- O -caffeoyl-quinic acid and chlorogenic acid. Their structures have been identified by spectroscopic analysis.