Biomedical subjects

Bärbel Köpcke

Publications and source records attributed to Bärbel Köpcke.

3 recordsLinked to original sources

PubMed2004

3-hydroxypropionic acid as a nematicidal principle in endophytic fungi.

3- Hydroxypropionic acid was isolated by bioactivity-guided fractionation of extracts obtained from submerged cultures of several endophytic fungi isolated from above-ground plant organs. This compound showed selective nematicidal activity against the plant-parasitic nematode Meloidogyne incognita with LD50 values of 12.5-15 microg/ml. Activity against the saprophytic Caenorhabditis elegans was fivefold lower. No antimicrobial, cytotoxic or phytotoxic effects were observed. Propionic acid and D- and L-lactic acids were not active against either nematode species. Based on morphological features and ITS, 18S and 28S rDNA analyses, the producing strains were identified as Phomopsis phaseoli isolated from the leaf of a tropical tree, and four strains of Melanconium betulinum isolated from twigs of Betula pendula and B. pubescens in Germany. This is the first report of 3-hydroxypropionic acid in fungi, and of the nematicidal activity of this metabolite.

Animals↗

PubMed2002

Galiellalactone and its biogenetic precursors as chemotaxonomic markers of the Sarcosomataceae (Ascomycota).

(-)-Galiellalactone is a hexaketide metabolite with interesting pharmacological activities which was detected in four strains of Galiella rufa (Sarcosomataceae, Ascomycota) and in two unidentified fungi shown by their 18S rDNA sequences also to belong to the Sarcosomataceae. These were a wood-inhabiting apothecial species from Chile and an endophytic isolate from Cistus salviifolius (Sardinia). Other members of the family (Urnula helvelloides, one Strumella coryneoidea isolate) produced no galiellalactone but merely hexaketides structurally related to galiellalactone precursors, whereas a third group of species (Sarcosoma latahensis, Strumella griseola, one S. coryneoidea isolate) lacked hexaketide production altogether. Despite thorough screening programmes, galiellalactone and its precursors have not yet been found in any fungus outside the Sarcosomataceae and may thus be a chemotaxonomic marker of the family, supporting its current phylogenetic definition. Two pentaketide derivatives of the 6-pentyl-alpha-pyrone type were found in all G. rufa strains as well as in A111-95 and the hexaketide-producing S. coryneoidea isolate.

Ascomycota↗

PubMed2002

Biologically active secondary metabolites from the ascomycete A111-95. 1. Production, isolation and biological activities.

Eight secondary metabolites were isolated from submerged cultures of the ascomycete A111-95 during a search for new nematicidal metabolites. (-)-Galiellalactone (7) and compound 2 are metabolites previously obtained from cultures of Galiella rufa while the compounds 1, 3, 4, 5, 6 and 8 (3 and 4 were obtained as an unseparable mixture), were isolated as natural products for the first time. Compound 2, pregaliellalactone (5) and the mixture of 3 and 4 showed nematicidal activities towards Caenorhabditis elegans and Meloidogyne incognita. All compounds showed moderate or weak cytotoxic activities.

Animals↗