title: Changes in secondary metabolism during stromatal ontogeny of Hypoxylon fragiforme.
abstract: Stromata of Hypoxylon fragiforme were studied during the vegetation period by hplc profiling, revealing changes in the composition during stromatal development. Cytochalasin H and two new cytochalasins named fragiformins A-B were identified as major constituents of the young, maturing stromata, whereas mature, ascogenous material yielded large amounts of mitorubrin-type azaphilones. The above compounds, further cytochalasins from Xylariaceae and other fungi, and additional azaphilones of the mitorubrin type were assayed for their nematicidal effects against Caenorhabditis elegans and their antimicrobial activities against Bacillus subtilis, Yarrowia lipolytica, and various filamentous fungi. The results confirmed data in the literature on broad-spectrum non-selective activities of azaphilones and cytochalasins in biological systems. Most interestingly, laboratory cultures of the above Hypoxylon spp. mainly produced dihydroisocoumarin derivatives and were found devoid of mitorubrins and cytochalasins. These rather drastic changes in the secondary metabolism of H. fragiforme and the above biological activities are discussed in relation to the possible biological functions of secondary metabolites (extrolites) in the Hypoxyloideae.
authors.affiliation: Intermed Discovery GmbH, BioMedizin Zentrum Dortmund, Otto-Hahn-Str. 15, D-44227 Dortmund, Germany. marc.stadler@t-online.de
authors.forename: Marc
authors.initials: M
authors.lastname: Stadler
authors.forename: Dang Ngoc
authors.initials: DN
authors.lastname: Quang
authors.forename: Ayumi
authors.initials: A
authors.lastname: Tomita
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Asakawa
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000969:Antinematodal Agents / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D001578:Benzopyrans / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D017173:Caenorhabditis elegans / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D003572:Cytochalasins / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D005658:Fungi / Q000187:drug effects; D007928:Lethal Dose 50; D008826:Microbial Sensitivity Tests; D010860:Pigments, Biological / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013098:Xylariales / Q000737:chemistry / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000890:Anti-Infective Agents; D000969:Antinematodal Agents; D001578:Benzopyrans; D003572:Cytochalasins; D010860:Pigments, Biological; C494154:azaphilone