Sporothriolide derivatives as chemotaxonomic markers forHypoxylon monticulosum.
During the course of a screening for novel anti-infective agents from cultures of tropical Xylariaceae originating from French Guiana and Thailand, pronounced antifungal activity was noted in extracts of cultures ofHypoxylon monticulosum. A bioassay-guided fractionation led to the known metabolite sporothriolide as active principle. In addition, three new derivatives of sporothriolide were isolated, for which we propose the trivial names sporothric acid, isosporothric acid and dihydroisosporothric acid. Their chemical structures were elucidated by high-resolution electrospray mass spectrometry in conjunction with two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy. From earlier studies on the biogenesis of the chemically similar canadensolides, we postulate that the new compounds were shunt products, rather than biogenetic precursors of sporothriolide. Interestingly, this compound class, as well as strong antifungal activities, was only observed in multiple cultures ofH. monticulosum, but not in several hundreds ofHypoxyloncultures studied previously or concurrently. Therefore, sporothriolide production may constitute a species-specific feature with respect toHypoxylonand theXylariaceae, although the compound was previously reported from non-related fungal taxa.
Department Microbial Drugs, Helmholtz-Centre for Infection Research , Inhoffenstrasse 7, 38124 Braunschweig , Germany ; German Centre for Infection Research (DZIF) , Inhoffenstraße 7, 38124 Braunschweig , Germany.
Frank
F
Surup
Department Microbial Drugs, Helmholtz-Centre for Infection Research , Inhoffenstrasse 7, 38124 Braunschweig , Germany ; German Centre for Infection Research (DZIF) , Inhoffenstraße 7, 38124 Braunschweig , Germany.
Eric
E
Kuhnert
Department Microbial Drugs, Helmholtz-Centre for Infection Research , Inhoffenstrasse 7, 38124 Braunschweig , Germany ; German Centre for Infection Research (DZIF) , Inhoffenstraße 7, 38124 Braunschweig , Germany.
Erik
E
Lehmann
Department Microbial Drugs, Helmholtz-Centre for Infection Research , Inhoffenstrasse 7, 38124 Braunschweig , Germany ; German Centre for Infection Research (DZIF) , Inhoffenstraße 7, 38124 Braunschweig , Germany.
Simone
S
Heitkämper
Institute of Excellence in Fungal Research and School of Science, Mae Fah Luang University , Chiang Rai 57100 , Thailand.
Kevin D
KD
Hyde
Las Muros , F-09420 Rimont , France.
Jacques
J
Fournier
Department Microbial Drugs, Helmholtz-Centre for Infection Research , Inhoffenstrasse 7, 38124 Braunschweig , Germany ; German Centre for Infection Research (DZIF) , Inhoffenstraße 7, 38124 Braunschweig , Germany.
Marc
M
Stadler
Hypoxylon; antibiotics; chemotaxonomy; furofurandiones; screening; secondary metabolites