Brigitte Schlegel

New and bioactive compounds from Streptomyces strains residing in the wood of Celastraceae

Abstract. Wood from three different plants of the Celastraceae growing in their natural habitats in Brazil (Maytenus aquifolia Mart.) and South Africa [Putterlickia retrospinosa van Wyk and Mostert, P. verrucosa (E. Meyer ex Sonder) Szyszyl.] was established as a source of endophytic bacteria using a medium selective for actinomycetes. Two isolates were identified as Streptomyces setonii and S. sampsonii whereas two others were not assignable to any of the known Streptomyces species. They were preliminarily named Streptomyces Q21 and Streptomyces MaB-QuH-8. The latter strain produces a new chloropyrrol and chlorinated anthracyclinone. The chloropyrrol showed high activity against a series of multiresistent bacteria and mycobacteria.

Formation of new lipoaminopeptides, acremostatins A, B, and C, by co-cultivation of Acremonium sp. Tbp-5 and Mycogone rosea DSM 12973.

Formation of new lipoaminopeptides, acremostatins A, B, and C, was observed during co-cultivation of Acremonium sp. Tbp-5 and Mycogone rosea DSM 12973. Thus, co-cultivation of microorganisms producing related products could be suggested as a suitable way towards diversification of microbial structures.

(–)‐Terpestacin and L‐tenuazonic acid, inducers of pigment and aerial mycelium formation by Fusarium culmorum JP 15

Surface cultures of Fusarium culmorum JP15 were found to respond to extracts of other fungi by enhanced production of orange‐red fusarubin pigments and formation of aerial mycelium. Two inducers from strain Ulocladium sp. HKI 0226, the new (–)‐terpestacin (1) and L‐tenuazonic acid (2), were isolated. 1 inhibited syncytium formation by cells infected with respiratory syncytial virus (RSV).

ISOLATION AND STRUCTURE OF PEPTAIBOLIN, A NEW PEPTAIBOL FROM SEPEDONIUM STRAINS

peptaibols in microbial culture extracts3~5). Here we report the isolation and structure elucidation of peptaibolin (1, Fig. 1) as an unusual representative of the peptaibol family of lipophilic antibiotics. 1 was disclosed in two fungal strains, Sepedonium sp. HKI-0117 and Sepedonium ampullosporum HKI-0053 coproducing the neuroleptic peptaibol-type antibiotic ampullosporin5). In contrast to the known peptaibols6), the compound 1 contains only five peptide bonds. However, it displays all of the structural features of the

New fasciculol-type triterpene compounds fromHypholoma fasciculare

New fasciculol‐type triterpene compounds 1, 2 and 3 were discovered in extracts of the mushroom Hypholoma fasciculare by LC‐NMR and LC‐MS methods. Isolation and structure elucidation are reported. Fasciculol and fasciculic acid production of H. fasciculare was compared with that of H. sublateritium and H. capnoides. 1 and 2 inhibited moderately 3α‐hydroxysteroid dehydrogenase (IC50: 14.0 μM).

New homoserine lipids from Xerocomus langbianensis.

New diacylglycerotrimethyl homoserine lipids 1 (2 O,3 O‐bislinolylglycero‐4′‐O‐(N,N,N‐trimethyl)homoserine) and 2 (2 O,3 O‐linolyl‐palmitylglycero‐4′‐O‐(N,N,N‐trimethyl)‐homoserine) were isolated from the fruiting body of a Vietnamese species of Xerocomus langbianensis. The chemical structures were settled on the basis of mass spectrometry and NMR spectroscopy.

Isolation and structure elucidation of new salfredin-type metabolites fromCrucibulum laeve DSM 1653 and DSM 8519

New salfredin‐type chromene and benzofurane metabolites (4—7) were isolated from submerged cultures of the fungal strains Crucibulum laeve DSM 1653 and C. laeve DSM 8519. The structures were elucidated on the basis of UV‐VIS spectroscopic, mass spectrometric and NMR spectroscopic evidence. The new metabolites are discussed as intermediates and shunt metabolites of the fungal aromatic pathway leading to A‐, B‐ and C‐type salfredins.

Ampullosporin Analogs: Solid Phase Synthesis, Conformational Studies, and Biological Activities

Ampullosporin A (Amp A) Ac-Trp-Ala-Aib-Aib-Leu-Aib-Gln-Aib-Aib-Aib-Gln-Leu-Aib-Gln-Leuol, extracted from fungus Sepedonium ampullosporum surface culture belongs to the class of peptaibols rich in Aib, with an acetylated N-terminus and an alcohol at C-terminus [1]. Besides antimicrobial effects, Amp A induces the formation of black pigment on fungus Phoma destructiva, as do cyclosporin A, chrysospermin, and also neuroleptic drugs, including haloperidol, chlorpromazine, clozapine, and sertindol. Moreover, Amp A was found to cause the hypothermia in mice suggesting a neuroleptic activity [1]. Recently, peptides containing adjacent sterically hindered Aib-residues have been synthesized without difficulties via Fmoc amino acid fluorides, which can be generated in situ by using tetramethylfluoroformamidium hexafluorophosphate (TFFH) as coupling reagent [2].