Hassallidin A (1), a new antifungal glycosylated lipopeptide, was isolated from an epilithic cyanobacterium collected in Bellano, Italy, identified as Tolypothrix (basionym Hassallia) species. Chemical, mass spectrometric, and spectroscopic analyses, including one- and two-dimensional NMR, were performed to determine an esterified eight-residue cyclic peptide linked with a carbohydrate and a fatty acid residue. Chiral GC-MS analysis revealed the occurrence of the nonproteinogenic amino acids D-allo-Thr, D-Thr, D-Tyr, D-Gln, and dehydroaminobutyric acid (Dhb) within the peptide moiety. The additional components of hassallidin A could be identified as alpha,beta-dihydroxytetradecanoic acid (Dht) and mannose. This is the first report on a cyclic peptide of cyanobacterial origin that contains both a fatty acid and a carbohydrate moiety. Compound 1 exhibits antifungal activity against Aspergillus fumigatus and Candida albicans with MIC values of 4.8 μg/mL for both test organisms
hassalidin A, antifungal activity, Tolypothrix, cyclic peptide
NCBI PubMed ID: 15921412Publication DOI: 10.1021/np049671rJournal NLM ID: 7906882Publisher: American Society of Pharmacognosy
Correspondence: doehren@chem.tu-berlin.de
Institutions: Institut für Chemie, Fak. II, Technische Universität Berlin, Berlin, Germany, Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany, Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Humboldt-Universität, Berlin, Germany, Zentrum für Biophysik und Bioinformatik, Humboldt-Universität, Berlin, Germany
Methods: 13C NMR, 1H NMR, NMR-2D, IR, GC-MS, ESI-MS, acid hydrolysis, ESI-ICR-MS, amino acid analysis, MALDI-TOF MS, HPLC, UV, extraction, 15N NMR, cell growth, derivatization, evaporation, centrifugation, antifungal activity test, optical density measurement
Found