In the course of our exploration of the Thai invertebrate-pathogenic fungi for biologically active metabolites, pigmentosin A (1) and a new bis(naphtho-α-pyrone) derivative, pigmentosin B (2), were isolated from the spider-associated fungus Gibellula sp. Furthermore, a new glycosylated asperfuran 3, together with one new (6) and two known (4 and 5) cyclodepsipeptides, was isolated from Cordyceps javanica. The pigmentosins 1 and 2 showed to be active against biofilm formation of Staphylococcus aureus DSM1104. The lack of toxicity toward the studied microorganism and cell lines of pigmentosin B (2), as well as the antimicrobial effect of pigmentosin A (1), made them good candidates for further development for use in combination therapy of infections involving biofilm-forming S. aureus. The structure elucidation and determination of the absolute configuration were accomplished using a combination of spectroscopy, including 1D and 2D NMR, HRMS, Mosher ester analysis, and comparison of calculated/experimental ECD spectra. A chemotaxonomic investigation of the secondary metabolite profiles using analytical HPLC coupled with diode array detection and mass spectrometry (HPLC-DAD-MS) revealed that the production of pigmentosin B (2) was apparently specific for Gibellula sp., while the glycoasperfuran 3 was specific for C. javanica.
natural products, antibiofilm agents, spider-parasitic fungi
NCBI PubMed ID: 31921369Publication DOI: 10.3762/bjoc.15.293Journal NLM ID: 101250746Publisher: Beilstein-Institut
Correspondence: marc.stadler@helmholtz-hzi.de
Institutions: Department of Chemistry, Faculty of Science, Aswan University, Aswan, Egypt, Department of Microbiology, Faculty of Science, Prince of Songkla University, Songkhla, Thailand, Department of Chemistry, Faculty of Science, Prince of Songkla University, Songkhla, Thailand, Microbial Drugs, Helmholtz Centre for Infection Research GmbH (HZI), Braunschweig, Germany, Faculty of Science and Technology, Prince of Naradhiwas University, Narathiwat, Thailand, Computational Chemistry Laboratory, Chemistry Department, Faculty of Science, Minia University, Minia, Egypt, National Centre for Genetic Engineering and Biotechnology (BIOTEC), NSTDA, Pathum Thani, Thailand
Methods: 13C NMR, 1H NMR, NMR-2D, acid hydrolysis, HPLC, extraction, optical rotation measurement, CD, LC-MS, cell growth, HPLC-MS, HR-ESI-MS, cytotoxicity assay, derivatization, antimicrobial assay
Found