Sparticolins A-G, Biologically Active Oxidized Spirodioxynaphthalene Derivatives from the Ascomycete Sparticola junci

  • J Nat Prod. 2019 Oct 25;82(10):2878-2885. doi: 10.1021/acs.jnatprod.9b00604.
Chayanard Phukhamsakda  1 ,  Allan Patrick G Macabeo  2  3 ,  Volker Huch  4 ,  Tian Cheng  2 ,  Kevin D Hyde  1 ,  Marc Stadler  2
Affiliations
  • 1. Center of Excellence in Fungal Research , Mae Fah Luang University , Chiang Rai 57100 , Thailand.
  • 2. Department of Microbial Drugs , Helmholtz Centre for Infection Research and German Centre for Infection Research (DZIF) , partner site Hannover/Braunschweig, Inhoffenstrasse 7 , 38124 Braunschweig , Germany.
  • 3. Laboratory for Organic Reactivity, Discovery and Synthesis (LORDS), Research Center for the Natural and Applied Sciences , University of Santo Tomas , 1015 Manila , Philippines.
  • 4. Institut für Anorganische Chemie , Universität des Saarlandes , Campus, Gebäude C 4.1, 66123 Saarbrücken , Germany.
PMID: 31599583 DOI: 10.1021/acs.jnatprod.9b00604
Abstract

To explore the chemical diversity of metabolites from new species of Dothideomycetes, the ex-type strain of Sparticola junci was investigated. Seven highly oxygenated and functionalized spirodioxynaphthalene natural products incorporating carboxyalkylidene-cyclopentanoid (1-4), carboxyl-functionalized oxabicyclo[3.3.0]octane (5-6), and annelated 2-cyclopentenone/δ-lactone (7) units, sparticolins A-G, were isolated from submerged cultures of the fungus. Their chemical structures including their relative (and absolute) configurations were established through spectroscopic and X-ray crystallographic analyses. Sparticolin B (2) exhibited inhibitory activity against the Gram-positive bacteria Bacillus subtilis, Micrococcus luteus, and Staphylococcus aureus, while sparticolin G (7) showed Antifungal activities against Schizosaccharomyces pombe and Mucor hiemalis. All Other sparticolins were only weakly active against S. aureus and also showed weak activities against the nematode Caenorhabditis elegans. Compounds 2 and 7 also showed moderate cytotoxic activities against seven mammalian cell lines.