2. Academic Validation
  3. Bioactive Dimeric Tetrahydroxanthones with 2,2'- and 4,4'-Axial Linkages from the Entomopathogenic Fungus Aschersonia confluens

Bioactive Dimeric Tetrahydroxanthones with 2,2'- and 4,4'-Axial Linkages from the Entomopathogenic Fungus Aschersonia confluens

  • J Nat Prod. 2021 Apr 23;84(4):1149-1162. doi: 10.1021/acs.jnatprod.0c01212.
Karoon Sadorn 1 2,  Siriporn Saepua 3,  Nattawut Boonyuen 3 4,  Wilunda Choowong 3,  Pranee Rachtawee 3,  Pattama Pittayakhajonwut 3
Affiliations

Affiliations

  • 1 Integrated Applied Chemistry Research Unit, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok 10520, Thailand.
  • 2 Department of Chemistry, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok 10520, Thailand.
  • 3 National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Phaholyothin Road, Khlong Luang, Pathum Thani 12120, Thailand.
  • 4 National Biobank of Thailand (NBT), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Phaholyothin Road, Khlong Luang, Pathum Thani 12120, Thailand.
PMID: 33852304 DOI: 10.1021/acs.jnatprod.0c01212
Abstract

Thirteen tetrahydroxanthone dimers, atrop-ascherxanthone A (1), ascherxanthones C-G (2-6), and confluxanthones A-G (7-13), were isolated from the entomopathogenic fungus Aschersonia confluens BCC53152. The chemical structures were determined based on analysis of NMR spectroscopic and mass spectrometric data. The absolute configurations of compounds 1 and 7 were confirmed by single-crystal X-ray diffraction experiments, while the configurations of Other compounds were assigned based upon evidence from NOESY and NOEDIFF experiments, modified Mosher's method, and ECD spectroscopic data together with biogenetic considerations. Compounds 1, 3-5, 7-11, and 13 showed antimalarial activity against Plasmodium falciparum (K1, multidrug-resistant strain) (IC50 0.6-6.1 μM), antitubercular activity against Mycobacterium tuberculosis H37Ra (MIC 6.3-25.0 μg/mL), and cytotoxicity against NCI-H187 (IC50 0.5-3.5 μM) and Vero (IC50 0.9-6.1 μM) cells. All tested compounds except for compound 9 exhibited cytotoxicity against KB cells (IC50 1.3-9.7 μM).

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