Cultivation of Cordyceps indigotica, an entomopathogenic fungus, in the presence of suberoyl bis-hydroxamic acid (an HDAC inhibitor) greatly activated its polyketide synthesis apparatus to afford six novel aromatic polyketides, indigotides C-F (1-4), 13-hydroxyindigotide A (5), and 8-O-methylindigotide B (6). The structures of these compounds were determined by NMR spectroscopic analyses. Among the compounds, indigotides C-E (1-3) possessed unprecedented dimeric polyketide frameworks possibly generated via a [4 + 2] cycloaddition or Michael type reaction.
polyketide, Cordyceps, histone deacetylase inhibitor, hydroxamic acid, suberoyl bis-hydroxamic acid
NCBI PubMed ID: 22480311Publication DOI: 10.1021/ol3005062Journal NLM ID: 100890393Publisher: American Chemical Society
Correspondence: tasai@m.tohoku.ac.jp
Institutions: Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
Methods: 13C NMR, 1H NMR, IR, DNA techniques, TLC, acid hydrolysis, MS, HPLC, UV, extraction, optical rotation measurement, CD, CC, cell growth, COSY, HR-EI-MS