<i>cis</i> -Decalinoyltetramic Acid Derivatives from the Palm Fungus <i>Leptosporella arengae</i> TBRC-BCC32590

Twelve hitherto undescribed <i>cis</i>-decalinoyltetramic acid derivatives (arengasetins A - L), a unique spiro[2.4]heptendione (spiroarengarone) and two benzoquinones (arengaquinones A and B), together with the highly oxygenated polycyclic molecule, epicolactone, were isolated from the palm fungus <i>Leptosporella arengae</i> TBRC-BCC 32590. Chemical structures were determined by extensive analyses of 2D NMR spectroscopic data and chemical means. The absolute configuration of arengasetin A (<b>1</b>) was confirmed by X-ray crystallographic information, while the absolute configurations of other related compounds were corroborated by comparison of NMR spectroscopic data and chemical reactions. The isolated compounds exhibited activity against <i>Plasmodium falciparum</i> (K1, multidrug-resistant strain, IC₅₀ 6.42 - > 38.76 μM), <i>Bacillus cereus</i> (MIC 0.78 - > 50.0 μg/mL), <i>Staphylococcus aureus</i> (MIC 1.56 - > 50.0 μg/mL), and <i>Mycobacterium tuberculosis</i> (MIC 6.25 - > 50.0 μg/mL). Cytotoxicity against both cancerous (MCF-7 and NCI-H187) and noncancerous (Vero) was also reported.