Sparticolins A-G, Biologically Active Oxidized Spirodioxynaphthalene Derivatives from the Ascomycete  Sparticola junci .
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.
Phukhamsakda C, Macabeo APG, Huch V, Cheng T, Hyde KD, Stadler M