Duclauxamide
A1 (<b>1</b>), a new polyketide-derived heptacyclic
oligophenalenone dimer with a <i>N</i>-2-hydroxyethyl moiety,
was isolated from <i>Penicillium manginii</i> YIM PH30375.
Spectroscopic analysis, X-ray single crystal diffraction, and <sup>13</sup>C NMR DFT calculations confirmed that compound <b>1</b> and other duclauxin analogues possess the unified <i>S</i> configuration at C-9′, which corrects a long-standing misrepresentation
of duclauxins as C-9′<i>R</i> epimers. A plausible
biosynthetic pathway for duclauxins is proposed on the basis of previous
acetate labeling results for duclauxin and sclerodin