<p>Two new benzaldehyde derivatives, named 3′-OH-tetrahydroauroglaucin (<b>1</b>) and(3′<i>S</i>*,4′<i>R</i>*)-6-(3′,5-epoxy-4′-hydroxy-1′-heptenyl)-2-hydroxy-3-(3′′-methyl-2′′-butenyl)benzaldehyde (<b>2</b>), were isolated from a gorgonian-derived <i>Eurotium</i> sp. fungus. Their structures were determined by extensive spectroscopic analysis including NMR and MS spectra. Dissolved <b>1</b> in CDCl<sub>3</sub> for several days could be detected its 2<i>H</i>-chromene skeleton derivatives (<b>1a</b>/<b>1b</b>), a pair of enantiomers with opposite configurations at C-3′. Compound <b>2</b> was also found to chemically convert to a pair of epimers non-enzymatically. The plausible mechanism to form the 2<i>H</i>-chromene artefacts with racemisation at C-3′ undergoing nucleophilic substitution (S<sub>N</sub>1) was proposed.</p
