Antibacterial Neurymenolides from the Fijian Red Alga <i>Neurymenia fraxinifolia</i>

Two novel α-pyrone macrolides, neurymenolides A (&lt;b&gt;1&lt;/b&gt;) and B (&lt;b&gt;2&lt;/b&gt;), were isolated from the Fijian red alga &lt;i&gt;Neurymenia fraxinifolia&lt;/i&gt; and characterized using a combination of NMR and mass spectral analyses. These molecules represent only the second example of α-pyrone macrolides, with &lt;b&gt;1&lt;/b&gt; existing as interchanging atropisomers due to restricted rotation about the α-pyrone ring system. Neurymenolide A (&lt;b&gt;1&lt;/b&gt;) displayed moderately potent activities against methicillin-resistant &lt;i&gt;Staphylococcus aureus&lt;/i&gt; (MRSA) and vancomycin-resistant &lt;i&gt;Enterococcus faecium&lt;/i&gt; (VREF).