New cytotoxic constituents from the Red Sea soft coral <i>Nephthea</i> sp.

<p><i>Nephthea</i> are soft coral species rich in sesquiterpenoids and steroids. An organic extract of <i>Nephthea</i> sp. resulted in the isolation of a new steroid (<b>1</b>), as well as several previously reported metabolites (<b>2</b>–<b>9</b>). Structures were elucidated by employing NMR and HR-EI-MS analyses. The total extract, fractions and purified compounds exhibited differential cytotoxicity against the breast cancer MCF-7 cell line.