Minor and Trace Sterols in Marine Invertebrates. 26. Isolation and Structure Elucidation of Nine New 5α,8α-Epidioxy Sterols from Four Marine Organisms

Article abstract of DOI:10.1021/jo00332a020

Sixteen 5α,8α-epidioxy Δ⁶ and Δ^6,9(11) sterols, of which nine are new, have been isolated from the marine organisms Ascidia nigra, Dendrogyra cylindrus, Thalysias juniperina, and Aplysia dactylomela by reverse-phase high-performance liquid chromatography and characterized by high-resolution mass spectrometry and 360-MHz proton NMR spectroscopy.Attention is drawn to some unusual concentration-dependent NMR shifts of methyl signals.The probable biological significance of these epidioxy sterols is discussed with special reference to sterol biosynthesis.