Identification of a novel alkenone in Black Sea sediments

TitleIdentification of a novel alkenone in Black Sea sediments
Publication TypeJournal Article
Year of Publication2000
AuthorsXu, L, Reddy, CM, Farrington, JW, Frysinger, GS, Gaines, RB, Johnson, CG, Nelson, RK, Eglinton, TI
JournalOrganic Geochemistry
KeywordsAlkenone, Black Sea, Haptophytes, Holocene, Sediment, Structure characterization

We report the identification of a novel long-chain ketone in Holocene Black Sea sediments. Based on chemical properties, and chromatographic and mass spectrometric characteristics, this compound has been identified as a di-unsaturated C36 ethyl ketone. Further analyses indicated the position and configuration of the double bonds, and the novel alkenone was determined to be hexatriaconta-(16E,21E)-dien-3-one. While this compound is present in only trace quantities in Unit I sediments, it is the most abundant alkenone in portions of Unit II. Its presence thus apparently pre-dates the invasion of Emiliania huxleyi in the Black Sea. The down-core profiles and isotopic compositions suggest that the precursor for the C36:2 alkenone may be distinct from that of the C37-39 alkenones, however the biological origin of this novel compound is presently unknown.