Rhizochalins C and D from the Sponge <i>Rhizochalina incrustata.</i> A Rare <i>threo</i>-Sphingolipid and a Facile Method for Determination of the Carbonyl Position in α,ω-Bifunctionalized Ketosphingolipids
                                
                                    
                                        作者:Tatyana N. Makarieva、Pavel S. Dmitrenok、Alexander M. Zakharenko、Vladimir A. Denisenko、Alla G. Guzii、Ronghua Li、Colin K. Skepper、Tadeusz F. Molinski、Valentin A. Stonik                                    
                                    
                                        DOI:10.1021/np0704811
                                    
                                    
                                        日期:2007.12.1
                                    
                                    Rhizochalins C and D (1, 2), new representatives of two-headed glycosphingolipids, were isolated from the sponge Rhizochalina incrustata. Rhizochalin D is an unexpected C-29 homologue of the canonical C-28 dimeric sphingolipid structures. Their structures including absolute configurations were established using spectroscopic data, micromolar-scale Baeyer-Villiger oxidation, and LCMS interpretation of the products. Application of the latter method leads to a revision of the structure of oceanapiside and placement of the keto group at C-18 rather than C-11.