The (R)-enantiomer (1) of methyl (5Z,9Z)-17-methyl-nonadeca-5,9-dienoate, the structure proposed for a metabolite of the Philippine sponge, Plakinastrella sp., was synthesized. The 1H- and 13C-NMR spectra of the synthetic material were different from those reported for the natural product. The proposed structure 1 is therefore incorrect.
                                    合成了甲基(5Z,9Z)-17-甲基-十九烯-5,9-二酸酯的(R)-对映体(1),该结构为
菲律宾海绵Plakinastrella sp.的代谢物。合成材料的1H和13C-NMR谱图与自然产物报告的谱图不同。因此,提出的结构1是不正确的。