The Occurrence of the Human Glycoconjugate <i>C</i><sup>2</sup>-α-d-Mannosylpyranosyl-l-tryptophan in Marine Ascidians

The <i>C</i>-glycoconjugate <i>C</i><sup>2</sup>-α-d-mannosylpyranosyl-l-tryptophan (<b>1</b>), a metabolite known to be generated in humans through a novel posttranslational process, has been isolated from marine ascidians <i>Leptoclinides dubius</i> and <i>Pharyngodictyon cauliflos </i>and its <i>N</i><sup>α</sup>-methyl derivative (<b>2</b>) from <i>Ritterella rete.</i>