biostudies-literatureSidhu REunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNCATS NIH HHSNIDDK NIH HHSAra Parseghian Medical Research FoundationNHLBI NIH HHSNINDS NIH HHSNational Institutes of HealthNIGMS NIH HHSNIH HHS1410-1424https://www.ebi.ac.uk/biostudies/studies/S-EPMC6672039biostudies-literatureUnknown60(8)Niemann-Pick disease type C1 (NPC1) is a fatal, neurodegenerative, cholesterol storage disorder. With new therapeutics in clinical trials, there is an urgency to improve diagnostics and monitor therapeutic efficacy with biomarkers. In this study, we sought to define the structure of an unknown lipid biomarker for NPC1 with [M + H]⁺ ion at <i>m/z</i> 509.3351, previously designated as lysoSM-509. The structure of <i>N</i>-palmitoyl-<i>O</i>-phosphocholineserine (PPCS) was proposed for the lipid biomarker based on the results from mass spectrometric analyses and chemical derivatizations. As no commercial standard is available, authentic PPCS was chemically synthesized, and the structure was confirmed by comparison of endogenous and synthetic compounds as well as their derivatives Journal of lipid research<i>N</i>-acyl-<i>O</i>-phosphocholineserines: structures of a novel class of lipids that are biomarkers for Niemann-Pick C1 disease.PMC66720392R01DK067859R01 NS081985UL1 TR002345T32 HL007081P41 GM103422P40 OD010939P30 DK020579R01 DK067859P41-GM103422UL1 TR000448P30 DK056341Berry-Kravis ESidhu RSong HYanjanin NMKumar ABHsu FFPorter FDMondjinou YHong XVite CHGelb MHOry DSJiang XDietzen DJSchaffer JEQian Mfalse<i>N</i>-acyl-<i>O</i>-phosphocholineserines: structures of a novel class of lipids that are biomarkers for Niemann-Pick C1 disease.Niemann-Pick disease type C1 (NPC1) is a fatal, neurodegenerative, cholesterol storage disorder. With new therapeutics in clinical trials, there is an urgency to improve diagnostics and monitor therapeutic efficacy with biomarkers. In this study, we sought to define the structure of an unknown lipid biomarker for NPC1 with [M + H]⁺ ion at <i>m/z</i> 509.3351, previously designated as lysoSM-509. The structure of <i>N</i>-palmitoyl-<i>O</i>-phosphocholineserine (PPCS) was proposed for the lipid biomarker based on the results from mass spectrometric analyses and chemical derivatizations. As no commercial standard is available, authentic PPCS was chemically synthesized, and the structure was confirmed by comparison of endogenous and synthetic compounds as well as their derivatives 2019-01-01T00:00:00Z2019 Aug2025-04-29T10:31:19.858Z2020-10-29T08:40:30ZS-EPMC66720393120129110.1194/jlr.RA11900015710.1194/jlr.ra119000157