a MS Traces MS/MS Traces 10x10° N-palmitoyl serinol N-palmitoyl serinol Mouse 1 Control 50x1 Mouse 2 Treatment Mouse 2 Control 人 Mouse 1 Treatment 912014016002002224020210300220340260 Mouse 2 Treatment a, LC-MS analysis of crude cecal extracts. Extracted-ion chromatograms for palmitoyl I([M+H] m/z 3303003)are shown. A peak hromatographic retention time as the N-palmitoyl serinol standard was present in treatment mice but not control mice. Treatment mice were colonized with E coli containing the N-acyl serinol synthase gene Control mice were colonized with E. coli containing the empty pET28e vector. b, Identification of N-palmitoyl serinol by MS/MS fragmentation of the m/z 330.3003 ion In the Ms2 spectrum the diamond indicates N-palmitoyl serinol parent ion and the product ion at m/z. 92.0706 shows presence of the serinol head group Nature. Author manuscript; available in PMC 2018 February 28Extended Data Figure 6. Identification of N-acyl serinol biosynthesis in vivo a, LC-MS analysis of crude cecal extracts. Extracted-ion chromatograms for palmitoyl serinol ([M+H]+ m/z: 330.3003) are shown. A peak with the same exact mass and chromatographic retention time as the N-palmitoyl serinol standard was present in treatment mice but not control mice. Treatment mice were colonized with E. coli containing the N-acyl serinol synthase gene. Control mice were colonized with E. coli containing the empty pET28c vector. b, Identification of N-palmitoyl serinol by MS/MS fragmentation of the m/z 330.3003 ion. In the MS2 spectrum the diamond indicates N-palmitoyl serinol parent ion and the product ion at m/z: 92.0706 shows presence of the serinol head group. Cohen et al. Page 20 Nature. Author manuscript; available in PMC 2018 February 28. Author Manuscript Author Manuscript Author Manuscript Author Manuscript