L rhamnulose

Standard substances such as L-rhamnulose and L-rhamnose were purchased from Sigma-Aldrich (USA). Electrophoresis reagents, the genomic DNA minipreparation kit with a spin column, the polymerase chain reaction (PCR) kit, and isopropyl β-D-1thiogalactopyranoside (IPTG) were purchased from Beyotime Institute of Biotechnology (China). Restriction enzymes and T4 DNA ligase were purchased from New England Biolabs (USA). A DNA gel extraction kit was purchased from Generay Biotech (China). A universal DNA purification kit was obtained from Tiangen Biotech Co., Ltd. (China). All other reagents (analytical grade) were purchased from Sinopharm Chemical Reagent Co., Ltd. (China).

Healthy human blood serum (S7023-50 mL) was purchased from Sigma-Aldrich (St. Louis, MO). FMOC-L-proline was procured from Chem-Impex International (Wood Dale, IL). Leucine enkephalin was obtained from ERA (Golden, CO). Arginyl-glycyl-aspartic acid, L-fucose, L-rhamnose, 1,5-anhydrosorbitol, D-fucose, L-rhamnulose, 2-deoxy-D-glucose, and 2deoxy-D-galactose were acquired from Sigma-Aldrich Bilirubin, and suberic acid was obtained from Alfa Aesar (Ward Hill, MA). Ricinoleic acid was purchased from MP Biomedicals (Santa Ana, CA). Docosahexaenoic acid and 3-oxo stearic acid were acquired from Cayman Chemical Company (Ann Arbor, MI). LysoPE(16:0) was obtained from Avanti Polar Lipids (Alabaster, AL). LC-MS grade methanol was purchased from J.T. Baker Avantor Performance Materials (Center Valley, PA). Ultrapure water with 18.2 MΩ cm resistivity (Barnstead Nanopure, Thermo Fisher Scientific, Waltham, MA) was used to prepare chromatographic mobile phases.