N lignoceroyl d erythro sphingosylphosphorylcholine

HPLC grade isopropanol, methanol (MeOH), and acetonitrile (ACN) were purchased from Merck Millipore (United States). Formic acid was purchased from Sigma-Aldrich (United States). PL standards l,2-dipalmitoyl-sn-glycero-3-phosphocholine (PC 16:0/16:0), l,2-distearoyl-sn-glycero-3-phosphoethanolamine (PE 18:0/18:0), N-lignoceroyl-D-erythro-sphingosylphosphorylcholine (SM d18:1/24:0) and l-stearoyl-2-arachidonoyl-sn-glycero-3-phosphoinositol (PI 18:0/20:4) (ammonium salt) were purchased from Avanti Polar Lipids (Alabama, United States). Ultrapure water (18.0 MΩ cm at 25°C) was obtained from a Milli-Q water system (Millipore, United States).

1,2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC), N-lignoceroyl-D-erythro-sphingosylphosphorylcholine (24:0 SM, lSM), N-nervonoyl-D-erythro-sphingosyl-phosphorylcholine (24:1 SM, nSM), N-lignoceroyl-D-erythro-sphingosine (24:0 Cer, lCer), N-nervonoyl-D-erythro-sphingosine (24:1 Cer, nCer), cholesterol (Chol), and the lipophilic fluorescent probe 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(lissamine rhodamine B sulfonyl) (Rho-PE) were purchased from Avanti Polar Lipids (Alabaster, AL). DiI (1,1′-Dioctadecyl-3,3,3′,3′-Tetramethylindocarbocyanine Perchlorate ('DiI'; DiIC18(3))) was supplied by Thermo Fisher (Waltham, MA, USA). Methanol and chloroform were from Fisher (Suwanee, GA). Buffer solution, unless otherwise stated, was 20 mM PIPES, 1 mM EDTA, 150 mM NaCl, pH 7.4. All salts and organic solvents were of analytical grade.