Sphinganine 1 phosphate

Human ovarian cancer cell line (A2780) and its taxol-resistant strain (A2780T) were purchased from KeyGen Biotech Co., Ltd. (Nanjing, China). The LIPID MAPS internal standard (IS) cocktail in ethanol, composed of 25 μM each of nine sphingolipid standards including SM (d18:1/12:0), Cer (d18:1/12:0), C1P (d18:1/12:0), HexCer (d18:1/12:0), LacCer (d18:1/12:0), Sphinganine (d17:0), Sphingosine (d17:1), Sphinganine-1-Phosphate (d17:0) and Sphingosine-1-Phosphae (d17:1), was purchased from Avanti Polar Lipids (Alabaster, AL, USA). HPLC-grade methanol (MeOH), chloroform (CHCl₃) and isopropanol (IPA) were purchased from Merck (Darmstadt, Germany). Ammonium acetate (NH₄OAc), potassium hydroxide (KOH), acetic acid (CH₃COOH) and formic acid (HCOOH) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Dulbecco’s Modified Eagle’s Medium (DMEM), Roswell Park Memorial Institute (RPMI) 1640 medium, Fetal Bovine Serum (FBS), Penicillin-Streptomycin (PS) were purchased from Gibco, New Zealand. Sodium dodecyl sulfate (SDS) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) were purchased from Acros, USA.
A pooled sample equally aliquoted from all samples can provide the most comprehensive information within a specific study. Hence, equivalent amount of A2780T was spiked into A2780 to prepare a pooled quality control (QC) sample.

The internal standard (IS) cocktail (LM-6005) consisting of 25 µM each of nine uncommon SPLs in ethanol including Sphinganine (d17:0), Sphingosine (d17:1), Sphinganine-1-Phosphate (d17:0) and Sphingosine-1-Phosphate (d17:1), Ceramide (d18:1/12:0), Ceramide (d18:1/25:0), Ceramide-1-Phosphate (d18:1/12:0), Hexosyl Ceramide (d18:1/12:0), Lactosyl Ceramide (d18:1/12:0) and Sphingomyelin (d18:1/12:0) was purchased from Avanti Polar Lipids (Alabaster, AL). Ammonium formate (NH₄HCO₂), potassium hydroxide (KOH), acetic acid (CH₃COOH) and formic acid (HCOOH) were purchased from Sigma-Aldrich (St. Louis, MO, USA). LC-MS-grade chloroform (CHCl₃), methanol (CH₃OH) and isopropanol (IPA) were purchased from Merck (Darmstadt, Germany). All other chemicals used were of analytical grade.

LC-MS grade solvents and reagents as water, methanol, ammonium formate, formic acid, and acetate acid, as well as 3,5-Di-tert-4-butylhydroxytoluene (BHT), were from Sigma-Aldrich (Saint Louis, MO, USA). Ethanol and HPLC analytical grade chloroform were, respectively, from J.T. Baker (Center Valley, PA, USA) and Carlo Erba (Cornaredo, MI, Italy). Potassium hydroxide was from Merk Millipore (Burlington, MA, USA). Sphingosine (d17:1), sphinganine-1-phosphate (d17:1), ceramide (d18:1/12:0), sphingomyelin (d18:1/12:0) and glucosyl (β)ceramide (d18:1/12:0) were from Avanti Polar Lipids (Alabaster, AL, USA).