Water, isopropanol, and acetonitrile were purchased from Fisher Optima. Methanol was purchased from J.T. Baker. Ammonium formate, formic acid and methyl tert-butyl ester (MTBE) were purchased from Sigma Aldrich. Authentic standard compounds were purchased from Avanti Polar Lipids Inc., CDN Isotopes, Cayman Chemical, and Sigma Aldrich.
For hydrophilic interaction chromatography-MS/MS analysis of pharmaceutical agents present in a human plasma sample, all procedures for the metabolite extraction were kept on ice. 30 µL of human plasma was added to 1000 µL cold mix-solvent (acetonitrile/isopropanol/water, 3:3:2, v/v/v) on ice, then vortexed for 10 s, and shaken for 5 min at 4 °C using the Orbital Mixing Chilling/Heating Plate (Torrey Pines Scientific Instruments). After 2 min centrifugation at 14,000 rcf, 300 µL of the supernatant was transferred to a new 1.5 mL Eppendorf tube and evaporated to dryness in a Labconco Centrivap cold trap concentrator. The dried sample was re-suspended with 60 µL (80% acetonitrile in water) including 0.038 µg/mL choline-D9, 0.050 µg/mL TMAO-D9, 0.020 µg/mL betaine-D9, 10.0 µg/mL glutamine-D5, and 1.48 µg/mL arginine-15N2 and centrifuged for 5 min at 16,000 rcf. The 50 µL aliquot was transferred to a glass amber vial (National Scientific) with a micro-insert (Supelco).
For lipid profiling, all samples for the metabolite extraction were kept on ice and performed as described previously34 . 225 µL of MeOH including 1.64 µg/mL PE (17:0/17:0), 6.55 µg/mL PG (17:0/17:0), 1.10 µg/mL PC (17:0/0:0), 0.24 µg/mL sphingosine (d17:1), 0.55 µg/mL ceramide (d18:1/17:0), 0.44 µg/mL SM (d18:1/17:0), 54.5 µg/mL palmitic acid-D3, 0.44 µg/mL PC (12:0/13:0), 22.7 µg/mL cholesterol-D7, 0.27 µg/mL TAG (17:0/17:1/17:0), 2.18 µg/mL DAG (12:0/12:0/0:0), 13.1 µg/mL DAG (18:1/2:0/0:0), 4.36 µg/mL MAG (17:0/0:0/0:0), and 0.55 µg/mL PE (17:1/0:0) were added to each dried algae on ice and vortexed for 10 seconds. Then, the MTBE including 21.8 µg/mL cholesteryl ester (22:1) was added on ice and vortexed for 10 seconds. After shaking for 6 min at 4 °C in the orbital mixer, 188 µL water was added and vortexed for 20 s. After centrifugation for 2 min at 14,000 rcf, 350 µL of the supernatant was transferred to a new 1.5 mL Eppendorf tube and evaporated to dryness in the Labconco Centrivap cold trap concentrator. The dried sample was re-suspended in 108.6 µL MeOH:toluene 90:10 (v/v) with CUDA (12-[[(cyclohexylamino)carbonyl]amino]-dodecanoic acid, 50 ng/mL). After vortexing for 20 s, each sample was sonicated for 5 min at room temperature. After centrifugation for 2 min at 16,000 rcf, 50 µL of the supernatant was transferred to a glass amber vial with micro-insert. The C. reinhardtii, C. sorokiniana, and C. variabilis samples were diluted by adding 50 µL of MeOH:toluene 90:10 (v/v). Moreover, the E. gracilis sample was diluted by adding 200 µL of MeOH:toluene 90:10 (v/v).
For hydrophilic interaction chromatography-MS/MS analysis of pharmaceutical agents present in a human plasma sample, all procedures for the metabolite extraction were kept on ice. 30 µL of human plasma was added to 1000 µL cold mix-solvent (acetonitrile/isopropanol/water, 3:3:2, v/v/v) on ice, then vortexed for 10 s, and shaken for 5 min at 4 °C using the Orbital Mixing Chilling/Heating Plate (Torrey Pines Scientific Instruments). After 2 min centrifugation at 14,000 rcf, 300 µL of the supernatant was transferred to a new 1.5 mL Eppendorf tube and evaporated to dryness in a Labconco Centrivap cold trap concentrator. The dried sample was re-suspended with 60 µL (80% acetonitrile in water) including 0.038 µg/mL choline-D9, 0.050 µg/mL TMAO-D9, 0.020 µg/mL betaine-D9, 10.0 µg/mL glutamine-D5, and 1.48 µg/mL arginine-15N2 and centrifuged for 5 min at 16,000 rcf. The 50 µL aliquot was transferred to a glass amber vial (National Scientific) with a micro-insert (Supelco).
For lipid profiling, all samples for the metabolite extraction were kept on ice and performed as described previously34 . 225 µL of MeOH including 1.64 µg/mL PE (17:0/17:0), 6.55 µg/mL PG (17:0/17:0), 1.10 µg/mL PC (17:0/0:0), 0.24 µg/mL sphingosine (d17:1), 0.55 µg/mL ceramide (d18:1/17:0), 0.44 µg/mL SM (d18:1/17:0), 54.5 µg/mL palmitic acid-D3, 0.44 µg/mL PC (12:0/13:0), 22.7 µg/mL cholesterol-D7, 0.27 µg/mL TAG (17:0/17:1/17:0), 2.18 µg/mL DAG (12:0/12:0/0:0), 13.1 µg/mL DAG (18:1/2:0/0:0), 4.36 µg/mL MAG (17:0/0:0/0:0), and 0.55 µg/mL PE (17:1/0:0) were added to each dried algae on ice and vortexed for 10 seconds. Then, the MTBE including 21.8 µg/mL cholesteryl ester (22:1) was added on ice and vortexed for 10 seconds. After shaking for 6 min at 4 °C in the orbital mixer, 188 µL water was added and vortexed for 20 s. After centrifugation for 2 min at 14,000 rcf, 350 µL of the supernatant was transferred to a new 1.5 mL Eppendorf tube and evaporated to dryness in the Labconco Centrivap cold trap concentrator. The dried sample was re-suspended in 108.6 µL MeOH:toluene 90:10 (v/v) with CUDA (12-[[(cyclohexylamino)carbonyl]amino]-dodecanoic acid, 50 ng/mL). After vortexing for 20 s, each sample was sonicated for 5 min at room temperature. After centrifugation for 2 min at 16,000 rcf, 50 µL of the supernatant was transferred to a glass amber vial with micro-insert. The C. reinhardtii, C. sorokiniana, and C. variabilis samples were diluted by adding 50 µL of MeOH:toluene 90:10 (v/v). Moreover, the E. gracilis sample was diluted by adding 200 µL of MeOH:toluene 90:10 (v/v).