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At the designated time points, whole blood or TSB samples were centrifuged for 2 min at 13,523 x g, 4 ºC. The supernatant was vortexed and mixed with cold methanol (v/v ratio 1:2). All samples mixed with methanol were centrifuged for 2 minutes at 4 ºC, 15,871 x g. Supernatant was added to Spin-X centrifuge tubes (Corning Inc., Corning, NY) and centrifuged at 4 ºC, 15,871 x g one more time. , Bacteria was quenched by a mixture of methanol/acetonitrile/H2O (40:40:20). Then, metabolites were extracted by mechanical disruption with 0.07–0.1 mm glass beads using a tissue homogenizer. Lysates were filtered through a 0.2-μm microcentrifuge filter.

Extracted metabolites were separated using Cogent diamond hydride type C column. The gradient elution of metabolites was conducted using solvent A (DDW with 0.2% formic acid) and solvent B (acetonitrile with 0.2% formic acid). Detailed condition for gradient elution is as follows: 0–2 min, 85% B; 3–5 min, 80% B; 6–7 min, 75%; 8–9 min, 70% B; 10–11.1 min, 50% B; 11.1–14 min 20% B; 14.1–24 min 5% B followed by a 10 min re-equilibration time at a flow rate of 0.4 mL/min.

LC-MS analysis for metabolic profiling was conducted using Agilent time-of-flight(TOF) mass spectrometry coupled with Agilent 1290 liquid chromatography system.