Milli q rg apparatus

D-pinitol (95% mass), L-chiro-inositol (95% mass), myo-inositol (≥98% mass), D-glucose, D-fructose, and D-galactose were purchased from Sigma-Aldrich (Steinheim, Germany). Water, acetonitrile, methanol (all solvents were of LC-MS grade purity), trifluoroacetic acid (≥99% purity), and ammonium acetate (≥99% purity) were purchased from Sigma-Aldrich (Steinheim, Germany). MALDI matrices such as 2,5-dihydroxybenzoic acid (DHB), α-cyano-4-hydroxycinnamic acid (HCCA) as well as cesium triiodide for mass calibration were purchased from Sigma-Aldrich (Steinheim, Germany). Water was obtained with a Milli-Q RG apparatus by Millipore (Millipore Intertech, Bedford, MA, USA).

Cefotaxime (CEF), ciprofloxacin (CIP), fluconazole (FLU), gentamicin (GEN), clindamycin (KLI), linezolid (LIN), metronidazole (MET), and gemifloxacin (GEMI) (internal standard, IS) were obtained from Sigma-Aldrich (Schnelldorf, Mittelfranken, Germany). Glucose-6-phosphate, β-NADP+, Glucose-6-phosphate dehydrogenase, and uridine 5′-diphosphoglucuronic acid triammonium salt (UDPGA) were obtained from Sigma-Aldrich (Schnelldorf, Mittelfranken, Germany). Other chemicals of analytical quality (acetonitrile, formic acid) were purchased from Merck (Darmstadt, Germany). Microsomes derived from human liver cells (HLMs) at the concentration of 10 mg/vial were used in enzymatic studies. The microsomal fractions were stored at –80̊ °C and thawed immediately before each experiment. Ultrapure water was used for all analyses. Other chemicals were all analytical reagents. The water was obtained by means of Milli-Q RG apparatus by Millipore (Millipore Intertech, Bedford, MA, USA) in our laboratory. Drug-free urine was kindly provided by Nicolaus Copernicus University, Collegium Medicum, Torun (Poland) with Bioethical Commission permission (no. 639/2010).