Di potassium hydrogen phosphate trihydrate k2hpo4.3h2o

SEN (98%) was purchased from Phytolab (Phytolab GmbH and Co. KG, Germany) and was prepared in DMSO purchased from Acros Organics (Geel, Belgium). Acetonitrile (ACN, UPLC/MS grade) and methanol were purchased from Biosolve (Valkenswaard, the Netherlands). Di-potassium hydrogen phosphate trihydrate (K₂HPO₄.3H₂O) and potassium dihydrogen phosphate (KH₂PO₄) were purchased from Merck (Darmstadt, Germany). The reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) was purchased from Carbosynth (Carbosynth, United Kingdom). L-glutathione-reduced (GSH, purity ≥98%) was purchased from Sigma-Aldrich (St. Louis, MO, United States). Pooled rat liver S9 from male Sprague-Dawley (SD) rats was purchased from Corning (Amsterdam, the Netherlands).

Riddelliine (98%) and Riddelliine N-oxide (95%) were purchased from Phytolab (Phytolab GmbH & Co. KG, Germany). Dimethyl sulfoxide (DMSO) was obtained from Acros Organics (Geel, Belgium). Acetonitrile (UPLC/MS grade) and methanol were obtained from Biosolve (Valkenswaard, the Netherlands). Di-potassium hydrogen phosphate trihydrate (K₂HPO₄.3H₂O) and potassium dihydrogen phosphate (KH₂PO₄) were purchased from Merck (Darmstadt, Germany). The reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) was obtained from Carbosynth (Carbosynth, UK). Pooled liver and small intestine S9 from male Sprague–Dawley (SD) rats were obtained from Corning (Amsterdam, the Netherlands) and Xenotech (Kansas City, USA), respectively. Phosphate-Buffered Saline (PBS) was purchased from Gibco (Paisley, USA). Fresh fecal samples from Wistar rats (seven males and six females) were a gift from BASF (Ludwigshafen, Germany). In BASF, the samples were weighed, and transferred into anaerobic 10% v/v glycerol in PBS and were subsequently mixed and diluted to give a 20% w/v final fecal concentration. Next, these samples were filtered using sterile gauze under anaerobic conditions, and the resulting fecal slurry aliquots were stored at − 80 °C until use.