δ12 pgd2

Methanol, acetonitrile,
isopropanol (all
LC-MS grade), formic acid (98–100%), and silver nitrate (AgNO₃, >99.8%) were purchased from Merck (Darmstadt, Germany).
Prostaglandin standards (PGE₂, PGD₂, Δ12-PGD₂, 8iso-PGE₂, 15(R)-PGE₂, ent-PGE₂, 11β-PGE₂, 5-trans-PGE₂, 15(R)-PGD₂, PGD₂-d₉, and PGF_2a-d₉) were purchased from Cayman Chemicals (MI, USA). Octadecanoyl
(18,18,18–d₃)-l-carnitine-HCl (C18-carnitine-d₃), arachidonic acid-d₈, and 10(Z),13(Z)-monononadecadienoin
(MG 19:2) were purchased from Larodan AB (Solna, Sweden). Lysophosphatidylcholine
19:0 (LPC 19:0), phosphatidylcholine 11:0/11:0 (PC 11:0/11:0), and
oleic acid-d₉ were purchased from Merck. Monoisotopic silver
(¹⁰⁷Ag) was purchased from Trace Sciences International
(Richmond Hill, ON, Canada), and a solution was prepared previously
in-house.^{33 (link)} Deionized water was obtained
from an in-house purification system (Millipore, Merck).

PGD₂, 13,14-dihydro-15-keto-PGD₂, PGJ₂, Δ¹²-PGJ₂, Δ¹²-PGD₂, 15-deoxy-Δ^12,14-PGJ₂, 15-deoxy-Δ^12,14-PGD₂, 9α,11β-PGF₂ were purchased from Cayman Chemicals (Biomol GmBH, Hamburg, Germany). Fevipiprant (GST0000013789) was provided by Novartis Pharma AG (Basel, Switzerland). Reagents were dissolved in sterile-filtered Hybri-Max dimethylsulfoxide (DMSO, Sigma-Aldrich, Taufkirchen, Germany).