2 4 dinitrophenylhydrazone

All the chemicals were purchased from commercial sources and were used with no further purification process (CoCl₂·6H₂O, NiCl₂·6H₂O and KSCN) from Merck, and 2,4-dinitrophenylhydrazone was obtained from Sigma Aldrich, along with the solvents like DMSO, DMF, acetone, ethanol and methanol, used as AnalaR grade.

METH hydrochloride (Ref D816) was procured from NMI, Australia. The identity of the purchased METH was confirmed by gas chromatography–mass spectrometry (GC-MS). Mannan, 2,4-dinitrophenylhydrazone, collidine, sodium periodate (NaIO₄), 1-hydroxy-7-azabenzotriazole (HOAt), dithiothreitol (DTT), 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethylaminium tetrafluoroborate (TBTU) and Ninhydrin^® were purchased from Sigma Aldrich, (Australia) and used without further purification. The peptide linker [(KG)₅] with a purity of >85% was procured from Synpeptide (Shanghai, China). All other reagents and chemicals used in this study were of analytical standard and used without further potency adjustment or purification.

From Bio Whittaker Europe (Lonza, Madrid, Spain), we acquired Dulbecco’s modified eagle’s medium (DMEM) and fetal calf serum (FCS). The three metabolites, DHCA, DHFA, and HHA; the antibiotics gentamicin, streptomycin, and penicillin; O-phthaldialdehyde (OPT); glutathione reductase (GR); reduced glutathione (GSH) and oxidized glutathione (GSSG); dichlorofluorescein diacetate (DCFH-DA); 2,4-di-nitrophenylhydrazone (DNPH); nicotinamide adenine dinucleotides phosphates (NADPH); β-mercaptoethanol; guanidine; dithiothreitol (DTT); ethylenediaminetetraacetic acid (EDTA); dimethylsulphoxide (DMSO); and sodium dodecyl sulphate (SDS) were bought from Sigma-Aldrich (Madrid-Spain). From Bio-Rad (Madrid, Spain), the Bradford reagent was purchased. TNF-α, a recombinant murine agent, was from PreproTech (Tebu-bio, Madrid, Spain). From Invitrogen by ThermoFisher Scientific (Madrid, Spain), we obtained the IL-6 ELISA kit. The cell culture dishes were obtained from Falcon (Cajal, Madrid, Spain). The 3T3-L1 cells were a donation from Dr. Angela Martinez-Valverde from the IIB Alberto Sols (CSIC-UAM). The remaining chemicals used were of analytical grade.