The introduction of a 2,3 - disubstituted pyridine ring with an aminomethyl moiety at the 2 - position led to compound 142 with an IC50 value of 0.021 μM that showed a comparable potency to 131. (thno.org)
«Distant Protonated Pyridine Groups in Water - Soluble Iron Porphyrin Electrocatalysts Promote Selective Oxygen Reduction to Water.» (pnnl.gov)
TPN then becomes negative and at the same time attracts a proton, forming TPNH, the reduced pyridine nucleotide. (customwritingservices.org)