Decoding Aging: Understanding the Complex Relationship among Aging, Free Radicals, and GSH

Figure 1

Proposed reaction mechanism for 3,5-dimaleimylbenzoic (3,5-DMB) acid with glutathione (GSH). The α,β-unsaturated carbonyl structure in 3,5-DMB acts as an electrophile, carrying out a 1,4-Michael-type reaction with the sulfur atom (S) from the thiol group of the cysteine residue in GSH (IUPAC-based numerical assignment). The β-carbon atom (C₃) is shown as the preferred site of attack due to its positive polarization, whereas GSH acts as a Michael acceptor because of its high reactivity toward soft electrophiles, such as α,β-unsaturated compounds.