Figure 1.

Pathways of early and advanced glycation (oxidative glycosylation [12], Namiki pathway [13], enolization [14], oxidative [15] and non-oxidative (enolization and dehydration stages are not mentioned) [16] degradation of early glycation products, polyol pathway [17] and lipid peroxidation [18] (a) and structures of major AGEs detected in vivo and in thermally processed foods (b)). R₁, R₂, R₃, R₄, R₅, polypeptide chains; R₁′, R₂′, R₃′, fatty acid residues; R₁′′ = H, R₂′′ = H for glyoxal; R₁′′ = H, R₂′′ = CH₃ for methylglyoxal; R1′′ = H, R2′′ = C₄H₉O₃ for 3-DG. * Ketoses form so-called Heyns products.