3-Deoxyglucosone, an intermediate product of the Maillard reaction.

The Maillard reactions between proteins and glucose or fructose, in 0.2M phosphate buffer (pH 7.4) at 37 degrees C, were investigated and the following results were obtained: 1) 3-deoxyglucosone (3DG) is formed as the major carbonyl intermediate; 2) fructose has a higher reactivity than glucose and 3DG is formed also from fructose without involvement of amino groups; 3) 3DG is a crosslinker responsible for polymerization of proteins; 4) 3DG is involved in the formation of a fluorescent advanced-stage product named "Peak L1" in vitro and in vivo.