Glycation of N-ε-carboxymethyllysine

Abstract The Maillard reaction is traditionally subdivided into three stages that start consecutively and run in parallel. Here, we show N -ε-carboxymethyllysine (CML), a compound formed the late stage of reaction, can undergo second glycation event at its secondary amino group leading to new class Amadori rearrangement products. When -α-hippuryl-CML was incubated presence reducing sugars such as glucose, galactose, ribose, xylose, maltose, or lactose solution for 1 h 75 °C, degraded by 6–21%, -ε-carboxymethyl- -ε-deoxyketosyl lysine derivatives were formed. Under same conditions, 5–10 times more reactive than CML. -α-hippuryl- -ε-(1-deoxyfructosyl)- l -lysine (hippuryl-CMFL) (CMFL) synthesized, isolated characterized MS/MS NMR experiments. Depending on up 21% CMFL be converted furosine analogue -ε-furoylmethyl- (CM-Fur) during standard acid protein hydrolysis with hydrochloric acid. Incubation bovine serum albumin (BSA) glucose 9 weeks 37 °C revealed formation assessed HPLC–MS/MS MRM mode. these ca. 13% residues had been fructosyllysine, 0.03% CMFL. detection products glycated acids (heterogeneous multiple glycation) reveals novel pathway reaction.