Nonenzymatic formation of advanced glycation endproducts by glucosamine autocondensation and glucosamine with proteins
Advanced glycation endproducts (AGE) are a complex and heterogeneous group of compounds formed mainly by the nonenzymatic reactions of reducing sugars with amino acids and proteins. AGE accumulate in plasma and tissues with aging, diabetes, and renal failure. ^ Glucosamine (GlcN) nonenzymatically forms autocondensation glycation products under physiological conditions. Many studies have reported the effectiveness of oral doses of glucosamine alone or in combination with the galactosamine containing chondroitin in treating osteoarthritis. However, none of these studies have considered whether it is the glucosamine itself and/or one or more of its autocondensation products which exerts this effect. ^ Carnosine has been regarded largely as an anti-oxidant and free radical scavenger. More recently, its anti-glycating potential has been discovered. ^ In the present study, the reactions and possible structures involved in AGE formation were discussed. HPLC and capillary electrophoresis (CE) methods were developed to monitor and separate the nonenzymatic formation of autocondensation glycation products (“Type I”) of glucosamine, galactosamine and mannosamine, and Maillard reaction products (MRP) (“Type II”) from the nonenzymatic reaction of GlcN with two major proteins in human plasma, fibrinogen and serum albumin, under physiological conditions. Major components were detected by fluorescence and UV/Vis spectroscopy. The inhibitory effects of camosine on above reactions in vitro were investigated. ^
"Nonenzymatic formation of advanced glycation endproducts by glucosamine autocondensation and glucosamine with proteins"
Dissertations and Master's Theses (Campus Access).