An Amino Acid Derived from Aldol Crosslink of Elastin and Collagen: Structure, Distribution, Aging, and Two Models of Hyperglycemia

A novel amino acid named aldosine was isolated from acid hydrolysates of bovine aorta elastin. The mass spectral analysis of aldosine indicated a parent compound with a mass of 256 (C12H20N2O4). From the structure identified by spectroscopy of aldosine and its derivatives, it was deduced that aldosine was derived from aldol crosslink and dehydromerodesmosine of elastin and collagen. The aldosine content in aorta of newborn rats was very low, but increased markedly with growth. After maturity was reached, the aldosine content decreased. The aldosine content in bovine aorta decreased gradually from 7 months to 16 years of age. Aldosine was also quantified in the aorta and tail tendon of rats in two models of hyperglycemia: diabetes and galactosemia. Hyperglycemias were significantly affected on aldosine content of organs. In both diabetic and galactosemic animals, aldosine was remarkably lower relative to controls (about one-half and one-sixth, respectively).