Isodesmosine is prepared according to the method of Starcher, et al. from hdrolyzed bovine neck ligament by solvent extraction and chromatography on Dowex 50.

Desmosine is a tetrafunctional, pyridinium ring-containing amino acids involved in elastin cross-linking. A desmosine cross-link is formed from three allysyl side chains plus one unaltered lysyl side chain from the same or neighbouring polypeptides. Desmosine is responsible for the cross-linking…