Synthesis of glycosylated 5-hydroxylysine, an important amino acid present in collagen-like proteins such as adiponectin

The synthesis of naturally occurring glycosylated (2S,5R)-hydroxylysine still remains a challenge. This perspective highlights the importance of this post-translationally modified amino acid residue in the observed bioactivity of collagen and related collagen-like proteins such as adiponectin, an important target for the treatment of type II diabetes. Strategies employed to date for the syntheses of (2S,5R)-hydroxylysine and the methods to effect glycosylation of this modified amino acid are also summarized herein.