Novel design and synthesis of a radioiodinated glycolipid analog as an acceptor substrate for N-acetylglucosaminyltransferase V.

Guided by the known molecular recognition interactions between N-acetylglucosaminyltransferase V (GnT-V) and certain synthetic substrates, we synthesized a radiolabeled double-stranded glycolipid composed of a long-chain alkyl unit and a radioiodinated phenylalkyl unit, [125I]-2-[N-(2-hydroxy-3-hexadecyloxy)propyl-15-(4-iodophenyl)pentadecanecarboxamido]ethyl 2-acetamido-2-deoxy-β-d-glucopyranosyl-(12)-α-d-mannopyranosyl-(16)-β-d-glucopyranoside ([125I]2), as a novel intravital glycolipid mimic substrate of GnT-V. The radioactive iodine (125I) was incorporated via iododestannylation of the phenyltributyltin derivative, 2-[N-(2-acetoxy-3-hexadecyloxy)propyl-15-(4-tributylstannylphenyl)pentadecanecarboxamido]ethyl 3,4,6-tri-O-acetyl-2-acetamido-2-deoxy-β-d-glucopyranosyl-(12)-3,4,6-O-acetyl-α-d-mannopyranosyl-(16)-2,3,4-tri-O-acetyl-β-d-glucopyranoside (26). Subsequent deacetylation at the final step afforded [125I]2.