Synthesis of N-acetyl-D-galactosamine and folic acid conjugated ribozymes

Bioconjug Chem. 2002 Sep-Oct;13(5):1071-8. doi: 10.1021/bc025525q.

Abstract

To evaluate potential improvement in tissue specific targeting and cellular uptake of therapeutic ribozymes, we have developed three new phosphoramidite reagents. These reagents can be used in automated solid-phase synthesis to produce oligonucleotide conjugates containing N-acetyl-D-galactosamine (targeting hepatocytes) and folic acid (targeting tumor). N-Acetyl-D-galactosamine was attached through a linker to both 2'-amino-2'-deoxyuridine and D-threoninol scaffolds, and these conjugates were converted to phosphoramidite building blocks. Incorporation of a D-threoninol-based monomer into ribozymes provided multiply labeled ribozyme conjugates. Attachment of the fully protected pteroic acid to the D-threoninol-6-aminocaproyl-L-glutamic acid construct afforded the folic acid conjugate, which was converted into the phosphoramidite and incorporated onto the 5'-end of the ribozyme.

MeSH terms

  • Acetylgalactosamine / chemistry
  • Antineoplastic Agents / chemical synthesis
  • Cross-Linking Reagents / chemistry
  • Drug Delivery Systems / methods*
  • Folic Acid / chemistry
  • Oligonucleotides / chemical synthesis
  • Organophosphorus Compounds / chemistry
  • RNA, Catalytic / administration & dosage*
  • RNA, Catalytic / chemistry

Substances

  • Antineoplastic Agents
  • Cross-Linking Reagents
  • Oligonucleotides
  • Organophosphorus Compounds
  • RNA, Catalytic
  • phosphoramidite
  • Folic Acid
  • Acetylgalactosamine