Synthesis of beta-galactose-conjugated chlorins derived by enyne metathesis as galectin-specific photosensitizers for photodynamic therapy

J Org Chem. 2001 Dec 28;66(26):8709-16. doi: 10.1021/jo0105080.

Abstract

A first report on the synthesis and biological evaluation of the beta-galactose-conjugated purpurinimides (a class of chlorins containing a six-membered fused imide ring system) as Gal-1 (galectin-1) recognized photosensitizers, prepared from purpurin-N-propargylimide via enyne metathesis, is discussed. On the basis of examination of the available crystal structure of the galectin-1 N-acetyllactose amine complex, it was considered that the chlorin-based photosensitizers could be introduced into a carbohydrate skeleton to expand the repertoire of the galectin-1-specific ligands. Preliminary molecular modeling analysis utilizing the modeled photosensitizers and the available crystal structures of galectin-carbohydrate complexes indicated that addition of the photosensitizer to the carbohydrate moiety at an appropriate position does not interfere with the galectin-carbohydrate recognition. Under similar drug and light doses, compared to the free purpurinimide analogue, the purpurinimides conjugated either with galactose or with lactose (Gal(beta1-4)-Glc) produced a considerable increase in photosensitizing efficacy in vitro. This indicates the possibility for development of a new class of specific photosensitizers for photodynamic therapy (PDT) based on recognition of a cellular receptor.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Carbohydrates / chemical synthesis
  • Galactose / chemistry*
  • Galectins
  • Hemagglutinins / chemistry*
  • Humans
  • Light
  • Models, Molecular
  • Photochemotherapy
  • Porphyrins / chemical synthesis*
  • Porphyrins / chemistry
  • Porphyrins / pharmacology
  • Radiation-Sensitizing Agents / chemical synthesis*
  • Radiation-Sensitizing Agents / pharmacology
  • Tumor Cells, Cultured

Substances

  • Carbohydrates
  • Galectins
  • Hemagglutinins
  • Porphyrins
  • Radiation-Sensitizing Agents
  • chlorin
  • Galactose