O-N intramolecular acyl migration strategy in water-soluble prodrugs of taxoids

Bioorg Med Chem Lett. 2003 Dec 15;13(24):4441-4. doi: 10.1016/j.bmcl.2003.09.020.

Abstract

We synthesized a highly water-soluble canadensol prodrug 6 that formed canadensol 3 by a simple pH-dependent chemical mechanism via the O-N intramolecular acyl migration of the isobutyryl group. This prodrug, a 2'-O-isobutyryl isoform of 3, has no additional functional auxiliaries released during the conversion to 3. This is a significant advantage in toxicology and medical economics, since the potential side effects of reported water-soluble auxiliaries and the use of detergent for solubilization can be avoided. The solubility of 6 was 2.26 mg mL(-1) and only the parent drug 3 was released under physiological conditions (pH=7.4) while, in acidic medium, the release of 3 slowed until migration was completely obstructed at pH=2. In further consideration of this strategy, we elucidated the use of an 'O-N acyl-like' migration reaction of the Boc group in the design of a docetaxel prodrug. Both O-N migration and undesired hydrolysis of the Boc group occurred under physiological conditions, although no oxazolidinone formation was observed, suggesting the limitation of our water-soluble prodrug strategy to docetaxel.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acylation
  • Indicators and Reagents
  • Kinetics
  • Models, Molecular
  • Molecular Conformation
  • Nitrogen
  • Oxygen
  • Prodrugs / chemical synthesis
  • Prodrugs / chemistry*
  • Solubility
  • Stereoisomerism
  • Taxoids / chemical synthesis*
  • Taxoids / chemistry*
  • Water

Substances

  • Indicators and Reagents
  • Prodrugs
  • Taxoids
  • Water
  • Nitrogen
  • Oxygen