Conjugation of bile esters to cellulose by olefin cross-metathesis: A strategy for accessing complex polysaccharide structures

Carbohydr Polym. 2019 Oct 1:221:37-47. doi: 10.1016/j.carbpol.2019.05.061. Epub 2019 May 25.

Abstract

Bile salts tend to form micelles in aqueous media and can thereby contribute to drug solubilization; they also exhibit crystallization inhibition properties that can stabilize supersaturated drug solutions. Herein, we explore conjugation of bile salts with polysaccharides to create new, amphiphilic polysaccharide derivatives with intriguing properties, portending broad utility in various applications. We introduce efficient conjugation of cholesterol (as a model steroid), lithocholic acid, and deoxycholic acid by mild, modular olefin cross-metathesis reactions. These small molecules were first modified with an acrylate group from the A-ring hydroxyl, then reacted with cellulose derivatives bearing olefin-terminated metathesis "handles". Successful conjugation of bile acids has demonstrated chemoselective cross-metathesis with complex, polyfunctional structures, and large multi-ring systems. It also enabled an efficient, general pathway for polysaccharide-bile salt conjugates, which promise synergy for applications such as amorphous solid dispersion (ASD).

Keywords: Amorphous solid dispersion; Bile salt; Bioavailability; Cellulose; Cross-metathesis; Oral drug-delivery.

MeSH terms

  • Cellulose / chemical synthesis
  • Cellulose / chemistry*
  • Cholesterol / analogs & derivatives*
  • Cholesterol / chemical synthesis
  • Deoxycholic Acid / analogs & derivatives*
  • Deoxycholic Acid / chemical synthesis
  • Esters / chemical synthesis
  • Esters / chemistry*
  • Lithocholic Acid / analogs & derivatives*
  • Lithocholic Acid / chemical synthesis
  • Lithocholic Acid / chemistry
  • Proof of Concept Study
  • Solubility

Substances

  • Esters
  • Deoxycholic Acid
  • methyl lithocholate
  • Lithocholic Acid
  • Cellulose
  • Cholesterol
  • microcrystalline cellulose