A tryptophan-substituted cholic acid : expanding the family of labelled biomolecules

Research output: Contribution to journalArticle


The synthesis of a novel cholic acid derivative bearing in the C-3 position a residue of tryptophan linked through an amide bond is herein described. Acidic or basic conditions are needed for the solubilization of the derivative in water. In alkaline solutions the molecule shows a self-association similar to the one of its natural precursor leading to the formation of ellipsoidal micelles which does not involve significant Trp–Trp interactions. On the contrary, in acidic conditions strong interactions between the tryptophan moieties occur, leading to the formation of a gel at low temperature. These interactions are broken upon heating and small micelles similar to those observed at high pH are formed. In both cases, fluorescence spectra suggest a polar environment for the amino acid fluorophore not remarkably affected by the self-assembly.


  • Leana Travaglini
  • Marta Gubitosi
  • Maria Chiara di Gregorio
  • Andrea D'Annibale
  • Francisco Meijide
  • Mauro Giustini
  • Simona Sennato
  • Marc Obiols-Rabasa
  • Karin Schillén
  • Nicolae Viorel Pavel
  • Luciano Galantini
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Chemistry
Original languageEnglish
Pages (from-to)142-149
JournalColloids and Surfaces A: Physicochemical and Engineering Aspects
Issue numberOnline 31 March 2015
Publication statusPublished - 2015
Publication categoryResearch