On the structure of PHB (=Poly[(R)-3-hydroxybutanoic acid]) in phospholipid bilayers: Preparation of trifluoromethyl-labeled oligo[(R)-3-hydroxybutanoic acid] derivatives

Oligomers of (R)-3-hydroxybutanoate (OHB) have previously been shown to transport cations through lipid bilayers. The ion-transport activity has been attributed to the formation of hydrophobic aggregates or pores, which have been identified by fluorescence-microscopy measurements of membrane-incorporated fluorescence-labeled OHBs. To obtain more information about these aggregates, we describe here the synthesis of the specifically F-labeled HB oligomers II-IV for structural investigation by means of solid-state ¹⁹F-NMR spectroscopic techniques.