Title
Modification of β-cyclodextrin through solution ring-opening oligomerization of β-butyrolactone
Authors
CRISTIAN PEPTU, IWONA KWIECIEN VALERIA HARABAGIU BOGDAN C. SIMIONESCU and MAREK KOWALCZUK

Received September 29, 2013
Published Volume 48 Issue 1-2 January-February
Keywords β-cyclodextrin, β-butyrolactone, electrospray mass spectrometry, sparteine, polyester, liquid chromatography

Abstract
β-cyclodextrin (CD) derivatives were prepared through ring-opening of β-butyrolactone (BL) in DMSO solution initiated by CD at relatively low temperature in the presence of (-)-sparteine (SP) as nucleophilic activator. The reaction was proved to yield a mixture of polyhydroxybutyrate (PHB) and 3-OH butyrated cyclodextrin derivatives (CD-HB). Following separation, the resulted products were thoroughly characterized through NMR spectroscopy and electrospray ionization mass spectrometry (ESI MS) coupled with liquid chromatography (LC). The CD-HB products are described in view of their substitution degree, substitution pattern at glycoside ring level and length of the oligomer chains attached to the CD, taking into account both NMR and ESI MS characterization methods. The kinetics of β butyrolactone ring-opening in the presence of CD and SP is evaluated through 1H NMR spectroscopy showing that secondary processes are contributing to the monomer conversion.