Several hydroxypropyl-β-cyclodextrins (HP-β-CDs) with various degree of substitution and different positi0n of substituti0n were synthesized. The average degree of substi-tution (Ds) of HP-g-CD were determined by fast atom bombardment mass spectrometry(FAB-MS). The effects of the Ds of HP-β-CD on CE res0lution of four basic drugs werestudied. The results show that Ds has a different effects on the separation of various drugsbecause of different molecular structures. At D.=0(β-CD), no separation was found for isoproterenol, ofloxacin and propranolol. The resolution of both isoproterenol and ofloxacin in-creased with the increase of Ds, but decreased when Ds was 14. The best reso1uti0n was atDs= 10. 2. The resolution of propranolol increased with increasing Ds. In contrast, the resolution of chlorophiramine decreased with the increase of Ds. The effects of the position ofsubstitution of HP-β-CD on separations were also investigated- The results demonstrate thatthe substitution at the second position of CD plays an important role in the separation ofenantiomers- ln general, the more substitution at the second position of CD, the better theseparation was obtained because the substitution of the second position made the wide open-ing become wider- This probably makes it easier for some molecular to enter the cyclodextrincavity, which c0uld facilitate enantiomeric separation.
