Two kinds of β-cyclodextrin (β-CD) derivatives mono-6-(N-histamino)-6-deoxy-β-cyclodextrin (6-His-β-CD) and mono-2-(N-histamino)-2-deoxy-β-cyclodextrin (2-His-β-CD) were prepared by reacting β-CD withp-toluene sulfonyl chloride

displacement the monotosylate with iodide

and finally the reaction of cyclodextrin iodide with nucleophile L-histidine.From these derivatives

the β-CD-Cu(Ⅱ) complexes (Cu(Ⅱ)/6-His-β-CD， Cu(Ⅱ)/2-His-β-CD) with polyphenol oxidase (PPO) activity were synthesized.The derivatives and the complexes were characterized with elemental analysis

Fourier-transform infrared spectroscopy

nuclear magnetic resonance spectroscopy and atomic absorption spectrometry.The complexes were used as catalysts for the oxidation of catechol using O2 as the oxidant

which was monitored by UV-Vis spectrophotometer.The effects of temperature and pH value on the reaction were also studied.The results indicated that the PPO mimics exhibited high catalytic activities.Cu(Ⅱ)/2-His-β-CD showed higher PPO activity than Cu(Ⅱ)/6-His-β-CD.The kinetic studies showed that all three factors

the hydrophobic environment provided by β-CD

the Cu(Ⅱ) bound to the histamine and the base catalysis contributed to the PPO activity.