title: [Inclusion of coenzyme Q10 with beta-cyclodextrin studied by polarography].
abstract: OBJECTIVE
  To investigate the inclusion of coenzyme Q10 with beta-cyclodextrin (beta-CD).
  
  
  METHODS
  The inclusion of the electroactive guest molecule coenzyme Q10 with the host molecule beta-CD was studied by the polarography. The change of the reduction peak current of the inclusion complex with time and the change of the peak potential of the inclusion complex with beta-CD concentration were examined. In order to study the photostability, the change of the reduction peak current of both coenzyme Q10 and coenzyme Q10-beta-CD inclusion complex with time were also examined under light, separately.
  
  
  RESULTS
  In 0.1 mol x L(-1) HAc/NaAc (pH 4.7) buffer-ethanol/water (60:40) medium, coenzyme Q10 was included with p-CD to form an 1:1 inclusion complex. The formation constant Kf was 1.26 x 10(4) L x mol(-1) the apparent formation rate constant was 6.64 x 10(-2) min(-1). The photodegradation apparent rate constant of coenzyme Q10 as 7.77 x 10(-3) min(-1) and that of the coenzyme Q10-beta-CD inclusion complex was 3.38 x 10(-3) min(-1).
  
  
  CONCLUSIONS
  The inclusion of coenzyme Q10 with beta-CD took place. The stability of coenzyme Q10 to lights was improved in a certain degree due to the formation of the inclusion complex.
authors.affiliation: Institute of Analytical Science, Northwest University, Xi' an 710069, China.
authors.forename: Hai-ying
authors.initials: HY
authors.lastname: Yang
authors.forename: Jun-feng
authors.initials: JF
authors.lastname: Song
mesh_terms: D003067:Coenzymes / Q000737:chemistry; D004339:Drug Compounding / Q000379:methods; D008027:Light; D010084:Oxidation-Reduction / Q000528:radiation effects; D011048:Polarography / Q000379:methods*; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D003067:Coenzymes; D047392:beta-Cyclodextrins; D014451:Ubiquinone; C024989:coenzyme Q10