Inclusion of coenzyme Q₁₀ with β-cyclodextrin studied by polarography

AimTo investigate the inclusion of coenzyme Q₁₀ with β-cyclodextrin (β-CD). Methods The inclusion of the electroactive guest molecule coenzyme Q₁₀ with the host molecule β-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 β-CD concentration were examined. In order to study the photostability, the change of the reduction peak current of both coenzyme Q₁₀ and coenzyme Q₁₀-β-CD inclusion complex with time were also examined under light, separately. ResultsIn 0.1 mol·L^-1 HAc/NaAc (pH 4.7) buffer-ethanol/water (60∶40) medium, coenzyme Q₁₀ was included with β-CD to form an 1∶1 inclusion complex. The formation constant k_f was 1.26×10⁴ L·mol^-1, the apparent formation rate constant was 6.64×10^-2 min^-1. The photodegradation apparent rate constant of coenzyme Q₁₀ was 7.77×10^-3 min^-1, and that of the coenzyme Q₁₀-β-CD inclusion complex was 3.38×10^-3 min^-1. ConclusionThe inclusion of coenzyme Q₁₀ with β-CD took place. The stability of coenzyme Q₁₀ to lights was improved in a certain degree due to the formation of the inclusion complex.