Complexation of bis(morpholyldithiocarbamato)copper(II), a superoxide scavenger, in β-cyclodextrins

Bis(morpholyldithiocarbamato)copper(II), Cu(MorDTC)₂, has been studied as a scavenger of the superoxide anion, a reactive radical that can cause very negative effects in vivo. The scavenging takes place through a superoxide dismutase (SOD)-like process. The copper(II) compound has a poor solubility in water. The interaction of Cu(MorDTC)₂ with β-cyclodextrin (β-CD) and its dimethyl derivative (dmβ-CD) was studied, resulting in an increase by one order in water solubility and the SOD-like activity of Cu(MorDTC)₂. The inclusion constants were determined spectrophotometrically at 435 nm and 300 K. For β-CD, the values of log K₁₁ = 3.96 (± 0.01) and log K₂₁ = 7.47 (± 0.04) were obtained. With dmβ-CD, log K₁₁ = 3.73 (± 0.08) and log K₂₁ = 6.30 (± 0.01) were the values achieved.