Man-Zhou Zhu

Photoinduced electron-transfer reactions in a host-guest assembly of mono-6-p-nitrobenzoyl-β-cyclodextrin with N-(1-naphthylacetyl)-1-adamantanamine

Photoinduced electron transfer was studied in a supramolecular complex assembled by an electron-donating substrate (N-(1-naphthylacetyl)-1-adamantanamine (1)) and an electron-accepting receptor (p-nitrobenzoyl-β-cyclodextrin (NBCD)), which was stabilized by hydrophobic interactions in water/methanol (9 : 1) binary solvents. Fluorescence quenching results indicated that the electron transfer process occurred in a intra-supramolecular system. The electron transfer reactions of 1- or 2-naphthyl acetate with NBCD were also studied, and upward Stern-Volmer curves were obtained. It is concluded that two different electron transfer pathways, intra-supramolecular and inter-molecular electron transfer processes, exist.

A Synthetic Study of Neutral and Cationic Cholesteryl Derivatives as Gene Vectors

Abstract Some novel neutral and cationic lipids bearing cholesteryl groups were synthesized. These lipids contain ketal units as linker bonds which should be easily biodegradable in cells.

Inclusion complexation of N-substituted phenothiazines and their radical cations generated electrochemically with β-cyclodextrin

The interactions of β-cyclodextrin (β-CD) with N-phenylphenothiazine (1), N-benzylphenothiazine (2) and N-phenethylphenothiazine (3) were studied by cyclic voltammetry. In aqueous solutions, increasing the amount of β-CD caused negative shifts in the anodic peaks and an increase in the current of the 1/1+• and 3/3+• couples owing to the fact that more 1 and 3 were included in the β-CD cavities. However, compound 2 neither gave an anodic nor a cathodic wave in the presence of β-CD because the oxidization reactions on the surface of electrode were controlled by the conformations of the N-substituted phenothiazines in the cavity of β-CD. In 1:9 methanol/water binary solutions, 1 and 3 were investigated by fast scan cyclic voltammetry which showed that the irreversible waves became quasi-reversible waves in the presence of β-CD, confirmed the stabilization of cation radical intermediates by β-CD. The electrochemical and absorption spectral data indicated 1:1 inclusion complex formation of β-CD with 1 and 3 cation radicals in methanol/water binary solutions and the binding constants of 1+• and 3+• were very large under this condition.