Photokilling Squamous Carcinoma Cells SCCVII with Ultrafine Particles of Selected Metal Oxides

The ability of ultrafine particles of TiO₂, WO₃ and iron-doped TiO₂ to kill cancer cells in the presence of UV irradiation was investigated. The best photokilling effect on carcinoma cells SCVII cultured in vitro showed iron-doped TiO₂ ultrafine particles synthesized by the sol-gel procedure with starting chemicals Ti(IV)-isopropoxide and anhydrous Fe(II)-acetate. It was found that a small particle size and high dispersity influenced citotoxicity and photocatalytic efficiency. The remarkable photokiling effect of highly iron-doped TiO₂ ultrafine particles (the molar ratio Fe/Ti = 0.136) in the presence of UV irradiation was observed. The influence of ultrafine metal oxide particles on the inhibition of cancer cell proliferation was measured using a ³H-thymidine incorporation test. The possible mechanism involved in the photokilling of carcinoma cells with ultrafine particles of selected metal oxides was discussed.     

Synthesis of marine alkaloids leucettamines B and C by β-lactam ring rearrangement

A new method for the synthesis of marine alkaloids leucettamines B and C from Leucetta sp. sponges is described. The key step is the base-promoted rearrangement of β-lactam into imidazolone ring. Leucettamines B and C as well as their N-benzoyl derivatives were obtained in high yields. Single-crystal structures of both leucettamines B and C were determined by X-ray diffraction confirming Z-configuration of double bond at 4-position of imidazolone.