[A silicon phthalocyanine axially substituted by nipagin: synthesis, molecular spectroscopic properties, and in vitro photodynamic activities].

A new silicon phthalocyanine axially substituted by Nipagin, i.e. bis(4-methoxycarboxyl phenoxy)phthalocyaninatosilicon, has been synthesized and characterized by IR, NMR, HPLC and elemental analysis. Its electronic absorption spectra and fluorescence spectra in different solvents were investigated. It was found that the compound existed in the form of monomer in a saline solution containing 2% (phi) Cremophor EL and 20% (phi) propanediol. The electronic absorption spectra of the compound in the above saline solution were typical for non-aggregated phthalocyanines, showing an intense and sharp Q band at 683 nm with a molar absorption coefficient of 7.47 x 10(4) mol(-1) x L x cm(-1). The compound exhibited a relatively strong fluorescence emission at 690 nm with a quantum yield of 0.34 and with a fluorescence lifetime of 4.7 ns. The primary in vitro assay showed the compound had photodynamic killing activities against B16 melanoma cells with a LD50(half lethal dose) of 1.2 x 10(-4) mol x L(-1).