Investigation on the antioxidation of the flavonoids based on the photoinduced chemiluminescence of lucigenin by a new Zinc(II) phthalocyanine compound.

A zinc(II) phthalocyanine compound, tetra-alpha-(2,2,4-tirmethyl-3-pentoxy) Phthalocyanine Zinc (ZnPc(OR)(4)) was synthesized in this paper and this zinc (II) phthalocyanine compound was used as the photosensitizer in the photoinduced chemiluminescence (PCL) of lucigenin in N,N-dimethylformamide (DMF). The photoexcited ZnPc(OR)(4) would produce singlet molecular oxygen ((1)O(2)), which would further react with DMF to form corresponding DMF radicals, such as CH(3) and CH(2)N(CH(3))CHO, or corresponding alkylperoxyl radicals. Then the carbon centred radical would react with lucigenin to initiate the chemiluminescence. These results would provide useful data to establish a method for evaluation of the ability of (1)O(2) generation of phthalocyanine. It was also found in this paper that the flavonoids could effectively inhibit this PCL system, which parallelled very well to flavonoids' radical-scavenging capacity. The mechanism of this PCL system and the relationship between the molecular structure of flavonoids and their radical-scavenging activity are also discussed in detail in this paper.