Study of Carcinogenic Mechanism for Polycyclic Aromatic Hydrocarbons: Extended Bay Region Theory and Its Quantitative Model
The author suggests the concept of an extended bay region and thinks that the essential agent of carcinogenesis for polycyclic aromatic hydrocarbons (PAH) should be, as a rule, the highest delocalization energy (β unit) of carbonium ion at the aromatic angular ring (A region), which is obtained by the perturbational molecular orbit (PMO) method. The carcinogenic activity exhibited by a PAH is determined by the competition between the carcinogenesis and detoxification, in which it participates. The detoxificative efficacy of each kind of the hinder carcinogenic factors has been evaluated, including the biologic factor B and three structural factors of PAH’s molecule: K, A and L. After making necessary approximations, K = 0.228, A = 0.5, L = 1.22 and B = 0.7 are obtained. This paper also suggests a concept of a carcinogenic constant. For the PAH with the same N, which is the number of aromatic rings, C is a constant. The relationship between C and N is called the “Pyramid Regulation”.