Synthesis and Density Functional Theory (DFT) Calculation of Haptens for PAHs

Five PAHs haptens 3a similar to 3e were synthesized from naphthalene, anthracene, chrysene, pyrene and acenaphthene via two steps including Friedel-Crafts acylation and Wolff-Kishner-Huang reduction. The sixth hapten 4-(acenaphthylen-3-yl)butanoic acid (3f) was prepared from hapten 3e via three steps including esterification, bromination and elimination. Their structures were confirmed by melting point, H-1 NMR and C-13 NMR. Their optical properties and crystal structures were also investigated. The results of density functional theory (DFT) calculation provided the supports that the size, shape (geometry) and electronic properties at the corresponding parts of 3a similar to 3f did not change significantly, compared to those of PAHs. The haptens 3a similar to 3f were coupled with bovine serum albumin (BSA) to make antigens. The coupling ratios were 1:20 similar to 1:38. These results show that the haptens could be used to induce specific antibodies for PAHs.