BACTERIAL MUTAGENICITY OF DICYCLOPENTA-FUSED PYRENE CONGENERS IN FVT-PYROLYSATES: PARTIAL COMBUSTION EXHAUST MIMICS

Abstract

The mutagenicity response of well-characterized flash vacuum thermolysis (FVT) pyrolysates that contain cyclopenta[cd]pyrene (1) and 1-ethynylpyrene (1b) (pyrolysate I), the dicyclopentapyrene congeners dicyclopenta[cd,mn]- (2), dicyclopenta[cd,fg]- (3), or dicyclopenta[cd,jk]pyrene (4) and their related bis-ethynyl- (2b–4b) and monocyclopenta-ethynylpyrene (2a–4a) analogues (pyrolysates II–IV, respectively), or cyclopenta[cd]- (1) and the three dicyclopentapyrenes (2–4) (pyrolysate V), respectively, was assessed using the standard protocol outlined by Ames et al. (Salmonella typhimurium strain TA98 ± S9-mix 4% (v/v)). It is shown that the mutagenic activity of the pyrolysates deviates from the weighed sum of the activity of the individual pyrolysate constituents. Hence, FVT-pyrolysates are proposed as model mixtures, that is, as partial combustion exhaust mimics, to establish and evaluate interactions (additive, synergistic, or antagonistic effects) that may occur among the constituents and affect the global mutagenicity response.

Keywords:

• Ames assay
• combustion exhausts mimics
• dicyclopenta-fused pyrenes
• ethynyl-PAH
• flash vacuum thermolysis (FVT)
• strain TA98

Acknowledgments

Financial support from the Gobierno Vasco (Beca para la Formación de Investigadores) for M. J. Otero Lobato is gratefully acknowledged.

Notes

^a His revertants/nmol was calculated by least squares regression from the initial ascending linear portion of the dose response curve (Figure 1). Correlation coefficients (r ²) were > 0.95, except for pyrolysate II-S9-mix (r ² 0.71).

^b Between parentheses the expected specific mutagenic activity calculated from the weighed contributions of the major components cyclopenta[cd]- (1), dicyclopenta[cd,mn]- (2), dicyclopenta[cd, fg]- (3), and dicyclopenta[cd, jk]pyrene (4) is reported.