Synthesis and structure-mutagenicity relationship of benzo-annulated cyclopentaphenanthrenes

The synthesis of 2,3-dihydro-1H-indeno[5,4-a]anthracene (2), the fluoreno[a ]anthracenes 3 and 4, 2,3-dihydro-1H-cyclopenta[a]chrysene (6), 3,4-dihydro -2-vinylphenanthrene (10) and cyclopenta[c]chrysenes 11, 12 has been descri bed. Structure analysis of the new products by H-1 and C-13 NMR spectroscop y is presented. Estimates of the mutagenic activity of compounds 2-4, 6 and 11-14 in Salmanella typhimurium determined by Ames' test indicate that all products are inactive for both TA 98 and TA 100 strains except 4, 5-dihydr o-3H-cyclopenta [c]chrysene (12). The mutagenic properties of these compoun ds have been compared with those shown by previously studied benzo[g]cyclop enta[a]phenanthrenes and cyclopenta[c]phenanthrenes and discussed. Some con clusions have been drawn about the effects of benzoannulation and of the ca rbonyl function on the mutagenicity of this class of compounds. (C) 2001 El sevier Science Ltd. All rights reserved.