[1] KIT, Inst Organ Chem, D-76131 Karlsruhe, Germany
[2] Clariant Prod Deutsch GmbH, Clariant Innovat Ctr, Grp Technol & Innovat, Grp Chem Res,Competence Ctr Colorants & Funct Che, D-65296 Frankfurt, Germany
[3] Inst Toxicol & Genet, D-76344 Eggenstein Leopoldshafen, Germany