Six derivatives of trans-4-aminostilbene bearing different alkyl groups in the 4′-position and six of the corresponding nitro compounds were synthesized and tested for their mutagenic potency in Salmonellatyphimurium strains TA98 and TA100. Regarding the test series in presence of S9-mix, maximum activity was observed for those trans-4- aminostilbenes and trans-4-nitrostilbenes bearing small alkyl substituents like methyl and ...