1-[2-(Diarylmethoxy)ethyl]-2-methyl-5-nitroimidazoles (DAMNIs) is a novel family of HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) active at submicromolar concentration. Replacement of one phenyl ring of 1-[2-(diphenylmethoxy)ethyl]-2-methyl-5-nitroimidazole (4) with heterocyclic rings, such as 2-thienyl or 3-pyridinyl, led to novel DAMNIs with increased activity. In HIV-1 WT cell-based assay the racemic 1-{2-[alpha-(thiophen-2-yl)phenylmethoxy]ethyl}-2-methyl-5-nitroimidazole (7) (EC(50) = 0.03 microM) proved 5 times more active than compound 4. Docking experiments showed that the introduction of a chiral center would not affect the binding of both (R)-7 and (S)-7. The internal scoring function of the Autodock program calculated the same inhibition constant (K(i) = 7.9 nM) for the two enantiomers. Compounds 7 (ID(50) = 8.25 microM) were found more active than efavirenz (ID(50) = 25 microM) against the viral RT carrying the K103N mutation, suggesting for these compounds a potential use in efavirenz based anti-AIDS regimens.