Human immunodeficiency virus type I reverse transcriptase (RT) possesses distinct DNA polymerase and RNase H sites, whereas integrase (IN) uses the same active site to perform 3-end processing and strand transfer of the proviral DNA. These four enzymatic activities are essential for viral replication and require metal ions. Two Mg 2؉ ions are present in the RT polymerase site, and one or two Mg 2؉ ions are required for the catalytic activities of RNase H and IN. We tested the possibility of inhibition of the RT polymerase and RNase H as well as the IN 3-end processing and transfer activities of purified enzymes by a series of 3,7-dihydroxytropolones designed to target two Mg 2؉ ions separated by ϳ3.7 Å. The RT polymerase and IN 3 processing and strand transfer activities were inhibited at submicromolar concentrations, while the RNase H activity was inhibited in the low micromolar range. In all cases, the lack of inhibition by tropolones and O-methylated 3,7-dihydroxytropolones was consistent with the active molecules binding the metal ions in the active site. In addition, inhibition of the DNA polymerase activity was shown to depend on the Mg 2؉ concentration. Furthermore, selective inhibitors were identified for several of the activities tested, leaving some potential for design of improved inhibitors. However, all tested compounds exhibited cellular toxicity that presently limits their applications.

The complexes between methyllithium and chiral 3-aminopyrrolidine (3-AP) lithium amides bearing a second asymmetric center on their lateral amino group were studied using multinuclear ((1)H, (6)Li, (13)C, (15)N) low-temperature NMR spectroscopies in tetrahydrofuran-d(8). The results indicate that lithium chelation forces the pyrrolidine ring of the 3-AP to adopt a norbornyl-like conformation and that robust 1:1 noncovalent complexes between methyllithium and 3-AP lithium amides form in the medium. A set of (1)H-(1)H and (1)H-(6)Li NMR cross-coupling correlations shows that the binding of methyllithium can take place along the "exo" or the "endo" face of this puckered structure, depending on the relative configuration of the lateral chiral group. This aggregation step renders the nitrogen of the 3-amino group chiral, the "exo" and "endo" topologies corresponding to the (S) and (R) configurations, respectively, of this atom. Density functional theory calculations show that the "exo" and "endo" arrangements are, for both diastereomers, almost isoenergetic even when solvent is taken into account. This result suggests that the formation of the mixed aggregates is under strict kinetic control. A relationship between the topology of these complexes and the sense of induction in the enantioselective alkylation of aromatic aldehydes by alkyllithiums is proposed.