Tania Silva

Discovery and optimization of pyridazinone non-nucleoside inhibitors of HIV-1 reverse transcriptase.

A series of benzyl pyridazinones were evaluated as HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs). Several members of this series showed good activity against the wild-type virus and NNRTI-resistant viruses. The binding of inhibitor 5a to HIV-RT was analyzed by surface plasmon resonance spectroscopy. Pharmacokinetic studies of 5a in rat and dog demonstrated that this compound has good oral bioavailability in animal species. The crystal structure of a complex between HIV-RT and inhibitor 4c is also described.

Development of amino-pyrimidine inhibitors of c-Jun N-terminal kinase (JNK): kinase profiling guided optimization of a 1,2,3-benzotriazole lead.

A series of amino-pyrimidines was developed based upon an initial kinase cross-screening hit from a CDK2 program. Kinase profiling and structure-based drug design guided the optimization from the initial 1,2,3-benzotriazole hit to a potent and selective JNK inhibitor, compound 24f (JNK1 and 2 IC(50)=16 and 66 nM, respectively), with bioavailability in rats and suitable for further in vivo pharmacological evaluation.

Development of indole/indazole-aminopyrimidines as inhibitors of c-Jun N-terminal kinase (JNK): optimization for JNK potency and physicochemical properties.

A novel series of indole/indazole-aminopyrimidines was designed and synthesized with an aim to achieve optimal potency and selectivity for the c-Jun kinase family or JNKs. Structure guided design was used to optimize the series resulting in a significant potency improvement. The best compound (17) has IC50 of 3 nM for JNK1 and 20 nM for JNK2, with greater than 40-fold selectivity against other kinases with good physicochemical and pharmacokinetic properties.

Orally bioavailable prodrugs of a BCS class 2 molecule, an inhibitor of HIV-1 reverse transcriptase

The N-2 position of pyridazinone 1, a potent HIV-1 NNRTI that has limited aqueous solubility, was derivatized into a series of hydroxymethyl esters and carbonates as well as one phosphate. The derivatives served as prodrugs to effectively deliver 1 to rat plasma upon oral treatment at 50 mpk. Increases of 4.3- to 8.6-fold in 24-hour exposure of 1 (over that of parent) were observed while the prodrugs and the hydroxymethyl adduct 2 were undetectable.