RESUMO
Further investigations towards novel glycopeptide/beta-lactam heterodimers are reported. Employing a multivalent approach to drug discovery, vancomycin and cephalosporin synthons, 4, 2, 5 and 10, 18, 25 respectively, were chemically linked to yield heterodimer antibiotics. These novel compounds were designed to inhibit Gram-positive bacterial cell wall biosynthesis by simultaneously targeting the principal cellular targets of both glycopeptides and beta-lactams. The positional attachment of both the vancomycin and the cephalosporin central cores has been explored and the SAR is reported. This novel class of bifunctional antibiotics 28-36 all displayed remarkable potency against a wide range of Gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA). A subset of compounds, 29, 31 and 35 demonstrated excellent bactericidal activity against MRSA (ATCC 33591) and 31 and 35 also exhibited superb in vivo efficacy in a mouse model of MRSA infection. As a result of this work compound 35 was selected as a clinical candidate, TD-1792.
Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Cefalosporinas/síntese química , Cefalosporinas/farmacologia , Descoberta de Drogas/métodos , Glicopeptídeos/síntese química , Glicopeptídeos/farmacologia , beta-Lactamas/síntese química , beta-Lactamas/farmacologia , Animais , Antibacterianos/química , Cefalosporinas/química , Dimerização , Desenho de Fármacos , Feminino , Glicopeptídeos/química , Bactérias Gram-Positivas/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Molecular , beta-Lactamas/químicaRESUMO
Novel derivatives of N-decylaminoethylvancomycin (2), containing appended hydrophilic groups were synthesized and their antibacterial activity and ADME properties were evaluated. The compounds were prepared by reacting amines with the C-terminus (C-) of 2 using PyBOP mediated amide formation, or with the resorcinol-like (R-) position of 2 using a Mannich aminomethylation reaction. These analogs retained the antibacterial activity of 2 against methicillin-resistant staphylococci and vancomycin-resistant enterococci. Compounds with a negatively charged auxiliary group also exhibited improved ADME properties relative to 2. In particular, R-phosphonomethylaminomethyl derivative 21 displayed good in vitro antibacterial activity, high urinary recovery and low distribution to liver and kidney tissues. Based on these results, 21 was advanced into development as TD-6424, and is currently in human clinical trials. The generic name telavancin has recently been approved for compound 21.
