Discovery of Novel Chemical Series of OXA-48 beta-Lactamase Inhibitors by High-Throughput Screening.
Garofalo, B., Prati, F., Buonfiglio, R., Coletta, I., D'Atanasio, N., Molteni, A., Carettoni, D., Wanke, V., Pochetti, G., Montanari, R., Capelli, D., Milanese, C., Di Giorgio, F.P., Ombrato, R.(2021) Pharmaceuticals (Basel) 14
- PubMed: 34202402 
- DOI: https://doi.org/10.3390/ph14070612
- Primary Citation of Related Structures:  
7AUX, 7AW5 - PubMed Abstract: 
The major cause of bacterial resistance to β-lactams is the production of hydrolytic β-lactamase enzymes. Nowadays, the combination of β-lactam antibiotics with β-lactamase inhibitors (BLIs) is the main strategy for overcoming such issues. Nevertheless, particularly challenging β-lactamases, such as OXA-48, pose the need for novel and effective treatments. Herein, we describe the screening of a proprietary compound collection against Klebsiella pneumoniae OXA-48, leading to the identification of several chemotypes, like the 4-ideneamino-4H-1,2,4-triazole (SC_2) and pyrazolo[3,4-b]pyridine (SC_7) cores as potential inhibitors. Importantly, the most potent representative of the latter series (ID2, AC 50 = 0.99 μM) inhibited OXA-48 via a reversible and competitive mechanism of action, as demonstrated by biochemical and X-ray studies; furthermore, it slightly improved imipenem's activity in Escherichia coli ATCC BAA-2523 β-lactam resistant strain. Also, ID2 showed good solubility and no sign of toxicity up to the highest tested concentration, resulting in a promising starting point for further optimization programs toward novel and effective non-β-lactam BLIs.
Organizational Affiliation: 
Angelini Pharma S.p.A., Global R&D External Innovation, Viale Amelia 70, 00181 Rome, Italy.