Serena Massari

Influenza viruses remain a major global health threat due to their rapid evolution and ability to evade current therapies. Among viral targets, the PA–PB1 interface of the RNA polymerase complex has emerged as an attractive site for small‐molecule inhibition. Based on compound 1 , a previously identified PA–PB1 interaction inhibitor featuring a cycloheptathiophene‐3‐carboxamide scaffold, we designed and synthesized a new series of derivatives to investigate the role of the cycloheptyl moiety in antiviral activity and water solubility. In parallel, we developed an improved three‐step synthetic route to access 2‐amidothiophene‐3‐carboxamide analogs more efficiently. The new derivatives ( 2–16 ) provided valuable structure–activity relationship insights, highlighting how modifications at C‐5 influence both anti‐influenza potency and solubility. Among them, the C‐5 phenyl analog 9 displayed the strongest antiviral activity, achieving sub‐micromolar EC ₅₀ values (0.19–1.11 µM) across a panel of influenza strains, along with a CC ₅₀ value > 100 µM. Notably, the C‐5 methyl analog 5 showed the greatest enhancement in aqueous solubility (75.2 µM) while maintaining low‐micromolar potency (EC ₅₀ of 2 µM) and no significant toxicity (CC ₅₀ > 100 µM). Despite structural divergence from the starting hit 1 , both compounds preserved the PA–PB1 interaction inhibition mechanism, as demonstrated by enzyme‐linked immunosorbent assay (ELISA) and supported by docking studies within the PA _C cavity.

Dengue virus (DENV) remains a major global health concern without effective treatments. Previously, we identified sulfonyl anthranilic acid (SAA) derivatives (compounds 1 and 2) as potent pan-DENV inhibitors, likely targeting a primate-specific factor. Here, mass spectrometry-based target deconvolution revealed that SAA compounds downregulate ribosomal protein expression, some of which are essential for DENV replication, as confirmed by siRNA-knockdown studies. This novel mechanism aligns with the broad-spectrum antiviral activity of compounds 1 and 2. Moreover, compound 1 was also effective against the Zika virus in a human brain organoid model. The subsequent medicinal chemistry optimization process resulted in the identification of compound 7, which demonstrated an EC₅₀ value of 50 nM against DENV-2, promising broad-spectrum potential and favorable in vitro ADME properties. Further studies indicated that these compounds modulate the 5'-terminal oligopyrimidine (5'-TOP) motif in ribosomal mRNAs. These findings open a new avenue for antiviral development by targeting a previously unexplored host pathway.

Antimicrobial resistance (AMR) represents a significant global concern, driven by the overuse of antibiotics. One of the principal mechanisms contributing to AMR is the activity of microbial efflux pumps (EPs), which expel diverse antibiotics out of bacterial cells, thereby rendering them ineffective. Our research aimed to expand the range of molecular classes that inhibit the Staphylococcus aureus EP NorA. In this study, starting from the hit compound pyrazolo[4,3‐c][1,2]benzothiazine 5,5‐dioxide 1, previously reported as a NorA efflux pump inhibitor (EPI), we undertook medicinal chemistry efforts, which involved the iterative combination of the design and synthesis of new analogues with data obtained through ethidium bromide efflux inhibition assays. Subsequent synergistic assays with ciprofloxacin (CPX) against the resistant strain SA‐1199B led to the identification of three potent compounds (3, 10, and 19). The evaluation of these compounds in combination with CPX against NorA‐overexpressing and NorA‐knockout strains (SA‐K2378 and SA‐K1902, respectively) confirmed that the observed synergy with CPX is dependent on the presence of NorA. Additionally, the combination of NorA EPIs with CPX reduced biofilm production in NorA‐overexpressing strains. These findings enhance our understanding of the structure–activity relationship of pyrazolobenzothiazine derivatives and support the use of EtBr efflux assays for rapid NorA inhibitors' identification.

Dengue virus (DENV) serotypes 1–4 are mosquito‐borne flaviviruses that are responsible for significant morbidity and mortality worldwide, particularly in tropical and subtropical regions. Although two vaccines have been approved, their unbalanced efficacy across serotypes poses potential risks for specific populations. There are currently no approved antiviral treatments for DENV, resulting in a clear medical need, especially in endemic countries. Herein, a medicinal chemistry optimization of the pyridobenzothiazolone (PBTZ) derivative 2 is conducted, which results in the synthesis of a new series of PBTZ analogues. Compounds 15 and 19 exhibit nanomolar EC₅₀ values against all four DENV serotypes. While new PBTZ analogues do not inhibit DENV polymerase as the first series of PBTZ analogues do, they display anti‐DENV activity across all time points during time‐of‐addition assays and demonstrate the capacity to influence the infectivity of newly produced virions without affecting viral RNA synthesis. Compound 19 exhibits an EC₅₀ of 50 nM against DENV‐2 and a selectivity index of >2074, representing the most potent PBTZ analogue reported to date, with a significant improvement of over 30‐fold compared to the initial hit 2. In vitro pharmacokinetic studies conducted on compound 19 disclose a promising profile, but with still some suboptimal values.

MicroRNAs (miRNAs) play a crucial role in ovarian cancer (OC) pathogenesis and miRNA processing can be the object of pharmacological intervention. By exploiting our in-house quinolone library, we combined a cell-based screening with medicinal chemistry efforts, ultimately leading to derivative 33 with anti-OC activity against distinct cell lines (GI₅₀ values 13.52–31.04 μM) and CC_{50 Wi-38} = 142.9 μM. Compound 33 retained anticancer activity against additional cancer cells and demonstrated a synergistic effect with cisplatin against cisplatin-resistant A2780 cells. Compound 33 bound TRBP by SPR (K_D = 4.09 μM) and thermal shift assays and its activity was TRBP-dependent, leading to modulation of siRNA and miRNA maturation. Derivative 33 exhibited augmented potency against OC cells and a stronger binding affinity for TRBP compared to enoxacin, the sole quinolone identified as a modulator of miRNA maturation. Consequently, 33 represents a promising template for developing novel anti-OC agents with a distinctive mechanism of action.

Facile procedures exploiting three-component reactions were developed to regioselectively obtain 2-amino-7-methyl-5-phenyl- and 2-amino-5-methyl-7-phenyl-[1,2,4]triazolo[1,5-a]pyrimidine analogues bearing a C-6 electron withdrawing group.

Synthetic lethality (SL) is an innovative strategy in targeted anticancer therapy that exploits tumor genetic vulnerabilities. This topic has come to the forefront in recent years, as witnessed by the increased number of publications since 2007. The first proof of concept for the effectiveness of SL was provided by the approval of poly(ADP-ribose)polymerase inhibitors, which exploit a SL interaction in BRCA-deficient cells, although their use is limited by resistance. Searching for additional SL interactions involving BRCA mutations, the DNA polymerase theta (POLθ) emerged as an exciting target. This review summarizes, for the first time, the POLθ polymerase and helicase inhibitors reported to date. Compounds are described focusing on chemical structure and biological activity. With the aim to enable further drug discovery efforts in interrogating POLθ as a target, we propose a plausible pharmacophore model for POLθ-pol inhibitors and provide a structural analysis of the known POLθ ligand binding sites.

We report [1,2,4]triazolo[3,4-b]benzothiazole (TBT) as a new inhibitor scaffold, which competes with nicotinamide in the binding pocket of human poly- and mono-ADP-ribosylating enzymes. The binding mode was studied through analogues and cocrystal structures with TNKS2, PARP2, PARP14, and PARP15. Based on the substitution pattern, we were able to identify 3-amino derivatives 21 (OUL243) and 27 (OUL232) as inhibitors of mono-ARTs PARP7, PARP10, PARP11, PARP12, PARP14, and PARP15 at nM potencies, with 27 being the most potent PARP10 inhibitor described to date (IC₅₀ of 7.8 nM) and the first PARP12 inhibitor ever reported. On the contrary, hydroxy derivative 16 (OUL245) inhibits poly-ARTs with a selectivity toward PARP2. The scaffold does not possess inherent cell toxicity, and the inhibitors can enter cells and engage with the target protein. This, together with favorable ADME properties, demonstrates the potential of TBT scaffold for future drug development efforts toward selective inhibitors against specific enzymes.

The recent increase of bioactivity data freely available to the scientific community and stored as activity data points in chemogenomic repositories provides a huge amount of ready-to-use information to support the development of predictive models. However, the benefits provided by the availability of such a vast amount of accessible information are strongly counteracted by the lack of uniformity and consistency of data from multiple sources, requiring a process of integration and harmonization. While different automated pipelines for processing and assessing chemical data have emerged in the last years, the curation of bioactivity data points is a less investigated topic, with useful concepts provided but no tangible tools available. In this context, the present work represents a first step toward the filling of this gap, by providing a tool to meet the needs of end-user in building proprietary high-quality data sets for further studies. Specifically, we herein describe Q-raKtion, a systematic, semiautomated, flexible, and, above all, customizable KNIME workflow that effectively aggregates information on biological activities of compounds retrieved by two of the most comprehensive and widely used repositories, PubChem and ChEMBL.