Human neuraminidases (NEU) are associated with human diseases including cancer, atherosclerosis, and diabetes. To obtain small molecule inhibitors as research tools for the study of their biological functions, we designed a library of 2-deoxy-2,3-didehydro- N-acetylneuraminic acid (DANA) analogues with modifications at C4 and C9 positions. This library allowed us to discover selective inhibitors targeting the human NEU3 isoenzyme. Our most selective inhibitor for NEU3 has a K of 320 ± 40 nM and a 15-fold selectivity over other human neuraminidase isoenzymes. This inhibitor blocks glycolipid processing by NEU3 in vitro. To improve their pharmacokinetic properties, various esters of the best inhibitors were synthesized and evaluated. Finally, we confirmed that our best compounds exhibited selective inhibition of NEU orthologues from murine brain.

There is an unmet need to discover and develop novel antischistosomal drugs. As exemplified by MMV665852, N,N=-diarylureas have recently emerged as a promising antischistosomal chemotype. In this study, we evaluated the structure-activity relationships of 46 commercially available analogs of MMV665852 on newly transformed schistosomula (NTS) and adult Schistosoma mansoni worms in vitro. Active compounds were evaluated with a cytotoxicity assay, in silico calculations, metabolic stability studies, and an in vivo assay with mice harboring adult S. mansoni worms. Of the 46 compounds tested at 33.3 M, 13 and 14 compounds killed NTS and adult worms, respectively, within 72 h. Nine compounds had 90% inhibitory concentrations (IC 90 s) of <10 M against adult worms, with selectivity indexes of >2.8. Their physicochemical properties and permeation through an artificial membrane indicated good to moderate intestinal absorption. Their metabolic stabilities ranged from low to high. Despite satisfactory in vitro results and in silico predictions, only one compound resulted in a statistically significant worm burden reduction (66%) after administration of a single oral dose of 400 mg/kg of body weight to S. mansoni-infected mice. Worm burden reductions of 0 to 43% were observed for the remaining eight compounds tested. In conclusion, several analogs of the N,N=-diarylurea MMV665852 had high efficacy against S. mansoni in vitro and favorable physicochemical properties for permeation through the intestinal wall. To counteract the low efficacy observed in the mouse model, further investigations should focus on identifying compounds with improved solubility and pharmacokinetic properties.

Antimicrobial resistance has become a serious concern for the treatment of urinary tract infections. In this context, an anti‐adhesive approach targeting FimH, a bacterial lectin enabling the attachment of E. coli to host cells, has attracted considerable interest. FimH can adopt a low/medium‐affinity state in the absence and a high‐affinity state in the presence of shear forces. Until recently, mostly the high‐affinity state has been investigated, despite the fact that a therapeutic antagonist should bind predominantly to the low‐affinity state. In this communication, we demonstrate that fluorination of biphenyl α‐d‐mannosides leads to compounds with perfect π–π stacking interactions with the tyrosine gate of FimH, yielding low nanomolar to sub‐nanomolar KD values for the low‐ and high‐affinity states, respectively. The face‐to‐face alignment of the perfluorinated biphenyl group of FimH ligands and Tyr48 was confirmed by crystal structures as well as 1H,15N‐HSQC NMR analysis. Finally, fluorination improves pharmacokinetic parameters predictive for oral availability.

Despite the rapidly increasing number of patients suffering from type 2 diabetes, Alzheimer's disease, and diabetesinduced dementia, there are no disease-modifying therapies able to prevent or block disease progress. In this work, we investigate the potential of nature-inspired glucosylpolyphenols against relevant targets, including islet amyloid polypeptide, glucosidases and cholinesterases. Moreover, with the premise of Fyn kinase as a paradigm-shifting target in Alzheimer's drug discovery, we explore glucosylpolyphenols as blockers of Aβ-induced Fyn kinase activation, while looking into downstream effects leading to Tau hyperphosphorylation. Several compounds inhibit Aβ-induced Fyn kinase activation and decrease pTau levels at 10 μM concentration, particularly the per-O-methylated glucosylacetophloroglucinol and the 4-glucosylcatechol dibenzoate, the latter inhibiting also butyrylcholinesterase and -glucosidase. Both compounds are non-toxic with ideal pharmacokinetic properties for further development. This work ultimately highlights the multitarget nature, fine structural tuning capacity and valuable therapeutic significance of glucosylpolyphenols in the context of these metabolic and neurodegenerative disorders.

With the lack of available drugs able to prevent the progression of Alzheimer’s disease (AD), the discovery of new neuroprotective treatments able to rescue neurons from cell injury is presently a matter of extreme importance and urgency. Here, we were inspired by the widely reported potential of natural flavonoids to build a library of novel flavones, chromen-4-ones and their C-glucosyl derivatives, and to explore their ability as neuroprotective agents with suitable pharmacokinetic profiles. All compounds were firstly evaluated in a parallel artificial membrane permeability assay (PAMPA) to assess their effective permeability across biological membranes, namely the blood-brain barrier (BBB). With this test, we aimed not only at assessing if our candidates would be well-distributed, but also at rationalizing the influence of the sugar moiety on the physicochemical properties. To complement our analysis, logD7.4 was determined. From all screened compounds, the p-morpholinyl flavones stood out for their ability to fully rescue SH-SY5Y human neuroblastoma cells against both H2O2- and Aβ1-42-induced cell death. Cholinesterase inhibition was also evaluated, and modest inhibitory activities were found. This work highlights the potential of C-glucosylflavones as neuroprotective agents, and presents the p-morpholinyl C-glucosylflavone 37, which did not show any cytotoxicity towards HepG2 and Caco-2 cells at 100 μM, as a new lead structure for further development against AD.