RÉSUMÉ
This work relates to the design and synthesis of a series of novel multi-target directed ligands (MTDLs), i.e., compounds 4a-l, via a convenient one-pot three-component Hantzsch reaction. This approach targeted calcium channel antagonism, antioxidant capacity, cathepsin S inhibition, and interference with Nrf2 transcriptional activation. Of these MTDLs, 4i emerged as a promising compound, demonstrating robust antioxidant activity, the ability to activate Nrf2-ARE pathways, as well as calcium channel blockade and cathepsin S inhibition. Dihydropyridine 4i represents the first example of an MTDL that combines these biological activities.
RÉSUMÉ
The bile acid pool has a profound impact on human health and disease. The intestinal microbiota initiates the metabolism of conjugated bile acids through a critical first step catalyzed by bacterial bile salt hydrolase (BSH) and provides unique contributions to the diversity of bile acids. There has been great interest in surveying BSH activity. We compared two substrates with either 2-(7-amino-4-methyl-coumarinyl)acetic acid or 7-amino-4-methyl-coumarin as fluorescent reporters of BSH activity. The BSH-catalyzed conversion of the natural substrate taurocholic acid was followed through an HPLC-based assay by applying 7-nitrobenzo[c][1,2,5]oxadiazole as scavenger for taurine, released in the enzymatic reaction. Hence, a new opportunity to monitor the activity of bile salt hydrolases was introduced.
Sujet(s)
Clostridium perfringens , Colorants fluorescents , Humains , Amidohydrolases/métabolisme , Bactéries/métabolisme , Acides et sels biliairesRÉSUMÉ
The multifactorial nature of Alzheimer's disease necessitates the development of agents able to interfere with different relevant targets. A series of 22 tailored chromanones was conceptualized, synthesized, and subjected to biological evaluation. We identified one representative bearing a linker-connected azepane moiety (compound 19) with balanced pharmacological properties. Compound 19 exhibited inhibitory activities against human acetyl-, butyrylcholinesterase and monoamine oxidase-B, as well as high affinity to both the σ1 and σ2 receptors. Our study provides a framework for the development of further chromanone-based multineurotarget agents.
RÉSUMÉ
Rhodesain is the major cysteine protease of the protozoan parasite Trypanosoma brucei and a therapeutic target for sleeping sickness, a fatal neglected tropical disease. We designed, synthesized and characterized a bimodal activity-based probe that binds to and inactivates rhodesain. This probe exhibited an irreversible mode of action and extraordinary potency for the target protease with a kinac /Ki value of 37,000â M-1 s-1 . Two reporter tags, a fluorescent coumarin moiety and a biotin affinity label, were incorporated into the probe and enabled highly sensitive detection of rhodesain in a complex proteome by in-gel fluorescence and on-blot chemiluminescence. Furthermore, the probe was employed for microseparation and quantification of rhodesain and for inhibitor screening using a competition assay. The developed bimodal rhodesain probe represents a new proteomic tool for studying Trypanosoma pathobiochemistry and antitrypanosomal drug discovery.
Sujet(s)
Cysteine proteases , Trypanosoma brucei brucei , Trypanosoma , Biotine , Fluorescence , Protéomique , Relation structure-activitéRÉSUMÉ
Naturally occurring compounds represent a vast pool of pharmacologically active entities. One of such compounds is andrographolide, which is endowed with many beneficial properties, including the activity against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). To initiate a drug repurposing or hit optimization campaign, it is imperative to unravel the primary mechanism(s) of the antiviral action of andrographolide. Here, we showed by means of a reporter gene assay that andrographolide exerts its anti-SARS-CoV-2 effects by inhibiting the interaction between Kelch-like ECH-associated protein 1 (KEAP1) and nuclear factor erythroid 2-related factor 2 (NRF2) causing NRF2 upregulation. Moreover, we demonstrated that subtle structural modifications of andrographolide could lead to derivatives with stronger on-target activities and improved physicochemical properties. Our results indicate that further optimization of this structural class is warranted to develop novel COVID-19 therapies.
Sujet(s)
Antiviraux/composition chimique , Antiviraux/pharmacologie , Diterpènes/composition chimique , SARS-CoV-2/effets des médicaments et des substances chimiques , Animaux , COVID-19/virologie , Lignée cellulaire , Chlorocebus aethiops , Humains , Protéine-1 de type kelch associée à ECH/métabolisme , Simulation de docking moléculaire , Structure moléculaire , Facteur-2 apparenté à NF-E2/métabolisme , SARS-CoV-2/physiologie , Cellules Vero , Réplication virale , Traitements médicamenteux de la COVID-19RÉSUMÉ
The cysteine protease cathepsin K is a target for the treatment of diseases associated with high bone turnover. Cathepsin K is mainly expressed in osteoclasts and responsible for the destruction of the proteinaceous components of the bone matrix. We designed various fluorescent activity-based probes (ABPs) and their precursors that bind to and inactivate cathepsin K. ABP 25 exhibited extraordinary potency (kinac/Ki = 35,300 M-1s-1) and selectivity for human cathepsin K. Crystal structures of cathepsin K in complex with ABP 25 and its nonfluorescent precursor 21 were determined to characterize the binding mode of this new type of acrylamide-based Michael acceptor with the particular orientation of the dibenzylamine moiety to the primed subsite region. The cyanine-5 containing probe 25 allowed for sensitive detection of cathepsin K, selective visualization in complex proteomes, and live cell imaging of a human osteosarcoma cell line, underlining its applicability in a pathophysiological environment.
Sujet(s)
Acrylamides/composition chimique , Cathepsine K/antagonistes et inhibiteurs , Inhibiteurs de la cystéine protéinase/composition chimique , Colorants fluorescents/composition chimique , Acrylamides/synthèse chimique , Acrylamides/métabolisme , Domaine catalytique , Cathepsine K/composition chimique , Cathepsine K/métabolisme , Lignée cellulaire tumorale , Inhibiteurs de la cystéine protéinase/synthèse chimique , Inhibiteurs de la cystéine protéinase/métabolisme , Conception de médicament , Colorants fluorescents/synthèse chimique , Colorants fluorescents/métabolisme , Humains , Microscopie confocale , Microscopie de fluorescence , Liaison aux protéinesRÉSUMÉ
The main protease of SARS-CoV-2 (Mpro ), the causative agent of COVID-19, constitutes a significant drug target. A new fluorogenic substrate was kinetically compared to an internally quenched fluorescent peptide and shown to be ideally suitable for high throughput screening with recombinantly expressed Mpro . Two classes of protease inhibitors, azanitriles and pyridyl esters, were identified, optimized and subjected to in-depth biochemical characterization. Tailored peptides equipped with the unique azanitrile warhead exhibited concomitant inhibition of Mpro and cathepsinâ L, a protease relevant for viral cell entry. Pyridyl indole esters were analyzed by a positional scanning. Our focused approach towards Mpro inhibitors proved to be superior to virtual screening. With two irreversible inhibitors, azanitrile 8 (kinac /Ki =37 500â m-1 s-1 , Ki =24.0â nm) and pyridyl ester 17 (kinac /Ki =29 100â m-1 s-1 , Ki =10.0â nm), promising drug candidates for further development have been discovered.
Sujet(s)
Antiviraux/pharmacologie , Traitements médicamenteux de la COVID-19 , Protéases 3C des coronavirus/antagonistes et inhibiteurs , Nitriles/pharmacologie , Inhibiteurs de protéases/pharmacologie , SARS-CoV-2/effets des médicaments et des substances chimiques , Antiviraux/composition chimique , COVID-19/métabolisme , COVID-19/virologie , Protéases 3C des coronavirus/métabolisme , Conception de médicament , Découverte de médicament , Cellules HEK293 , Tests de criblage à haut débit , Humains , Simulation de docking moléculaire , Nitriles/composition chimique , Inhibiteurs de protéases/composition chimique , Pyridines/composition chimique , Pyridines/pharmacologie , SARS-CoV-2/enzymologie , SARS-CoV-2/physiologie , Pénétration virale/effets des médicaments et des substances chimiquesRÉSUMÉ
A library of cathepsin S inhibitors of the dipeptide nitrile chemotype, bearing a bioisosteric sulfonamide moiety, was synthesized. Kinetic investigations were performed at four human cysteine proteases, i.e. cathepsins S, B, K and L. Compound 12 with a terminal 3-biphenyl sulfonamide substituent was the most potent (Kiâ¯=â¯4.02â¯nM; selectivity ratio cathepsin S/Kâ¯=â¯5.8; S/Lâ¯=â¯67) and 24 with a 4'-fluoro-4-biphenyl sulfonamide substituent the most selective cathepsin S inhibitor (Kiâ¯=â¯35.5â¯nM; selectivity ratio cathepsin S/Kâ¯=â¯57; S/Lâ¯=â¯31). In silico design and biochemical evaluation emphasized the impact of the sulfonamide linkage on selectivity and a possible switch of P2 and P3 substituents with respect to the occupation of the corresponding binding sites of cathepsin S.
Sujet(s)
Cathepsines/antagonistes et inhibiteurs , Dipeptides/synthèse chimique , Antienzymes/synthèse chimique , Nitriles/synthèse chimique , Sulfonamides/composition chimique , Séquence d'acides aminés , Sites de fixation , Cathepsine K/métabolisme , Cathepsine L/métabolisme , Simulation numérique , Cysteine proteases/métabolisme , Humains , Cinétique , Liaison aux protéines , Relation structure-activitéRÉSUMÉ
The archazolids are potent antiproliferative compounds that have recently emerged as a novel class of promising anticancer agents. Their complex macrolide structures and scarce natural supply make the development of more readily available analogues highly important. Herein, we report the design, synthesis and biological evaluation of four simplified and partially saturated archazolid derivatives. We also reveal important structure-activity relationship data as well as insights into the pharmacophore of these complex polyketides.
Sujet(s)
Antinéoplasiques/pharmacologie , Conception de médicament , Macrolides/pharmacologie , Thiazoles/pharmacologie , Antinéoplasiques/synthèse chimique , Antinéoplasiques/composition chimique , Lignée cellulaire tumorale , Survie cellulaire/effets des médicaments et des substances chimiques , Relation dose-effet des médicaments , Tests de criblage d'agents antitumoraux , Humains , Macrolides/synthèse chimique , Macrolides/composition chimique , Structure moléculaire , Relation structure-activité , Thiazoles/synthèse chimique , Thiazoles/composition chimiqueRÉSUMÉ
The cysteine protease cruzipain is considered to be a validated target for therapeutic intervention in the treatment of Chagas disease. A series of 26 new compounds were designed, synthesized, and tested against the recombinant cruzain (Cz) to map its S1/S1´ subsites. The same series was evaluated on a panel of four human cysteine proteases (CatB, CatK, CatL, CatS) and Leishmania mexicana CPB, which is a potential target for the treatment of cutaneous leishmaniasis. The synthesized compounds are dipeptidyl nitriles designed based on the most promising combinations of different moieties in P1 (ten), P2 (six), and P3 (four different building blocks). Eight compounds exhibited a Ki smaller than 20.0 nM for Cz, whereas three compounds met these criteria for LmCPB. Three inhibitors had an EC50 value of ca. 4.0 µM, thus being equipotent to benznidazole according to the antitrypanosomal effects. Our mapping approach and the respective structure-activity relationships provide insights into the specific ligand-target interactions for therapeutically relevant cysteine proteases.
Sujet(s)
Inhibiteurs de la cystéine protéinase/pharmacologie , Dipeptides/pharmacologie , Leishmania mexicana/enzymologie , Nitriles/pharmacologie , Protéines de protozoaire/antagonistes et inhibiteurs , Trypanocides/pharmacologie , Trypanosoma cruzi/enzymologie , Cysteine endopeptidases , Cysteine proteases/métabolisme , HumainsRÉSUMÉ
The complex nature of multifactorial diseases, such as Morbus Alzheimer, has produced a strong need to design multitarget-directed ligands to address the involved complementary pathways. We performed a purposive structural modification of a tetratarget small-molecule, that is contilisant, and generated a combinatorial library of 28 substituted chromen-4-ones. The compounds comprise a basic moiety which is linker-connected to the 6-position of the heterocyclic chromenone core. The syntheses were accomplished by Mitsunobu- or Williamson-type ether formations. The resulting library members were evaluated at a panel of seven human enzymes, all of which being involved in the pathophysiology of neurodegeneration. A concomitant inhibition of human acetylcholinesterase and human monoamine oxidase B, with IC50 values of 5.58 and 7.20 µM, respectively, was achieved with the dual-target 6-(4-(piperidin-1-yl)butoxy)-4H-chromen-4-one (7).
RÉSUMÉ
A series of inhibitors targeting human cathepsins have been designed and synthesized following a combinatorial approach. The compounds bear an α,ß-unsaturated phenyl vinyl sulfone or ethyl acrylate warhead and a peptidomimetic portion aligned to the non-primed binding region. Biochemical evaluation toward four human cathepsins was carried out and the kinetic characterization confirmed an irreversible mode of inhibition. Compound 6c combining the most advantageous building blocks for cathepsin S inhibition was identified as a potent cathepsin S inactivator exhibiting a second-order rate constant of 30600â¯M-1â¯s-1.