7 research outputs found
Preparative Microfluidic Electrosynthesis of Drug Metabolites
In vivo, a drug molecule undergoes
its first chemical transformation
within the liver via CYP450-catalyzed oxidation. The chemical outcome
of the first pass hepatic oxidation is key information to any drug
development process. Electrochemistry can be used to simulate CYP450
oxidation, yet it is often confined to the analytical scale, hampering
product isolation and full characterization. In an effort to replicate
hepatic oxidations, while retaining high throughput at the preparative
scale, microfluidic technology and electrochemistry are combined in
this study by using a microfluidic electrochemical cell. Several commercial
drugs were subjected to continuous-flow electrolysis. They were chosen
for their various chemical reactivity: their metabolites in vivo are
generated via aromatic hydroxylation, alkyl oxidation, glutathione
conjugation, or sulfoxidation. It is demonstrated that such metabolites
can be synthesized by flow electrolysis at the 10 to 100 mg scale,
and the purified products are fully characterized
Synthesis of Oxindolyl Pyrazolines and 3‑Amino Oxindole Building Blocks <i>via</i> a Nitrile Imine [3 + 2] Cycloaddition Strategy
The [3 + 2] dipolar cycloaddition reaction of nitrile imines with 3-alkylidene oxindoles is described. The pyrazoline spiroadducts were obtained in high yields and with excellent regio- and diastereoselectivities. These spirocyclic intermediates have been elaborated to synthetically versatile 3-amino oxindole building blocks such as β-amino nitrile, 1,3-diamine, and pyrrolo[2,3-<i>b</i>]indoline derivatives
Structure-Guided Strategy for the Development of Potent Bivalent ERK Inhibitors
ERK
is the effector kinase of the RAS-RAF-MEK-ERK signaling cascade,
which promotes cell transformation and malignancy in many cancers
and is thus a major drug target in oncology. Kinase inhibitors targeting
RAF or MEK are already used for the treatment of certain cancers,
such as melanoma. Although the initial response to these drugs can
be dramatic, development of drug resistance is a major challenge,
even with combination therapies targeting both RAF and MEK. Importantly,
most resistance mechanisms still rely on activation of the downstream
effector kinase ERK, making it a promising target for drug development
efforts. Here, we report the design and structural/functional characterization
of a set of bivalent ERK inhibitors that combine a small molecule
inhibitor that binds to the ATP-binding pocket with a peptide that
selectively binds to an ERK protein interaction surface, the D-site
recruitment site (DRS). Our studies show that the lead bivalent inhibitor,
SBP3, has markedly improved potency compared to the small molecule
inhibitor alone. Unexpectedly, we found that SBP3 also binds to several
ERK-related kinases that contain a DRS, highlighting the importance
of experimentally verifying the predicted specificity of bivalent
inhibitors. However, SBP3 does not target any other kinases belonging
to the same CMGC branch of the kinome. Additionally, our modular click
chemistry inhibitor design facilitates the generation of different
combinations of small molecule inhibitors with ERK-targeting peptides
Inhibition of Protein Kinase C-Driven Nuclear Factor-κB Activation: Synthesis, Structure−Activity Relationship, and Pharmacological Profiling of Pathway Specific Benzimidazole Probe Molecules
A unique series of biologically active chemical probes that selectively inhibit NF-κB activation induced by protein kinase C (PKC) pathway activators have been identified through a cell-based phenotypic reporter gene assay. These 2-aminobenzimidazoles represent initial chemical tools to be used in gaining further understanding on the cellular mechanisms driven by B and T cell antigen receptors. Starting from the founding member of this chemical series <b>1a</b> (notated in PubChem as CID-2858522), we report the chemical synthesis, SAR studies, and pharmacological profiling of this pathway-selective inhibitor of NF-κB activation
Identification of Inhibitors of NOD1-Induced Nuclear Factor-κB Activation
NOD1 (nucleotide-binding oligomerization domain 1) protein is a member of the NLR (NACHT and leucine rich repeat domain containing proteins) protein family, which plays a key role in innate immunity as a sensor of specific microbial components derived from bacterial peptidoglycans and induction of inflammatory responses. Mutations in NOD proteins have been associated with various inflammatory diseases that affect NF-κB (nuclear factor κB) activity, a major signaling pathway involved in apoptosis, inflammation, and immune response. A luciferase-based reporter gene assay was utilized in a high-throughput screening program conducted under the NIH-sponsored Molecular Libraries Probe Production Center Network program to identify the active scaffolds. Herein, we report the chemical synthesis, structure–activity relationship studies, downstream counterscreens, secondary assay data, and pharmacological profiling of the 2-aminobenzimidazole lead (compound <b>1c</b>, ML130) as a potent and selective inhibitor of NOD1-induced NF-κB activation
Discovery of a Plasmodium falciparum Glucose-6-phosphate Dehydrogenase 6‑phosphogluconolactonase Inhibitor (<i>R</i>,<i>Z</i>)‑<i>N</i>‑((1-Ethylpyrrolidin-2-yl)methyl)-2-(2-fluorobenzylidene)-3-oxo-3,4-dihydro‑2<i>H</i>‑benzo[<i>b</i>][1,4]thiazine-6-carboxamide (ML276) That Reduces Parasite Growth in Vitro
A high-throughput screen of the NIH’s MLSMR collection
of
∼340000 compounds was undertaken to identify compounds that
inhibit Plasmodium falciparum glucose-6-phosphate
dehydrogenase (<i>Pf</i>G6PD). <i>Pf</i>G6PD is
important for proliferating and propagating P. falciparum and differs structurally and mechanistically from the human orthologue.
The reaction catalyzed by glucose-6-phosphate dehydrogenase (G6PD)
is the first, rate-limiting step in the pentose phosphate pathway
(PPP), a key metabolic pathway sustaining anabolic needs in reductive
equivalents and synthetic materials in fast-growing cells. In P. falciparum, the bifunctional enzyme glucose-6-phosphate
dehydrogenase-6-phosphogluconolactonase (<i>Pf</i>GluPho)
catalyzes the first two steps of the PPP. Because P.
falciparum and infected host red blood cells rely
on accelerated glucose flux, they depend on the G6PD activity of <i>Pf</i>GluPho. The lead compound identified from this effort,
(<i>R</i>,<i>Z</i>)-<i>N</i>-((1-ethylpyrrolidin-2-yl)Âmethyl)-2-(2-fluorobenzylidene)-3-oxo-3,4-dihydro-2<i>H</i>-benzoÂ[<i>b</i>]Â[1,4]Âthiazine-6-carboxamide, <b>11</b> (ML276), is a submicromolar inhibitor of <i>Pf</i>G6PD (IC<sub>50</sub> = 889 nM). It is completely selective for the
enzyme’s human isoform, displays micromolar potency (IC<sub>50</sub> = 2.6 μM) against P. falciparum in culture, and has good drug-like properties, including high solubility
and moderate microsomal stability. Studies testing the potential advantage
of inhibiting <i>Pf</i>G6PD in vivo are in progress
Discovery of ML314, a Brain Penetrant Nonpeptidic β‑Arrestin Biased Agonist of the Neurotensin NTR1 Receptor
The neurotensin 1 receptor (NTR1) is an important therapeutic target
for a range of disease states including addiction. A high-throughput
screening campaign, followed by medicinal chemistry optimization,
led to the discovery of a nonpeptidic β-arrestin biased agonist
for NTR1. The lead compound, 2-cyclopropyl-6,7-dimethoxy-4-(4-(2-methoxyphenyl)-piperazin-1-yl)Âquinazoline, <b>32</b> (ML314), exhibits full agonist behavior against NTR1 (EC<sub>50</sub> = 2.0 μM) in the primary assay and selectivity against
NTR2. The effect of <b>32</b> is blocked by the NTR1 antagonist
SR142948A in a dose-dependent manner. Unlike peptide-based NTR1 agonists,
compound <b>32</b> has no significant response in a Ca<sup>2+</sup> mobilization assay and is thus a biased agonist that activates the
β-arrestin pathway rather than the traditional G<sub><i>q</i></sub> coupled pathway. This bias has distinct biochemical
and functional consequences that may lead to physiological advantages.
Compound <b>32</b> displays good brain penetration in rodents,
and studies examining its in vivo properties are underway