Discovery of (2,4)-4-(()-2-Amino-3-methylbutanamido)-2-(4-boronobutyl)pyrrolidine-2-carboxylic Acid (AZD0011), an Actively Transported Prodrug of a Potent Arginase Inhibitor to Treat Cancer.

Arginase is a promising immuno-oncology target that can restore the innate immune response. However, it's highly polar active site often requires potent inhibitors to mimic amino acids, leading to poor passive permeability and low oral exposure. Using structure-based drug design, we discovered a novel proline-based arginase inhibitor () that was potent but had low oral bioavailability in rat.

Design and Synthesis of Acyclic Boronic Acid Arginase Inhibitors.

Arginase has long been a target of interest in immuno-oncology, but discovering an orally bioavailable inhibitor is severely constrained by the requisite boronic acid pharmacophore. We began our drug discovery campaign by building off the β-position of the literature inhibitor ABH (). A divergent synthesis with an Ireland-Claisen rearrangement as the key step allowed access to numerous compounds, some of which we crystallized in the active site of arginase 2.

Development of a Series of Pyrrolopyridone MAT2A Inhibitors.

The optimization of an allosteric fragment, discovered by differential scanning fluorimetry, to an in vivo MAT2a tool inhibitor is discussed. The structure-based drug discovery approach, aided by relative binding free energy calculations, resulted in AZ'9567 (), a potent inhibitor in vitro with excellent preclinical pharmacokinetic properties. This tool showed a selective antiproliferative effect on methylthioadenosine phosphorylase (MTAP) KO cells, both in vitro and in vivo, providing further evidence to support the utility of MAT2a inhibitors as potential anticancer therapies for MTAP-deficient tumors.

Development of hydrolytic stability screening methods for early drug discovery with high differentiation and predictive power.

In early drug discovery, hydrolytic chemical stability is routinely assessed to ensure future developability of quality compounds and stability in in vitro test environments. When conducting high-throughput hydrolytic stability analyses as part of the compound risk assessment, aggressive conditions are typically applied to allow for faster screening. However, it can be challenging to extrapolate the real stability risk and to rank compounds due to over-estimating risk based on aggressive conditions and the narrow discriminative window.

Photocatalyzed Decarboxylative Addition of N-Substituted Acetic Acids to Aldehydes.

Herein, we report a photoredox-catalyzed decarboxylative addition of N-substituted acetic acids to aldehydes to generate secondary alcohols under mild reaction conditions. Protic solvents were found to be critical to the successful implementation of this methodology. This strategy enables the formation of a novel C-C bond between aldehydes and N-substituted acetic acid derivatives of weakly nucleophilic and medicinally relevant heteroaryls such as indoles, pyrroles, indazoles, and azaindoles.

Script-based automation of analytical instrument software tasks.

In laboratories with multiple identical analytical instruments and consistent sample workflows, analysts frequently perform repetitive software control steps, yet automation options in vendor-supplied instrument software are generally limited and may not support the desired laboratory workflow. Scripts that automate tasks to monitor systems, streamline worklist creation, or minimize downtime can save valuable personnel time and reduce errors. AutoHotkey is a free, open-source scripting language for Windows that allows users with no programming experience to easily create scripts automating a wide variety of activities.

Optimization of an Imidazo[1,2-]pyridine Series to Afford Highly Selective Type I1/2 Dual Mer/Axl Kinase Inhibitors with Efficacy.

Inhibition of Mer and Axl kinases has been implicated as a potential way to improve the efficacy of current immuno-oncology therapeutics by restoring the innate immune response in the tumor microenvironment. Highly selective dual Mer/Axl kinase inhibitors are required to validate this hypothesis. Starting from hits from a DNA-encoded library screen, we optimized an imidazo[1,2-]pyridine series using structure-based compound design to improve potency and reduce lipophilicity, resulting in a highly selective probe compound .

Prolonged tau clearance and stress vulnerability rescue by pharmacological activation of autophagy in tauopathy neurons.

Tauopathies are neurodegenerative diseases associated with accumulation of abnormal tau protein in the brain. Patient iPSC-derived neuronal cell models replicate disease-relevant phenotypes ex vivo that can be pharmacologically targeted for drug discovery. Here, we explored autophagy as a mechanism to reduce tau burden in human neurons and, from a small-molecule screen, identify the mTOR inhibitors OSI-027, AZD2014 and AZD8055.

Discovery and optimization of covalent Bcl-xL antagonists.

Over the last ten years, targeted covalent inhibition has become a key discipline within medicinal chemistry research, most notably in the development of oncology therapeutics. One area where this approach is underrepresented, however, is in targeting protein-protein interactions. This is primarily because these hydrophobic interfaces lack appropriately located cysteine residues to allow for standard conjugate addition chemistry.

Inhibition of Mcl-1 through covalent modification of a noncatalytic lysine side chain.

Targeted covalent inhibition of disease-associated proteins has become a powerful methodology in the field of drug discovery, leading to the approval of new therapeutics. Nevertheless, current approaches are often limited owing to their reliance on a cysteine residue to generate the covalent linkage. Here we used aryl boronic acid carbonyl warheads to covalently target a noncatalytic lysine side chain, and generated to our knowledge the first reversible covalent inhibitors for Mcl-1, a protein-protein interaction (PPI) target that has proven difficult to inhibit via traditional medicinal chemistry strategies.

Highly Chemoselective Iridium Photoredox and Nickel Catalysis for the Cross-Coupling of Primary Aryl Amines with Aryl Halides.

A visible-light-promoted iridium photoredox and nickel dual-catalyzed cross-coupling procedure for the formation C-N bonds has been developed. With this method, various aryl amines were chemoselectively cross-coupled with electronically and sterically diverse aryl iodides and bromides to forge the corresponding C-N bonds, which are of high interest to the pharmaceutical industries. Aryl iodides were found to be a more efficient electrophilic coupling partner.

Discovery and Characterization of New Hydroxamate Siderophores, Baumannoferrin A and B, produced by Acinetobacter baumannii.

Acinetobacter baumannii AYE does not produce acinetobactin but grows under iron limitation. Accordingly, analyses of AYE iron-restricted culture supernatants resulted in the isolation of two fractions, which contained only hydroxamates and showed siderophore activity. Structural analyses identified baumannoferrin A and baumannoferrin B, which differ only by a double bond.

Thinking outside the "bug": a unique assay to measure intracellular drug penetration in gram-negative bacteria.

Significant challenges are present in antibiotic drug discovery and development. One of these is the number of efficient approaches Gram-negative bacteria have developed to avoid intracellular accumulation of drugs and other cell-toxic species. In order to better understand these processes and correlate in vitro enzyme inhibition to whole cell activity, a better assay to evaluate a key factor, intracellular accumulation of the drug, is urgently needed.

Alkylidene Oxapenem β-Lactamase Inhibitors Revisited: Potent Broad Spectrum Activity but New Stability Challenges.

We present a comprehensive study of C6-alkylidene containing oxapenems. We show that this class of β-lactamase inhibitors possesses an unprecedented spectrum with activity against class A, C, and D enzymes. Surprisingly, this class of compounds displayed significant photolytic instability in addition to the known hydrolytic instability.

Discovery of ATP-Competitive Inhibitors of tRNAIle Lysidine Synthetase (TilS) by High-Throughput Screening.

A novel, ultrahigh-throughput, fluorescence anisotropy-based assay was developed and used to screen a 1.4-million-sample library for compounds that compete with adenosine triphosphate (ATP) for binding to Escherichia coli tRNA(Ile) lysidine synthetase (TilS), an essential, conserved, ATP-dependent, tRNA-modifying enzyme of bacterial pathogens. TilS modifies a cytidine base in the anticodon loop of Ile2 tRNA by attaching lysine, thereby altering codon recognition of the CAU anticodon from AUG (methionine) to AUA (isoleucine).