ChemMedChem最新文献

The development of the KRAS G12C inhibitor sotorasib was a major advance towards drugging KRAS.  However, the G12C mutation is only found in about 10% of tumors with a KRAS mutation.  KRAS tyrosine amino acids could provide alternative sites for covalent drug development. Here, we screen a library of aryl sulfonyl fluorides to explore whether tyrosines on KRAS are accessible for covalent bond formation. We identify compound 1 (SOF-436), which inhibits KRAS nucleotide exchange by guanine exchange factor SOS1 and the binding of KRAS to effector protein RAF.  Tyr-64 was the major reaction site of 1 (SOF-436), although minor reaction at Tyr-71 was also observed. The fragment engages the Switch II pocket of KRAS based on mass spectrometry, nucleotide exchange, effector protein binding, nuclear magnetic resonance (NMR), and molecular dynamics simulations. Co-crystal structures of smaller fragments covalently bound to KRAS at Tyr-71 provide a strategy for the development of Switch I/II KRAS covalent inhibitors. A NanoBRET assay revealed that the compound and its analogs inhibit KRAS binding to RAF in mammalian cells. Although not yet suitable as chemical probes, these fragments provide starting points for small molecules to investigate tyrosine as a nucleophile for covalent inhibition of KRAS in tumors.

The rise of drug resistances in malaria necessitates the exploration of novel therapeutic strategies. Targeting epigenetic pathways could open new, promising treatment avenues. In this study, the focus is on the essential Bromodomain protein 1 (PfBDP1) of the malaria pathogen Plasmodium falciparum. Utilizing the pan-selective bromodomain inhibitor MPM6, a potent initial hit is identified and it is subsequently developed into a nanomolar binder. Through a combination of virtual docking, isothermal titration calorimetry, and X-ray crystallography, the molecular interactions of the new inhibitors with the bromodomain (BRD) of the protein (PfBDP1-BRD) are elucidated. The findings include the first co-crystallized inhibitors with the structures of PfBRD1-BRD as well as the bromodomain of the close homologous protein of Plasmodium vivax (PvBDP1-BRD). The structures provide new insights into their binding mechanisms. Further validation using conditional knockdown of PfBDP1 in P. falciparum demonstrates parasite sensitivity to the inhibitor, underscoring its potential in a targeted therapeutic approach against malaria.

This study explores the anti-cancer potential of N-methylated open-ring derivatives of carborane-substituted diclofenac analogs. By N-methylation, the open-chain form could be trapped and cyclization back to lactam or amidine derivatives was inhibited. A small library of carborane- and phenyl-based secondary and tertiary arylamines bearing carboxylic acid or nitrile groups was synthesized and analyzed for their COX-affinity in vitro and in silico. The compounds were further evaluated against mouse adenocarcinoma (MC38), human colorectal carcinoma (HCT116) and human colorectal adenocarcinoma (HT29) cell lines and showed potent cytotoxicity. Additional biological assessments of the mode of action were performed using flow cytometric techniques and fluorescence microscopy. The data obtained revealed a common antiproliferative effect coupled with the induction of caspase-independent apoptosis and the specific effects of the compound on the phenotype of MC38 cells, resulting in impaired cell viability of MC38 cells and satisfactory selectivity exceeding the antitumor activity of diclofenac.

Gram-negative bacteria release lipopolysaccharides (LPS) into our bodies, acting as potent modulators of inflammation. These molecules can enhance or attenuate inflammation. Beyond the largely studied MD2/TLR4, a complex set of other receptors interact with LPS producing diverse effects. Understanding how the structural features of LPS affect the activity and crosstalk among various receptors is crucial for developing new drugs to treat immune-related pathologies. This review aims to persuade researchers with interest in this field to perform their research activities by always using a structure to function approach. More details can be found in article cmdc.202400780 by Marcello Mercogliano, Flaviana Di Lorenzo, and co-workers.

This cover art highlights a key improvement in CXCR4-targeting radioligands derived from the endogenous peptide inhibitor EPI-X4: the removal of a lysine residue in their octapeptide sequence. By reducing the radioligand's overall charge, this modification effectively lowers the undesirably high kidney accumulation seen in the first generation of these radioligands and improves CXCR4 affinity. This work brings EPI-X4 derived radiotheranostics closer to actuation. More details can be found in 10.1002/cmdc.202400773 by Melpomeni Fani and co-workers.

SiRNA are promising therapeutic molecules that require delivery systems to reach their targets. Several siRNA delivery systems, such as lipid- or peptide-based nanoparticles, have been developed. In this context, we previously conceived a cell-penetrating peptide WRAP5 forming nanoparticles in the presence of siRNAs and validated the efficiency of this delivery system in inhibiting protein expression. In the pathophysiological context of acute myocardial infarction, which causes a pH drop in the ischemic heart tissue, we optimized the WRAP5-based nanoparticles for a pH-sensitive siRNA-targeted delivery. Therefore, pH-sensitive acyl hydrazone linkers were used to graft polyethylene (PEG) on the WRAP5 peptide. Proof of concept of the targeted delivery was performed using siRNA silencing the Fas-associated death domain (FADD) containing protein implicated in apoptosis during myocardial ischemia-reperfusion injury on two human cell models (vascular endothelial cells and hiPSC-derived cardiomyocytes). Our results show that only WRAP5 nanoparticles PEGylated via an appropriate acyl hydrazone linker with tuned pH sensitivity can induce a specific FADD knockdown at pH 5 compared to naked nanoparticles. These optimized WRAP-based nanoparticles could be a novel therapeutic tool for treating myocardial infarction by inhibiting apoptosis induced by reperfusion and maximizing local delivery of the nanoparticle content at the site of injured cells.

Recently, the term "corrination" was coined to describe the conjugate modification of a peptide, protein, small molecule, or radionuclide with a corrin ring-containing molecule. By exploiting the innate chemicophysical properties of corrin ring-containing compounds, corrination has been explored for drug development and targeted/localized delivery of probes and therapeutics. Most recently, it is in the field of peptide-based therapeutics that corrination is generating significant interest. Peptide-based drugs possess several limitations that restrict their clinical application, including poor solubility and stability, low oral bioavailability, and negative side effects often due to drug distribution. In this mini review, the design and synthetic approaches to peptide corrination are described, along with examples of in vitro, ex vivo, and in vivo biological evaluations of corrinated conjugates, which demonstrate the broad applicability of the technique, namely 1) mitigated peptide aggregation, 2) improved protection against proteolysis, 3) reduced negative side effects via targeted localization, 4) regioselective production of peptide disulfide bonds, and 5) improved oral drug absorption. Herein, it is described how corrination offers a facile route to improving peptide pharmacokinetic and pharmacodynamic properties, making this a useful platform technology in the field of peptide drug development.

A novel pheophorbide derivative, trimethyl-152-[L-aspartyl]pheophorbide a was synthesised and investigated for anti-tumor activity. The prepared photosensitizer had good absorption in the phototherapeutic window and high ROS yields. It exhibited excellent phototoxicity higher than reference compound m-THPC when irradiated by 650 nm light in vitro, and obvious photodynamic anti-tumor effect in vivo. It causes cellular apoptosis or necrosis under laser irradiation and localizes in mitochondria, lysosome, and endoplasmic reticulum. The observed high efficacy was rationalized by efficient introduction into the blood by facile transfer through membranes, which is supported by molecular dynamics simulation studies. This work provides a new candidate photosensitizer for anti-cancer treatment.

Boron Neutron Capture Therapy (BNCT) leverages the nuclear reaction between boron-10 and thermal neutrons to selectively destroy cancer cells while minimizing damage to surrounding healthy tissues. This therapy has found use in treating glioblastoma, which as a brain cancer, is difficult to treat using conventional radiotherapy, surgery, and chemotherapy due to location and the risk of brain damage. However, to work, the cells must contain 10B. 4-Borono-l-phenylalanine (l-BPA) is the most frequently used boron delivery agent in this therapy. Surprisingly, despite its seemingly simple structure, there is no consensus approach to making it-the synthesis of l-BPA has been approached through multiple routes, reflecting the challenges in producing high-purity, isotopically enriched material. When a new site is looking to make this essential material, it can be challenging to determine the best route for the situation as there is no critical analysis comparing and discussing the relative merits of the approaches. Herein, we comprehensively and critically examine and compare the reported methods, from both the academic and patent literature, used to synthesize l-BPA. The review also highlights the limitations of each method regarding scalability, cost-effectiveness, and safety, especially considering the high cost of isotopically enriched 10B.

Galectin-3 (Gal-3), a β-galactoside-binding lectin, is implicated in diverse cellular functions ranging from immune response modulation to tissue homeostasis. Notably, increased Gal-3 expression has been linked to the progression of numerous diseases, including cancer, fibrosis, and cardiovascular disorders, underscoring its potential as a therapeutic target. Small molecule inhibitors have been discovered and are valuable tools to study such diseases. We report here the discovery of novel, galactose-based, small molecule inhibitors such as compound 12 which are orally bioavailable and show efficacy in a mouse model of acute liver injury and fibrosis (CCl₄ model). The use of structure-based drug design (docking of a virtual library of amides based on acid 2) was key in the process towards potent, nanomolar inhibitors.