Journal of Enzyme Inhibition and Medicinal Chemistry最新文献

The enigmatic histone deacetylase 6 (HDAC6) is one of a kind among its family. Recent reports revealed that HDAC6 CD1 exhibits E3 ligase activity. Inspired by these researches, we attempted to develop drugs targeting HDAC6 via novel mechanism. Herein, we report a palladium catalysed transformation and purification method for hydroxamic acid dimers, and series of HDAC6 inhibitor-based dimer showing outstanding biological activities and capability of inducing auto-degradation. Our proof-of-concept was highlighted with 2-amino benzamide-based HDAC6 inhibitor dimers that exhibit great HDAC6 inhibition activity (3.9-15.4 nM), good HDAC1/6 selectivity (95-577), and excellent cytotoxicity against human hormone-resistant prostate cancer (HRPC) PC-3 and non-small cell lung cancer (NSCLC) A549 cell lines (5.9-11.3 and 6.6-17.9 μM, respectively) while simultaneously inducing HDAC6 degradation. These dimers not only induce apoptosis and autophagy but also interfere with kinetochore attachment by the detection of BUBR1 phosphorylation at S670.

The impact of the isoxazole derivative of usnic acid, ISOXUS (formerly known as 2b) on cancer and non-cancerous cell metabolism was investigated. ISOXUS significantly reduced the utilisation of most metabolic substrates that produce NADH or FADH2, mitochondrial electron flow and oxygen consumption rate (OCR) in MCF-7 breast cancer cells in contrast to HB2 normal epithelial cells. Molecular docking revealed that ISOXUS inhibits mitochondrial respiratory chain complex II, which was confirmed experimentally. Disturbance of electron flow in MCF-7 cells resulted in increased reactive oxygen species (ROS) production. They appeared crucial for ISOXUS-induced cancer cell vacuolization and a drop in survival as an antioxidant, α-tocopherol, protected against these processes. These findings indicate that ISOXUS is a metabolic inhibitor that targets mitochondrial complex II in breast cancer cells resulting in diminished ATP production and increased ROS formation which translates into reduced cell viability.

Sirtuins (SIRTs) are NAD+-dependent histone deacetylases, which play a key role in cancer progression; however, their prognostic values in breast cancer (BC) remain a subject of debate and controversy. Accumulative evidence suggests that each sirtuin possesses individual character, implicating its role in the regulation of multifaceted biological functions leading to BC initiation, progression and metastasis. Selisistat (EX527) is a potent, cell permeable, highly selective SIRT1 inhibitor. In the study, the tumour-suppressive effects of the SIRT1 inhibitor EX527 (selisistat) alone and in combination with paclitaxel (PAX) in different breast cancer cell lines and zebrafish xenograft models were investigated. The type of pharmacological drug-drug interaction between EX527 and PAX was determined using the isobolographic method. EX527 and PAX used individually inhibited proliferation, induced apoptosis and caused cell cycle arrest in G1 and subG1/G2 phases. Interestingly, the combination of these compounds used in the 1:1 dose-ratio augmented all these effects (IC_50add 29.52 ± 3.29 - 38.45 ± 5.26). The co-treatment of EX527 with PAX generated desirable additive drug-drug interaction. The simultaneous application of EX527 and PAX induced a stronger inhibition of tumour growth compared to individual treatments in zebrafish xenografts. In silico analysis revealed a protein-protein interaction pathway (SIRT1-AKT-S1PR1-GNAI1/GNAO1-Tubulin) connecting molecular targets of both ligands. To summarise, the combination of EX527 and PAX more effectively impairs breast cancer cell growth compared to individual treatments. However, further investigations are required to clarify the specific targets and molecular mechanisms underlying the activity of EX527:PAX in other preclinical models.

Papain-like protease (PLpro) is an attractive anti-coronavirus target. The development of PLpro inhibitors, however, is hampered by the limitations of the existing PLpro assay and the scarcity of validated active compounds. We developed a novel in-cell PLpro assay based on BRET and used it to evaluate and discover SARS-CoV-2 PLpro inhibitors. The developed assay demonstrated remarkable sensitivity for detecting the reduction of intracellular PLpro activity while presenting high reliability and performance for inhibitor evaluation and high-throughput screening. Using this assay, three protease inhibitors were identified as novel PLpro inhibitors that are structurally disparate from those previously known. Subsequent enzymatic assays and ligand-protein interaction analysis based on molecular docking revealed that ceritinib directly inhibited PLpro, showing high geometric complementarity with the substrate-binding pocket in PLpro, whereas CA-074 methyl ester underwent intracellular hydrolysis, exposing a free carboxyhydroxyl group essential for hydrogen bonding with G266 in the BL2 groove, resulting in PLpro inhibition.

Inhibiting apoptosis signal regulated kinase 1 (ASK1) is an attractive strategy for treating diseases such as non-alcoholic steatohepatitis and multiple sclerosis. Here, we report the discovery of a dibromo substituted quinoxaline fragment containing 26e as an effective small-molecule inhibitor of ASK1, with an IC₅₀ value of 30.17 nM. In addition, the cell survival rate of 26e at different concentrations was greater than 80%, especially at 0.4 μM. Its cell survival rate was significantly higher than GS-4997, indicating its good safety in normal human liver LO2 cells. The Oil Red O staining experiment showed that 26e decreased the lipid droplets in a dose-dependent manner. Further biochemical analyses revealed that 26e could reduce the content of T-CHO, LDL, and TG in FFA-induced LO2 cells, and had the potential to treat non-alcoholic fatty disease. These findings provide a good choice for the future development of ASK1 inhibitors.

The current therapies against gastric pathogen Helicobacter pylori are ineffective in over 20% of patients. Enzymes belonging to the purine salvage pathway are considered as novel drug targets in this pathogen. Therefore, the main aim of the current study was to determine the antibacterial activity of pyridoxal 5'-phosphate (PLP), an active form of vitamin B6, against reference and clinical strains of H. pylori. Using a broad set of microbiological, physicochemical (UV absorption, LC-MS, X-ray analysis) and in silico experiments, we were able to prove that PLP inhibits adenylosuccinate synthetase (AdSS) from H. pylori by the competition with GTP (IC₅₀^eq ∼30 nM). This behaviour was attributed to formation of a Schiff base with a lysine residue (a covalent bond with Lys322 in the GTP binding site of AdSS) and was potentiated by the presence of vitamin C. This antibacterial activity of PLP gives hope for its future use against H. pylori.

Butyrylcholinesterase (BuChE) and neuroinflammation have recently emerged as promising therapeutic directions for Alzheimer's disease (AD). Herein, we synthesised 19 novel pyranone-carbamate derivatives and evaluated their activities against cholinesterases and neuroinflammation. The optimal compound 7p exhibited balanced BuChE inhibitory activity (eqBuChE IC₅₀ = 4.68 nM; huBuChE IC₅₀ = 9.12 nM) and anti-neuroinflammatory activity (NO inhibition = 28.82% at 10 μM, comparable to hydrocortisone). Enzyme kinetic and docking studies confirmed compound 7p was a mix-type BuChE inhibitor. Additionally, compound 7p displayed favourable drug-likeness properties in silico prediction, and exhibited high BBB permeability in the PAMPA-BBB assay. Compound 7p had good safety in vivo as verified by an acute toxicity assay (LD₅₀ > 1000 mg/kg). Most importantly, compound 7p effectively mitigated cognitive and memory impairments in the scopolamine-induced mouse model, showing comparable effects to Rivastigmine. Therefore, we envisioned that compound 7p could serve as a promising lead compound for treating AD.

A series of triazolopyridine-based dual JAK/HDAC inhibitors were rationally designed and synthesised by merging different pharmacophores into one molecule. All triazolopyridine derivatives exhibited potent inhibitory activities against both targets and the best compound 4-(((5-(benzo[d][1, 3]dioxol-5-yl)-[1, 2, 4]triazolo[1, 5-a]pyridin-2-yl)amino)methyl)-N-hydroxybenzamide (19) was dug out. 19 was proved to be a pan-HDAC and JAK1/2 dual inhibitor and displayed high cytotoxicity against two cancer cell lines MDA-MB-231 and RPMI-8226 with IC₅₀ values in submicromolar range. Docking simulation revealed that 19 fitted well into the active sites of HDAC and JAK proteins. Moreover, 19 exhibited better metabolic stability in vitro than SAHA. Our study demonstrated that compound 19 was a promising candidate for further preclinical studies.

In this article, a new series of 2-((3,5-disubstituted-2-thioxo-imidazol-1-yl)imino)acenaphthylen-1(2H)-ones were synthesized. Imidazole-2-thione with acenaphthylen-one gave a hybrid scaffold that integrated key structural elements essential for DNA damage via direct DNA intercalation and inhibition of the topoisomerase II enzyme. All the synthesized compounds were screened to detect their DNA damage using a terbium fluorescent probe. Results demonstrated that 4-phenyl-imidazoles 5b and 5e in addition to 4-(4-chlorophenyl)imidazoles 5h and 5j would induce detectable potent damage in ctDNA. The four most potent compounds as DNA intercalators were further evaluated for their antiproliferative activity against HepG2, MCF-7 and HCT-116 utilizing the MTT assay. The highest anticancer activity was recorded with compounds 5b and 5h against the breast cancer cell line MCF-7 which were 1.5- and 3- folds more active than doxorubicin, respectively. Therefore, imidazole-2-thione tethered acenaphthylenone derivatives can be considered as promising scaffold for the development of effective dual DNA intercalators and topoisomerase II inhibitors.