Sodium-hydrogen exchanger 1 (NHE1) is a potential target for drug discovery of heart failure (HF). Cardioprotection effect of empagliflozin (EMPA) was reported to be related to binding with NHE1 protein. Herein, a series of NHE1 inhibitors bearing benzhydryl and diphenyl ketone skeleton were rationally designed and efficiently synthesized. Cell viability assay and pH recovery experiment based on H9c2 cells were conducted and compound 7g was found to have equal NHE1 inhibitory activity to cariporide (0.64 μM) with the IC values of 0.78 μM. In vitro, 7g at 1 μM effectively rescued glucose deprivation (GD)-induced cellular damage by decreased overload of Ca concentration and reactive oxygen species (ROS), improved mitochondrial dysfunction and autophagy. In vivo, compared with the clinically approved drug empagliflozin (30 mg/kg), 7g alleviated left ventricular systolic dysfunction in a heart failure model induced by isoproterenol (ISO) at lower concentration (10 mg/kg). In summary, this study supplies a promising lead compound with novel scaffold for NHE1 inhibitor and also provide a feasible strategy for HF drug discovery.

Transformer-based chemical language models (CLMs) were derived to generate structurally and topologically diverse embeddings of core structure fragments, substituents, or core/substituent combinations in chemically proper compounds, representing a design task that is difficult to address using conventional structure generation methods. To this end, CLM variants were challenged to learn different fragment-to-compound mappings in the absence of structural rules or any other fragment linking or synthetic information. The resulting alternative models were found to have high syntactic fidelity, but displayed notable differences in their ability to generate valid candidate compounds containing test fragments, with a clear preference for a model variant processing core/substituent combinations. However, the majority of valid candidate compounds generated with all models were distinct from training data and structurally novel. In addition, the CLMs exhibited high chemical diversification capacity and often generated structures with new topologies not encountered during training. Furthermore, all models produced large numbers of close structural analogues of known bioactive compounds covering a large target space, thus indicating the relevance of newly generated candidates for pharmaceutical research. As a part of our study, the new methodology and all data are made publicly available.

Desensitizing transient receptor potential ankyrin 1 (TRPA1) cation channel through agonists emerges as an effective strategy for developing analgesics. Many TRPA1 agonists are electrophilic irritants, including BITC and iodoacetamide (IA), which covalently bind to cysteine residues in the cytoplasmic region of the channel. The electrophile JT010 is also recognized as a potent TRPA1 agonist via covalent modification of Cys621, whose irritant effects have been confirmed in humans, highlighting a commonly undesirable property of these electrophilic agonists. Cryo-electron microscopy (cryo-EM) structures have shown that these electrophiles induce a strong driving force for conformational change through electrophilic modification of TRPA1. However, the stable activated conformation induced by electrophiles might delay subsequent desensitization, leading to prolonged TRPA1-mediated nociception responses in vivo. Therefore, developing non-electrophilic TRPA1 agonists may mitigate the irritation associated with electrophilic agonists by accelerating the desensitizing process. To test this hypothesis, we designed and synthesized a series of novel TRPA1 agonists by removing the electrophilic functional group of JT010. Among these synthetic compounds, whole-cell patch clamp recording assays identified compound 21 as a selective TRPA1 agonist with an EC of 25.47 ± 1.56 μM for hTRPA1, exhibiting faster desensitization (τ = 20.02 ± 1.66 s) of mTRPA1 compared to electrophiles JT010 (41.71 ± 4.10 s) and BITC (68.05 ± 5.57 s). Importantly, compound 21 demonstrated effective analgesic properties without irritation in mice. Our findings support the hypothesis that facilitating rapid desensitization of TRPA1 by non-electrophilic channel agonists enhances anti-nociceptive effects. Compound 21 may serve as a promising lead for further optimization.

Small molecule-based entry inhibitors (EIs) may be promising to reduce human immunodeficiency virus (HIV) infection. Taking our recently described HIV entry inhibitor, ADS-J21, as prototype, a new series of triarylmethane analogues have been designed and synthesized. Among them, compound L14 emerged as the most promising showing significant antiviral activity against HIV-1 infection (IC: 0.39 μM) and low cytotoxicity (CC: 210.03 μM, SI: 537.1). L14 also exhibit cell-cell fusion inhibition activity and antiviral activity against both HIV-1 T20-resistant and primary strains, with potency in the submicromolar range. Mechanistically, L14 interacts by hydrogen bonding and π-π stacking with Lys35, Gln38 and Trp32 residues present in the gp41 NHR pocket. Additionally, L14 did not show significant toxicity in acute and subacute toxicity studies performed on healthy Kunming mice. The oral bioavailability of L14 in Sprague Dawley (SD) rats is about 7.0 %. Therefore, compound L14 holds promise as a novel HIV-1 small-molecule entry inhibitor although a further ten-fold improvement in activity is needed for further development.

Depressive symptoms are the most common neuropsychiatric disorders at all stages of Parkinson's disease (PD). Imbalances of the kynurenine pathway of tryptophan metabolism have been closely linked to the pathogenesis of PD and depression. Herein, we designed and synthesized a series of 1-thienyl-β-carboline derivatives as IDO1 and TDO dual inhibitors; among them, compound CZ-17 manifested moderate inhibitory activities to IDO1 and TDO with IC values of 0.33 and 1.78 μM, respectively. CZ-17 inhibited the kynurenine pathway of tryptophan degradation at the cellular level, and remarkably reduced the kynurenine/tryptophan ratio. CZ-17 displayed directly neuroprotective effect in corticosterone-induced PC12 neural cell injury model. In vivo experiments demonstrated that CZ-17 significantly increased dopamine and serotonin levels, improved MPTP-induced motor disability and rescued LPS-induced depressive behavior in zebrafish model. Acute toxicity tests of CZ-17 in zebrafish embryos showed no toxicity within the effective dose range. Additionally, CZ-17 displayed the potential to cross the BBB via passive diffusion according to ADMET prediction and Caco-2 permeability assay. Thus, CZ-17 may be a promising drug candidate for PD complicating depression.

In the recent decade, targeting ferroptosis for cancer therapy has attracted remarkable attention. Interestingly, the transcriptional regulator Nur77, a promising therapeutic target in cancer, has been recently identified as a crucial regulator of ferroptosis. However, no ferroptosis inducer targeting Nur77 has been reported currently. In this study, we built upon our prior research on Nur77 modulator 4-PQBH to design and synthesize four series of new compounds, with the objective of developing novel Nur77-mediated ferroptosis inducers. Among them, compound 8f exhibited the most potency against the tested cancer cell lines, including human estrogen positive breast cancer and triple-negative breast cancer cell lines, while displaying lower toxicity towards human normal cell lines HaCaT and MCF-10A (IC> 50 μM). Furthermore, 8f demonstrated superior Nur77-binding activity in comparison to the reference compound Csn-B, and it has the capacity to activate the Nur77-driven luciferase activity and increase the protein level of Nur77. Remarkably, 8f induced an increase in the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and lipid peroxidation, concurrently with a reduction in the expression of GPX4 protein, culminating in the induction of ferroptosis in a Nur77-dependent manner. In vivo, 8f treatment has been observed to significantly suppress MCF7 xenograft tumor growth. Consequently, a novel ferroptosis inducer targeting Nur77 (8f) is first reported as a potent anti-EPBC agent, providing may serve as a promising lead for further drug development targeting Nur77-mediated ferroptosis.

Diabetes mellitus is not only a critical health concern in this era but also a major cause of damage to other organs such as eyes, nerves, kidneys, hearts and liver. Inhibiting α-amylase enzyme is considered as one of the key strategies for controlling chronic hyperglycemia. Therefore, the current work focuses on design and discovery of a series of thioxothiazolidine derivatives (5a-u and 6a-g) as selective α-amylase inhibitors. The target compounds were synthesized using the Knoevenagel condensation approach and evaluated for their α-amylase and α-glucosidase inhibitory activities. The in vitro assay results demonstrated that the tested thioxothiazolidine derivatives possess significantly high potency than the standard drug acarbose against α-amylase but were inactive against α-glucosidase. Among them, compound 5r exhibited remarkable inhibitory potential depicting an IC value of 0.71 ± 0.01 μM, significantly outperforming acarbose against α-amylase. In vivo results further demonstrated that the treatment of diabetic rats with compound 5r led to a significant reduction in blood glucose level, indicating its effectiveness in managing hyperglycemia. Biochemical profiling of the treated rats revealed favorable outcomes, including improved urea, creatinine, ALT, AST, ALP, and HbA1C values. Furthermore, in vivo testing in diabetic rats also demonstrated that treatment with compound 5r caused significant histopathological improvements in the kidney, liver and pancreas compared to acarbose. The Lineweaver-Burk plot analysis indicated that compound 5r inhibits α-amylase through a mixed type of inhibition mechanism. Furthermore, molecular docking and dynamics simulations confirmed the in vitro findings while pharmacokinetic properties suggested compound 5r as a favorable drug candidate for the treatment of diabetic complications.

Nirmatrelvir is a substrate-related inhibitor of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) main protease (M) that is clinically used in combination with ritonavir to treat COVID-19. Derivatives of nirmatrelvir, modified at the substrate P2-equivalent position, have been developed to fine-tune inhibitor properties and are now in clinical use. We report the synthesis of nirmatrelvir derivatives with a (R)-4,4-dimethyl-4-silaproline (silaproline) group at the P2-equivalent position. Mass spectrometry (MS)-based assays demonstrate that silaproline-bearing nirmatrelvir derivatives efficiently inhibit isolated recombinant M, albeit with reduced potency compared to nirmatrelvir. Investigations with SARS-CoV-2 infected VeroE6 cells reveal that the silaproline-bearing inhibitors with a CF group at the P4-equivalent position inhibit viral progression, implying that incorporating silicon atoms into M inhibitors can yield in vivo active inhibitors with appropriate optimization. MS and crystallographic studies show that the nucleophilic active site cysteine residue of M (Cys145) reacts with the nitrile group of the silaproline-bearing inhibitors. Substituting the electrophilic nitrile group for a non-activated terminal alkyne shifts the inhibition mode from reversible covalent inhibition to irreversible covalent inhibition. One of the two prochiral silaproline methyl groups occupies space in the S2 pocket that is unoccupied in M:nirmatrelvir complex structures, highlighting the value of sila-derivatives in structure-activity-relationship (SAR) studies. The combined results highlight the potential of silicon-containing molecules for inhibition of M and, by implication, other nucleophilic cysteine enzymes.

Herein we report the development of an automated protocol for coupling aliphatic carboxylic acids and aryl halides under mild, electrochemical conditions. Carboxylic acids are one of the largest pools of commercially available building blocks utilized in parallel medicinal chemistry to expand structure-activity relationships. However, their usage in decarboxylative cross-coupling reactions to forge C(sp)-C(sp) bonds is low due to challenges associated with direct decarboxylation. Redox-active esters (RAE) are commonly employed to increase the reactivity of carboxylic acids for decarboxylative cross-coupling reactions. Previously, coupling reagent byproducts from in situ generated RAEs proved detrimental to transition metal catalysis. We have developed a purification-free protocol for activating carboxylic acids as N-hydroxyphthalimide (NHPI) esters, which are employed in electrochemical decarboxylative cross-coupling in a high-throughput, automated fashion. This automated workflow enables the preparation of compound libraries including PROTACs. By enabling the pool of commercial aliphatic carboxylic acids to be rapidly incorporated into drug-like molecules, this protocol can potentially impact how C(sp)-C(sp) cross-coupling reactions are performed in drug discovery campaigns.

RSK, or p90 ribosomal S6 kinase, plays a crucial role in tumor cell proliferation and survival, making it an appealing target for cancer therapies. With the aim to explore novel RSK inhibitors as anticancer agents, a series of 2,4-dianilinopyrimidine derivatives 2b-2n and 3a-3n have been designed and synthesized. Among them, compound 3e displayed substantial kinase inhibitory activity against RSK2 (IC = 37.89 ± 3.08 nM) and a potent antiproliferative effect against a range of cell lines, including HeLa, MIA PaCa-2, U937, SW620, HT-29, AGS, and two kinds of EGFR mutant cells (ICs = 0.189-0.572 μM). Additionally, compound 3e exhibited a high affinity for RSK and effectively inhibited RSK activity in HeLa cells. It triggered significant apoptosis and caused cell cycle arrest in the G2/M phase. Moreover, 3e displayed considerable in vivo anticancer activity while maintaining an acceptable safety profile. These findings imply that compound 3e, featuring a 2,4-dianilinopyrimidine scaffold, could serve as a promising RSK inhibitor for cancer treatment.

Stroke is a serious cerebrovascular disease that is categorized into two types: ischemic and hemorrhagic. The pathological mechanisms of ischemic stroke are complex and diverse, encompassing processes such as neuroinflammation and apoptosis. The pathological processes of hemorrhagic stroke primarily involve the disruption of the blood-brain barrier and cerebral edema. Western medical treatment methods show certain effectiveness during the acute phase of stroke, but they are limited by a narrow therapeutic window and secondary injuries. Traditional Chinese medicine (TCM) has a long history and unique advantages in treating stroke. Studies confirm that active compounds derived from TCM exert multi-pathway, multi-target effects, significantly improving therapeutic outcomes and reducing adverse reactions. However, due to the complexity of the components in TCM, research on monomeric components still faces challenges. This article reviews the relevant research progress published in domestic and international journals over the past twenty years regarding the mechanisms of action of monomeric components of TCM in the treatment of stroke, aiming to provide insights and references for the clinical application of TCM in stroke treatment and further new drug development.

The C-C chemokine receptor type 5 is a G protein-coupled receptor expressed on various immune cells, playing a crucial role in inflammation and chemotaxis. Beyond its physiological functions, C-C chemokine receptor type 5 is implicated in numerous diseases, including cardiovascular, central nervous system, immune system, and infectious diseases, as well as in the progression of cancer. The therapeutic potential of C-C chemokine receptor type 5 inhibition has been demonstrated by antagonists targeting the extracellular domain, notably maraviroc, a Food and Drug Administration-approved Human Immunodeficiency Virus entry inhibitor. However, challenges such as suboptimal pharmacokinetics and efficacy necessitate new antagonists with unique modes of action. Recent advancements in G protein-coupled receptor structural characterization have identified a novel intracellular allosteric binding site in chemokine receptors. This study introduces a series of disubstituted [1,2,5]oxadiazolo-[3,4-b]pyrazines targeting the intracellular allosteric binding pocket of C-C chemokine receptor type 5. Among these, compound 3ad emerged as a promising C-C chemokine receptor type 5-selective allosteric antagonist with a half-maximal inhibitory concentration of 1.09 μM and an almost 30-fold selectivity over C-C chemokine receptor type 2. Molecular dynamics simulations and a competition assay with a Gα mimetic were used to confirm the intracellular binding mode of these compounds. This novel class of C-C chemokine receptor type 5-selective intracellular antagonists offers a foundation for developing molecular tools and therapeutic agents, potentially overcoming the limitations of current extracellular C-C chemokine receptor type 5 antagonists.

Adamantyl-based compounds have been successful clinically for the treatment of neurological disorders and viral infections. Whilst the effects of incorporating adamantane into a drug scaffold is contextual by nature, its unique structural and physicochemical properties have attracted considerable attention. Previous reviews have highlighted its ability to alter physicochemical properties such as lipophilicity. However, with the movement to incorporate structural complexity and escape the 'flat land' of modern drug discovery, adamantane provides value beyond a hydrophobic substituent. The non-planar three-dimensional rigid scaffold allows for the precise positioning of substituents to probe drug targets more effectively. This review evaluates the synthetic accessibility and subsequent integration of multi-substituted and hetero-adamantane containing ligands in drug discovery programs. The vast benefits of adamantyl-based motifs beyond increasing the lipophilicity of a target compound are discussed thus emphasising its multi-dimensional value in drug discovery.

Salinomycin (SAL), a natural polyether ionophore, exhibits a broad spectrum of pharmacological activities, including potent anticancer activity. Over the past decade, much effort has been put into developing methods for rational chemical modification of SAL to obtain semisynthetic analogs with higher anticancer activity than the native structure. In this paper, we describe an optimized procedure for synthesizing C20-aminosalinomycin 2 with native stereochemistry at position C20, which was confirmed by single-crystal X-ray diffraction analysis. We further transformed amine precursor 2 into a series of 48 C20-N-(thio)acylated products, including N-(sulfon)amides, N-(thio)ureas, and N-carbamates (urethanes), along with their sulfur analogs, i.e., S-substituted thiocarbamates and dithiocarbamates. This previously unreported class of derivatives showed superior cytotoxicity mostly in the nano- and subnanomolar concentration range and improved selectivity toward human cancer cells compared to those of chemically unmodified SAL and a commonly used oncological drug cisplatin. Of note, the obtained products inhibited the proliferation of reference cancer cells more effectively than their C20-epi-N-acylated counterparts, pointing out the pivotal role of stereochemistry at position C20. Our findings support the premise that the modification of SAL is a fruitful strategy for products with promising biological activity profiles. Moreover, the straightforward protocols should be of significant value for more elaborate modifications of SAL in the future.

Artemisinin combination therapies (ACTs) are critical components of malaria control worldwide. Alarmingly, ACTs have begun to fail, owing to the rise in artemisinin resistance. Thus, there is an urgent need for an expanded set of novel antimalarials to generate new combination therapies. Herein, we have identified a 1,2,4-triazole-containing carboxamide scaffold that, through scaffold hopping efforts, resulted in a nanomolar potent deuterated picolinamide (110). The lead compound of this class (110) displays moderate aqueous solubility (13.4 μM) and metabolic stability (CLint HLM 17.3 μL/min/mg) in vitro, as well as moderate oral bioavailability (%F 16.2) in invivo pharmacokinetic studies. Compound 110 also displayed activity against various P. falciparum isolates with different genetic backgrounds and a slow-to-moderate rate of killing (average parasite reduction ratio 2.4), making the series appealing for further development.

Androgen receptor (AR) antagonists are the first-line medicine for the treatment of prostate cancer (PCa) in clinic. In our previous work, the tetrahydroquinoline derivative AT2 was identified as a novel scaffold AR antagonist via virtual screening and structural modifications, while its poor pharmacokinetic properties hindered further development. Herein, we report the systematic structural optimizations of AT2 and discover a novel tetrahydroquinoline derivative C2 as potent AR antagonist with an IC value of 0.019 μM, accompanied with excellent selectivity over other nuclear receptors (PR, GR, MR). Further biological assays revealed that C2 significantly inhibited LNCaP cell proliferation, and efficiently reduced PSA protein expression. Especially, C2 showed superior efficacy against AR mutants compared to darolutamide and enzalutamide. Furthermore, C2 demonstrated excellent oral bioavailability, indicating the potential to enhance in vivo efficacy and to serve as a promising therapeutic option for PCa treatment.

Simultaneously modulating the glutamatergic and monoaminergic systems represents a promising strategy for treating depression. In this study, a series of multi-target antagonists targeting both NMDAR and monoamine transporters (SERT, DAT, and NET) was designed and evaluated for their antidepressant potential in vitro and in vivo. Among these heterocycle-fused phenylcyclohexylamine derivatives, compound A16 demonstrated potent and relatively balanced multi-target activity (A16: IC(NMDAR): IC(SERT): IC(DAT): IC(NET) = 1.8:1.0:1.9:1.3) compared to the lead compound S1. Pharmacokinetic studies revealed that A16 exhibited moderate clearance in microsomes and favorable oral brain exposure in mice. In vivo assessments showed that A16 and its R-isomer A17 exhibited significant antidepressant-like effects in the forced swim test and tail suspension test in mice. Notably, A17 demonstrated significant antidepressant-like effects at doses as low as 1 mg/kg, with no indication of addiction risk at 20 mg/kg. Collectively, these findings identify A17, a heterocycle-fused phenylcyclohexylamine as a promising scaffold for developing non-addictive, rapid-acting antidepressants.

In this study, we have developed a new category of antihypertensive agents using copper-catalysed "click chemistry". This series of six hybrid compounds (HRa-f) consists of quinazoline-(3H)-one-1,2,3-triazole-acetamide derivatives. In order to confirm their structures, they were characterised by a number of techniques including infrared spectroscopy, proton and carbon nuclear magnetic resonance, heteronuclear multiple bond correlation, heteronuclear single quantum coherence and correlation spectroscopy. X-ray diffraction analysis and interactions, including hydrogen bonding which stabilises the crystal lattice, have been studied. Analyses of the Hirshfeld surface mapped to di, de, dnorm and shape index were used to detect intermolecular interactions. The histogram of the fingerprints shows that the H⋯H (48.2 %) and O⋯H (12.6 %) contacts are the dominant interactions in the crystal stacking. The vasorelaxant activity of the synthesised compounds was evaluated using aortic rings from precontracted rats exposed to epinephrine (10 μM). Dose-response studies indicated that the vasorelaxant efficacy varied depending on the structural modifications of the drugs. Molecular docking studies were also performed to predict binding affinity and identify the most likely binding interactions between the hybrid molecules and the calcium channel. Cav 1.2, the alpha-subunit containing key binding sites (EEE locus: GLU 363, GLU 706, GLU 1135, GLU 1464), was compared with the drug verapamil. Docking results confirmed that verapamil (-8.22 kcal/mol) was the most potent compound, followed by the HRa-f compounds.

Neurodegenerative disorders, such as Parkinson's disease and Alzheimer's disease, constitute pathological conditions of great relevance on health span and quality of life. The identification of novel therapeutic options, able to modulate the processes involved in the insurgence and progression of neurodegenerative disorders, represents an intriguing challenge of current research. Herein, a library of 36-membered 2-(phenylamino)-7,8-dihydroquinazolinone derivatives was synthesized and biologically evaluated as human MAO inhibitors. Some compounds able to inhibit MAO-B potently and selectively (K in the nanomolar range) were identified, and robust structure-activity relationships were drawn, supported by computational studies. Further biological assays revealed a safe profile for all derivatives and, for compounds selected as the best MAO-B inhibitors (4, 5, 13, 14) the following properties also emerged: (i) the ability to inhibit MAO-B activity in whole cells, with an effectiveness comparable or slight lower with respect to the reference safinamide; (ii) physicochemical parameters suggesting drug-likeness properties; (iii) the ability to inhibit, albeit weakly, GSK3β kinase (for compound 4). Within the whole series, compound 4 stood out as a promising lead for future optimization campaigns aimed to obtain useful drugs for the treatment of Alzheimer's and Parkinson's diseases.

Acute respiratory diseases in humans can be caused by various viral pathogens such as respiratory syncytial virus (RSV), human coronavirus 229E (hCoV-229E), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To prevent severe cases by an early treatment, one effective strategy is to inhibit viral infection at the entry stage of the replication cycle. However, there is a lack of efficient, FDA-approved small-molecule drugs targeting these pathogens. Previously, we identified two dual RSV/hCoV-229E small-molecule inhibitors with activity in the single-digit micromolar range. In this study, we focused on a structure-guided optimization approach of the more promising prototype addressing activity, cell viability, selectivity, solubility and metabolic stability. We present valuable insights into the structure-activity relationship (SAR), and report the discovery of a sub-micromolar RSV entry inhibitor, a dual RSV/CoV-229E inhibitor and a highly potent compound against hCoV-229E.