In continuation of our interest in fluorinated chalcones with promising bioactivities, four 2,3-dihydroxychalcones named Non-F, 3-F, 4-F and 3,4-diF were screened for their α-glucosidase inhibitory activity. All tested four compounds exhibited better inhibitory activities than the positive reference control, acarbose (IC50 = 69.582.04 µM). Remarkably, compounds 3,4-diF (IC50 = 5.340.11 µM) and 3-F (IC50 = 6.840.33 µM) demonstrated more than 10-fold greater potency in α-glucosidase inhibition than acarbose in our assay. Intrinsic fluorescence quenching measurements revealed that the inhibitors directly bind to α-glucosidase. The fluorescence intensity of [α-glucosidase/8-anilino-1-naphthalenesulfonic acid (ANS)] complexes was quenched upon addition of inhibitors, indicating hydrophobic contacts between enzyme and fluorinated chalcones. Furthermore, the Lineweaver-Burk plots were applied to determine the inhibition mechanisms of chalcones against α-glucosidase. For the first time, it was found that Non-F, 4-F and 3,4-diF are competitive inhibitors, whereas 3-F acts as a non-competitive inhibitor.

Chain-length matters: How benzylalkyldimethylammonium quaternary disinfectants disrupt gonadal steroidogenesis via 3β-hydroxysteroid dehydrogenase inhibition.

Discovery of 1-(4-cyanopyrimidin-2-yl)-1H-pyrazole-4-carboxylic acids as potent xanthine oxidase inhibitors via molecular cleavage and reassembly of allopurinol as a key strategy.

Environmental pyridinium disinfectants impair cortisol metabolism via 11β-hydroxysteroid dehydrogenase 2 inhibition: A cross-species risk evaluation.

A potent and selective RORγ inhibitor for the treatment of autoimmune diseases.

Design and synthesis of dual-activity biphenyl inhibitors against SARS-CoV-2 and bladder cancer.

In-vitro and in-vivo CYP3A4 Variants: Neratinib metabolism and drug interaction risk.

Elucidating the potential of novel class biphenyl-phenyl acetate, IDD-AN-A1, an inhibitor targeting Isocitrate Lyase in Mycobacterium tuberculosis: A target to lead approach.

Synthesis of new Pyridazinone derivatives and their dual inhibitory activity on aldose reductase and α-glucosidase.

Roles of full-length and Δα1 HLA-G isoforms in NK-cell regulation and vascular SARS-CoV-2 infection.

The binding of human growth hormone (hGH) to the human growth hormone receptor (hGHR) is a key endocrinological process that controls critical aspects of cell growth, proliferation and differentiation. Mechanistically, this sequential, asymmetric binding event involves the interaction between a single hGH molecule and distinct sites (site 1 and site 2) on the extracellular domain of a preformed hGHR homodimer. Our group recently identified S1H, a rationally-designed peptide sequence mimetic of the hGH site 1-binding helix (residues 36-51) that disrupts the hGH-hGHR interaction and inhibits hGH-mediated phosphorylation of signal transducer and activator of transcription 5 (STAT5) in hGHR-positive cell lines. Structure-activity relationship studies revealed a positive correlation between helical propensity and inhibitory potency of the S1H peptide, prompting the design of structurally "stabilized" S1H variants (SS1H) with improved biological activity. In this study, we employed a chemical strategy, termed hydrocarbon stapling, to generate a series of SS1H peptides that proved to be more helical, proteolytically stable and biologically active compared to linear (unstructured) S1H. Notably, one SS1H derivative (SS1HB) inhibited hGH-induced STAT5 phosphorylation in hGHR-positive human bladder cancer cells more effectively than pegvisomant, the only hGHR antagonist currently approved by the FDA. Collectively, our results demonstrate that hydrocarbon stapling improves the antagonistic effects of S1H peptides and elevates their potential as chemical probes to study the molecular mechanisms of hGH signaling. It is also anticipated that SS1H peptides will serve as potent lead compounds for developing next-generation therapeutics designed to treat endocrine disorders that manifest along the hGH-hGHR signaling axis.

The α9α10 nicotinic acetylcholine receptor (nAChR) is a promising therapeutic target for neuropathic pain. In this work, we report the discovery of a monodisulfide-bridged conotoxin from a transcriptome database that acts as a potent pore blocker of the α9α10 nAChR. Structure-activity relationship studies yielded a peptide analogue with ∼2-fold increase in inhibitory potency (IC50 ≈ 17 nM vs 32 nM for wild-type Qc-037) and dramatically improved subtype selectivity: both [M16R] and [F19R] exhibited ∼100-fold selectivity for α9α10 over α7 nAChR and ∼50- to 100-fold selectivity over α4β2 nAChR. In a rat model of oxaliplatin-induced cold allodynia, the optimized analogues M16R and F19R exhibited pronounced in vivo analgesic efficacy. This study not only identifies a novel mechanistic class of α9α10 nAChR inhibitor but also provides promising lead compounds for treating chemotherapy-induced neuropathic pain.

The rising antimicrobial resistance leads to the need to develop new antimicrobial scaffolds. DNA gyrase is a vital, bacteria-specific enzyme, a prime target for the discovery of new antibiotics. The potential anti-DNA gyrase potency of some pyrazolo[1,5-a]pyrimidine-based 2-arylthiazolidin-4-ones 1 was examined. These products were obtained herein, in 77-94% yields, by reacting a mixture of the proper amines, benzaldehydes, and thioglycolic acid in refluxing ethanol for 5–6 h containing 20 mol% para-toluenesulfonic acid. Hybrids 1d and 1k, attached to 4-nitrophenyl units at thiazolidinone-C2, displayed comparable potency to ciprofloxacin with MIC/MBC of 1.77/3.53 and 1.39/2.79 µM, respectively, against S. aureus and MIC/MBC of 2.82/5.65 and 2.23/4.45 µM, respectively, against E. faecalis and P. aeruginosa. 1d and 1k demonstrated promising anti-MRSA potency with MIC/MBC of 3.53/14.13 and 2.79/11.15 µM, respectively, and significant S. aureus DNA gyrase inhibitory activity, with IC50 of 1.78 and 1.52 μM, respectively.

Abstract Three novel phosphor/thiophosphor-amides, [(5-CH 3 )- 2 Py-NH] 2 [C 6 H 11 (CH 3 )N]P(X) (X = O ( 1 ) and S ( 2 )) and [(5-CH 3 )- 2 Py-NH]P(O)[OCH 2 C(CH 3 ) 2 CH 2 O] ( 3 ), were synthesized and characterized by FT-IR and 1 H/ 13 C/ 31 P-NMR spectroscopy. The structures of 1 and 3 were determined by using single-crystal X-ray diffraction (SC-XRD) crystallography which reveals both compounds to crystallize in monoclinic space groups ( P 2 1 / c and P 2 1 / n , respectively). A crystal packing analysis shows that neighbouring molecules are connected together via N–H⋯O═P hydrogen bonds forming one-dimensional chains. A Hirshfeld surface analysis indicates that crystal packing is dominated by H⋯H, H⋯O/O⋯H, H⋯C/C⋯H, and H⋯N/N⋯H contacts, with O⋯H/H⋯O interactions including the classical N–H⋯O═P hydrogen bonds being particularly favored. Phosphor/thiophosphor-amide derivatives are emerging as promising scaffolds for targeting key enzymes of acetylcholinesterase (1EEA, 5FPP) and urease (2UBP, 4GY7). Molecular docking revealed favorable binding affinities (up to −10.3 kcal/mol for 1 with 1EEA), with compounds 1 and 2 generally exhibiting stronger predicted interactions than compound 3 . Key stabilizing interactions involve phosphoryl/thiophosphoryl groups and pyridine rings. Redocking of co-crystallized ligands with RMSD assessment confirmed the reliability of the docking protocol. While these results do not provide definitive evidence of inhibitory potency, they support further computational refinement and experimental evaluation, highlighting the potential of these derivatives as enzyme-interacting agents with biomedical relevance.

Targeted modulation of enzyme activity offers a promising strategy for both elucidating catalytic mechanisms and developing novel therapeutics. In this study Zn2+ ions were introduced as an effective competitive inhibitor of fumarase, a pivotal enzyme in the citric acid cycle. Zn2+ binding significantly alters the Michaelis constant (Km) for both L-malate and fumarate, with a pronounced preference for inhibiting the reverse reaction (L-malate to fumarate), a direction relevant to redox homeostasis and anaplerotic flux. A major limitation of the clinical application of many metal-based inhibitors is their poor water solubility. To overcome this challenge and introduce a new class of enzyme inhibitors, zinc-modified carbon quantum dots (Zn-CQDs) were synthesized. Owing to their polar surface, Zn-CQDs interact more effectively with the enzyme, which increases the local concentration of Zn2+ ions at the active site. As a result, these nanomaterials exhibit enhanced water solubility and significantly greater inhibitory potency compared to free Zn2+ ions. Biophysical and kinetic analyses confirmed the competitive inhibition mechanism and demonstrated that Zn-CQDs interact with the enzyme without perturbing its secondary structure. Notably, both Zn2+ ions and Zn-CQDs preferentially inhibited the reverse reaction of fumarase, offering precise control over fumarase activity. Molecular docking and MD simulations elucidated the plausible binding site of Zn2+ within the active site. It was found that Zn2+ interacts with Glu340, a residue previously shown to be involved in binding fumarase inhibitors. These findings establish Zn-CQDs as a novel class of water-soluble fumarase inhibitors, distinguished by their facile synthesis, tunable solubility, and selective inhibition profile. This work highlights the potential of zinc-based nanomaterials in enzyme regulation, offering a powerful alternative to existing inhibitors and developing targeted redox-sensitive therapeutic strategies.

Although immune checkpoint inhibition has emerged as a promising treatment for many solid tumors, infiltrating immune cells, such as tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs), can limit their potencies. To address this issue, we used folic acid to target a Toll-like receptor 7 (TLR7) agonist to folate receptor β (FRβ) expressing TAMs and MDSCs, with the anticipation that repolarization of these myeloid cells to tumoricidal phenotypes might restore the intrinsic potencies of checkpoint inhibitors. We demonstrate that this folate-TLR7 conjugate can not only reprogram FRβ-expressing myeloid cells in the tumor microenvironment (TME) but can also induce a global shift in the TME to an inflammatory state. We then demonstrate that TME repolarization significantly enhances the potencies of both anti-PD-1 and anti-CTLA-4 checkpoint inhibitors in multiple tumor models and conclude that the reprogramming of TAMs/MDSCs to a tumoricidal phenotype can significantly augment the potencies of checkpoint inhibitors without causing toxicity to healthy tissues.

Matrix metalloproteinase-9 (MMP-9) is a zinc-dependent enzyme that degrades the extracellular matrix and is involved in various diseases, including rheumatoid arthritis, atherosclerosis, tumor invasion, and metastasis. Despite the development of inhibitors, none have succeeded in trials. Our goal was to find potential inhibitors to regulate its proteolytic activity. Ligand- and structure-based drug design approaches were explored to identify inhibitors against wild-type (1GKC) and mutant (2OW1) MMP-9. A pharmacophore model was created, and drug-like molecules were prioritized to guide the development of benzamide and 1H-indole-2-carboxamide derivatives. These compounds were synthesized and characterized using ¹H NMR, 13C NMR, and HRMS (ESI). An experimental evaluation assessed their inhibitory potential and IC50 values against MMP-9. Most tested inhibitors fit the pharmacophore model, which consists of three aromatic/hydrophobic spheres and two hydrogen-bond donors/acceptors. Compounds 1, 2, 8, 10, 20, 21, 27, and 29 exhibited significant inhibition (P < 0.0001) of over 60%. Compounds 2 and 20 inhibited growth by over 70%, with IC50 values of 28.59 μM and 30.82 μM, respectively. The IF docking showed strong binding for these, with scores of -9.179 and -10.739 kcal/mol. The alignment between the computational approach and experimental validation reinforces the inhibitor's specificity and potency, confirms the docking model, and suggests that the predicted binding pose represents key biological interactions.

Glutathione S-transferases (GSTs) are multifunctional enzymes involved in the metabolism of a wide variety of xenobiotics and endogenous compounds. Since some GST isozymes are overexpressed in a variety of malignancies and have been shown to play roles in the development of drug resistance, GSTs have become a promising therapeutic target. Although numerous natural and plant-derived compounds have been evaluated as GST inhibitors, the interaction between human GSTP1-1 and auxins-indole-derived plant hormones that are also detectable in human biological systems-has not been previously characterized. The present study aimed to investigate whether selected auxins can modulate the activity of human placental GSTP1-1 (hpGSTP1-1) and to elucidate the mechanistic and structural basis of any interactions. The inhibitory effects of indole-3-acetic acid (IAA), indole-3-propionic acid (IPA), and indole-3-butyric acid (IBA) on hpGSTP1-1 were evaluated using in vitro enzyme kinetic assays. IC50 determination was conducted at various auxin concentrations. Subsequently, through inhibitory kinetic studies, the inhibition types and kinetic parameters were determined. In parallel, molecular docking was performed to provide structural insight into interactions between hpGSTP1-1 and auxins. All three auxins inhibited hpGSTP1-1 activity in a concentration-dependent manner, with IC50 values of 7.9mM (IAA), 6.5mM (IPA), and 4.2mM (IBA). Kinetic analyses revealed competitive inhibition with respect to both substrates. The Ki values from statistical analysis/secondary plots for IAA, IPA, and IBA at [CDNB]f-[GSH]v and at [GSH]f-[CDNB]v were 4.00 ± 0.62mM/2.38mM; 3.33 ± 0.23mM/2.84mM; 3.33 ± 0.22mM/2.61mM and 3.30 ± 0.24mM/2.38mM; 3.52 ± 0.24mM/2.84mM; 2.14 ± 0.16mM/2.61mM, respectively. These inhibitory auxins were thought to be held mainly by the hydrophilic amino acid residues that are located at the glutathione-binding site of the enzyme. This study provides a biochemical and structural characterization of weak, competitive inhibition of hpGSTP1-1 by auxins based on combined in vitro and in silico analyses. While the inhibitory potency is limited and unlikely to be pharmacologically relevant at physiological concentrations, the combined in vitro and in silico findings offer valuable mechanistic and structural insight into auxin-GSTP1-1 interactions.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that leads to gradual deterioration of cognitive functions. Cholinesterase enzymes play a critical role in regulating acetylcholine levels in the brain, and their dysfunction leads to impaired cholinergic neurotransmission, which is a primary hallmark of AD and contributes significantly to the cognitive decline and dementia. Here, a series of pyrazine-1,2,3-triazole molecular hybrids incorporating a trifluoromethyl (-CF3) group were synthesized (8a-o). Synthesized compounds were then evaluated in vitro for cytotoxicity and cholinesterase inhibitory activities. All synthesized compounds were found to be nontoxic toward BV-2 cells in the cytotoxicity screening. The in vitro inhibition assays revealed that these derivatives exhibited greater inhibitory potency against acetylcholinesterase (AChE) than butyrylcholinesterase (BuChE). Among them, compound 8h demonstrated the most potent AChE inhibition compared to BuChE (AChE, IC50 = 5.43 µM; BuChE, IC50 = 127.12 µM). The most active compound 8h was further subjected to molecular docking and dynamic simulation (100 ns) to investigate its binding affinity, thermodynamic behavior, and stability within the active site of cholinesterase enzymes. Overall, the findings suggested that the synthesized compounds represent promising drug candidates as selective acetylcholinesterase inhibitors for the treatment of AD.

Due to the limited size of viral genomes, most viral proteins are multifunctional; yet most direct-acting antivirals are designed as single-function inhibitors. The dengue virus (DENV) capsid protein serves as a building block for new virions while also interacting with multiple host factors to remodel the cellular environment. Using established capsid inhibitor ST148 as a targeting ligand, we develop a DENV capsid degrader, RPG-01-132, that exhibits a broadened spectrum of activity against the four DENV serotypes and an ST148-resistant mutant virus. Using multiple approaches, we show that RPG-01-132's sub-micromolar antiviral activity is due to CRL4CRBN-dependent degradation of capsid and that this mechanism disrupts capsid-related pathways required for productive infection, including infectious virus output and capsid-mediated antagonism of the interferon response. This pharmacology is well-differentiated from ST148, which interferes with assembly of new virions, but has no demonstrated effect on the capsid's nonstructural functions. These findings demonstrate that targeted protein degradation can thus enable antiviral pharmacology not observed with conventional antiviral inhibitors andthat isresilient to point mutations that reduce inhibitor potency.