Membrane proteins, a principal class of drug targets, play indispensable roles in various biological processes and are closely associated with essential life functions. Their study, however, is complicated by their low solubility in aqueous environments and distinctive structural characteristics, necessitating a suitable native-like environment for molecular analysis. Nanodisc technology has revolutionized this field, providing biochemists with a powerful tool to stabilize membrane proteins and significantly enhance their research possibilities. This review outlines the substantial advancements in nanodisc methodologies and applications from 2018 to 2024. We cover the development of various nanodisc models, as well as structural and functional studies of membrane proteins that utilize nanodiscs, highlighting their medical applications.

Quaternary ammonium compounds (QACs) play crucial disinfectant roles in healthcare, industry, and domestic settings. Most commercially utilized QACs like benzalkonium chloride have a common architectural theme, leading to a rise in bacterial resistance and urgent need for novel structural classes. Some potent QACs such as chlorhexidine (CHX) and octenidine (OCT) feature a bolaamphiphilic architecture, comprised of two cationic centers at the molecular periphery and a non-polar region connecting them; these compounds show promise to elude bacterial resistance mechanisms. Inspired by such structures, we synthesized a series of 43 biscationic amphiphilic compounds focused on a resorcinol core, featuring flexibility of linker lengths, alkyl tails, and relative substituent positioning, to study their structure activity relationships (SARs). Antibacterial activity evaluation against a panel of gram-positive and gram-negative strains, including ESKAPE pathogens (A. baumannii, P. aeruginosa), were encouraging, with minimum inhibitory concentrations (MICs) of 0.5-4 μM against all tested strains for select compounds. Ten prepared compounds bearing either 17 or 18 total side chain carbons demonstrated uniformly strong antibacterial activity against P. aeruginosa (MIC 4-16 μM) and 6 other strains (MIC ≤4 μM), irrespective of cationic spacing. These findings promise to further extend the application of bolaamphiphilic QACs as a novel class of disinfectants.

After more than 15 years of decline, the Malaria epidemy has increased again since 2017, reinforcing the need to identify drug candidates active on new targets involved in at least two biological stages of the Plasmodium life cycle. The SUB1 protease, which is essential for parasite egress in both hepatic and blood stages, would meet these criteria. We previously reported the structure-activity relationship analysis of α-ketoamide-containing inhibitors encompassing positions P4-P2'. Despite compounds with high inhibitory potencies were identified, their antiparasitic activity remained limited, probably due to insufficient cell permeability. Here, we present our efforts to improve it through the N-terminal introduction of basic or hydrophobic moieties and/or cyclization. Compared to our previous reference compounds 1/2 (Ac-Ile/Cpg-Thr-Ala-AlaCO-Asp-Glu(Oall)-NH2), we identified analogues with improved Pf-/PvSUB1 inhibition (IC50 values in the 10-20 nM  range) and parasite growth inhibition (up to 98% at 100 μM). The increase in potency was mainly observed when increasing the overall hydrophobicity of the compounds. Conjugation to the cell penetrating peptide octa-arginine was also favorable. Finally, the crystal structure of PvSUB1 in complex with compound 15 has been determined at 1.6 Å resolution. Compared to compound 1, this structure extended to the P5 residue and revealed two additional hydrogen bonds.

Presented herein is the chemical construction of unprecedented 3,4-trans-3,6-anhydro hexofuranose frameworks. The disfavored 3,6-anhydro hexofuranosides were effectively established by Pd-catalyzed debenzylative intramolecular acetalation for the first time. The critical roles of benzyl protection and Pd as catalyst were demonstrated. Various 3,4-trans-3,6-anhydro sugars including sauropunol E was first obtained in satisfactory yields. Pharmaceutical investigation of the sauropunol E and its analogues revealed their potential application as anti-inflammatory agents.

As a newly emerging technology, conformational engineering (CE) has been gradually displaying the power of producing protein-like nanoparticles (NPs) by tuning flexible protein fragments into their original native conformation on NPs. But apparently, not all types of NPs can serve as scaffolds for CE. To expedite the CE technology on a broader variety of NPs, the essential characteristic of NPs as scaffolds for CE needs to be identified. Herein, we investigate the potential of two distinct types of NPs as scaffolds for CE: CdSe/ZnS quantum dots (QDs), an ionic compound NP, and palladium NPs (PdNPs), a metal NP. The results demonstrate that while QDs cannot support the restoration of the native conformation and function of the complementary-determining region (CDR) fragments of antibodies, PdNPs can. The notably disparate outcomes unequivocally show that the mobility of the surface atoms/adatoms of the NPs or the mobility of the conjugating bonds to the NPs is essential for CE, which allows the conjugated peptides to undergo a conformational change from their initial random conformation to their most stable native conformation under the constraints mimicking the native long-range interactions in the original proteins. This discovery opens the door for CE on more NPs in the future.

A key molecular dysfunction in heart failure is the reduced activity of the cardiac sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) in cardiac muscle cells. Reactivating SERCA2a improves cardiac function in heart failure models, making it a validated target and an attractive therapeutic approach for heart failure therapy. However, finding small-molecule SERCA2a activators is challenging. In this study, we used a machine learning-based virtual screening to identify SERCA2a activators among 57,423 natural products. The machine learning model identified ten structurally related natural products from Zingiber officinale, Aframomum melegueta, Alpinia officinarum, Alpinia oxyphylla, and Capsicum(chili peppers) as SERCA2a activators. Initial ATPase assays showed seven of these activate SERCA at low micromolar concentrations. Notably, two natural products, Yakuchinone A and Alpinoid D displayed robust concentration-dependent responses in primary ATPase activity assays, efficient lipid bilayer binding and permeation in atomistic simulations, and enhanced intracellular Ca2+ transport in adult mouse cardiac cells. While these natural products exert off-target effects on Ca2+ signaling, these compounds offer promising avenues for the design and optimization of lead compounds. In conclusion, this study increases the array of calcium pump effectors and provides new scaffolds for the development of novel SERCA2a activators as new therapies for heart failure.

Multicomponent reactions have long been recognized as some of the most versatile tools in organic chemistry, with extensive applications in biomedical science and the pharmaceutical industry. In this study, we explored the potential of the Passerini reaction by designing and synthesizing new low molecular mass gelators that can serve as novel formulations for prolonged anesthesia. These gelators address critical issues like poor solubility, low bioavailability, and short plasma half-life, all of which hinder therapeutic efficacy. To further understand the gelation mechanism, we performed density functional theory (DFT) calculation for confirming the presence of non-covalent interactions during gel formation. Additionally, we evaluated the antimicrobial properties of the synthesized compounds, aiming to counter the rise of infectious diseases. These innovative antimicrobial agents could offer solutions to the growing problem of antibiotic resistance, which renders many existing therapies ineffective. Overall, this study aims to develop advanced formulations and antimicrobial agents through the Passerini reaction, providing new strategies for treating infections, minimizing side effects, and combating antibiotic resistance.

For decades quaternary ammonium compounds (QACs) have served as main component of a top antiseptic and disinfectant compositions. Among them, bis-QACs are the most prominent and effective class of biocides. Although mono-QACs still dominate the antiseptic market, their activity against Gram-negative bacteria is largely inferior to bis-QACs. Moreover, the new wave of bacterial resistance during the COVID-19 pandemic is threatening the efficiency of popular antiseptics. Therefore, the requirement for novel biocides is urgent. Reported here is a unified and simple two-step synthesis to achieve novel biocide's architectures with aromatic linkers. Thus, a series of 14 bis-QACs have been prepared using an Ullman-type reaction following by N-alkylation. The most prominent compounds showed strong bioactivity against a panel of nineteen microbial pathogens, multi-resistant bacterial ESKAPEE strains, fungi and biofilms, including strains, which acquired resistance during COVID-19 in 2021. Moreover, significant improvements in antibiofilm action were observed, where bis-QACs 5c and 6a outperformed gold standard pyridinium antiseptic octenidine. These findings will serve as a good basis for further studies of bis-QACs architectures as highly effective biocides.

The development of novel therapeutic strategies enabling the selective destruction of tumors while sparing healthy tissues is of great interest to improve the efficacy of cancer chemotherapy. In this context, we designed a β-glucuronidase-responsive albumin-binding prodrug programmed to release a potent Isocombretastatin A-4 analog within the tumor microenvironment. When injected at a non-toxic dose in mice bearing orthotopic triple-negative mammary tumors, this prodrug produced a significant anticancer activity, therefore offering a valuable alternative to the systemic administration of the parent drug.

The serine/threonine protein kinase CK2, a tetramer composed of a regulatory dimer (CK2β2) bound to two catalytic subunits CK2α, is a well-established therapeutic target for various pathologies, including cancer and viral infections. Several types of CK2 inhibitors have been developed, including inhibitors that bind to the catalytic ATP-site, bivalent inhibitors that occupy both the CK2α ATP-site and the αD pocket, and inhibitors that target the CK2α/CK2β interface. Interestingly, the bivalent inhibitor AB668 shares a similar chemical structure with the interface inhibitor CCH507. In this study, we designed analogs of CCH507 using structure-based and fragment-based approaches. The ability of these analogs to bind the CK2α/CK2β interface was evaluated using biolayer interferometry and fluorescence anisotropy-based assays. Their potency to inhibit CK2 kinase activity was determined using the bioluminescent ADP-Glo assay. These experiments allowed us to investigate which chemical modifications prevent the binding of the compounds at the CK2α/CK2β interface. Seven out of sixteen compounds conserved the ability to bind at the protein-protein interface, among which three compounds exhibited better interface inhibition compared to CCH507.

The SH2-containing inositol phosphatase (SHIP) has become an actively researched therapeutic target for a number of disorders, including Alzheimer's Disease, Graft-vs-Host disease, obesity and cancer. Analogs of the aminosteroid SHIP inhibitor 3a-aminocholestane (3AC) have been synthesized and tested. Analogs with improved water solubility have been identified. Deletion of the C17 alkyl group from the cholestane skeleton improves water solubility, however these compounds inhibit both SHIP1 and SHIP2. Enzyme kinetics imply that these molecules are competitive inhibitors of SHIP, binding at a site near where the substrate binds to the phosphatase. A model of the binding of the inhibitors within the active site of SHIP1 is proposed to explain the structure activity studies. Overall this work provides more water soluble aminosteroid pan-SHIP1/2 inhibitors that can be used for future studies of SHIP activity.

In this study, we analyzed publicly accessible data related to the Staphylococcus aureus NorA protein, a well-known efflux pump involved in antimicrobial resistance. Our analysis revealed several inconsistencies in data annotation, and significant issues concerning the homogeneity across datasets, which compromise the reliability of data-driven approaches aimed at identifying novel Staphylococcus aureus NorA efflux pump inhibitors (EPIs). To address these challenges, we propose a standardized pipeline for experimental procedures and data annotation, designed to enhance the consistency and quality of EPI datasets submitted to repositories, thereby increasing the utility of publicly available datasets for the discovery of potential EPIs. By implementing this framework, the findings reported herein aim to foster more reliable and reproducible research outcomes in drug discovery projects targeting NorA or other efflux pumps.

Tuberculosis remains a leading global health threat, exacerbated by the emergence of multi-drug-resistant strains. The search for novel therapeutic agents is critical in addressing this challenge. This review systematically summarizes the potential of oxadiazole derivatives as promising candidates in antimycobacterial drug discovery. We focus on various classes of oxadiazoles, especially 1,2,3-oxadiazoles, 1,2,4-oxadiazoles, and 1,2,5-oxadiazoles, highlighting their structural diversity and biological activities. Recent advancements in structure-activity relationship studies are discussed, emphasizing the mechanisms of antimycobacterial action. Additionally, the synergistic potential of 1,2,4-oxadiazoles in enhancing the efficacy of existing tuberculosis treatment with ethionamide is also discussed. By integrating insights from recent research, this review aims to provide a comprehensive overview of the role of oxadiazoles in the fight against tuberculosis, paving the way for future investigations and the development of effective therapeutic strategies.

Cofactors are non-protein entities necessary for proteins to operate. They provide "functional groups" beyond those of the 20 canonical amino acids and enable proteins to carry out more diverse functions. Such a viewpoint is rarely mentioned, if at all, when it comes to natural products and is the theme of this Concept. Even though the mechanisms of action (MOA) of only a few natural products are known to require cofactors, we believe that cofactor mediated MOA in natural products are far more prevalent than what we currently know. Bleomycin is a case in point. It binds iron cation to form a pseudoenzyme that generates reactive oxygen species. As another example, calcium cations induce laspartomycin to "fold" into the active conformation. Iron and calcium are bona fide cofactors for bleomycin and laspartomycin, respectively, as these natural products do not display their characteristic anticancer and antibacterial activities without Fe(II) and Ca(II). These types of cofactor mediated MOA in natural products were discovered mostly serendipitously, and being conscious of such a possibility is the first step toward identifying more novel chemistry that nature performs.

The breast cancer resistance protein (BCRP/ABCG2) plays a major role in the multidrug resistance of cancers toward chemotherapeutic treatments. It was demonstrated that cholesterol regulates the ABCG2 activity, suggesting that lower levels of membrane cholesterol decrease the ABCG2 activity in mammalian cells. However, the precise mechanism remains unclear. To better understand the role of cholesterol in the ABCG2 activity, we studied the ABCG2-mediated efflux of different substrates in the presence of different concentrations of cholesterol. Moreover, we synthetized derivatives of cholesterol linked either to known ABCG2 inhibitors or fluorescents probes. A chalcone-cholesterol was synthetized to investigate the influence of cholesterol on ABCG2 inhibition, and a BODIPY-cholesterol was developed to track cholesterol trafficking on mammalian cells and investigate the behavior of cholesterol as an ABCG2 substrate. The obtained results with three different substrates of ABCG2 showed that cholesterol did not affect the intracellular amount of substrates nor the transport activity.

Low cure rate and high death rate of cancers have seriously threatened human health. The combining multiple therapies is a promising strategy for cancer treatment. In this study, we construct a novel multinucleated nanocomplex loaded with carbon dots (CDs-SA@TAMn) that responds to tumor microenvironment for combined photothermal/chemodynamic cancer therapy. Fluorescence imaging results show that CDs-SA@TAMn can effectively accumulated in tumor sites. In acidic tumor microenvironment, CDs-SA@TAMn will release Mn2+, activating chemodynamic therapy and producing substantial reactive oxygen species (ROS) to kill tumor. Additionally, when irradiated by an 808 nm laser, CDs-SA@TAMn will exert the photothermal effect to realize high performance of cancer hyperthermia treatment. The nanocomplexes feather simple preparation, low toxicity, controlled release and imaging-guided therapy, showcasing the potential of precise and high performance anti-tumor combination therapy in biomedical applications.

Macrocyclic supramolecular materials play an important role in encapsulating anticancer drugs to improve the anticancer efficiency and reduce the toxicity to normal tissues through host-guest interactions. Among them, pillar[n]arenes, as an emerging class of supramolecular macrocyclic compounds, have attracted increasing attention in drug delivery and drug-controlled release due to their high biocompatibility, excellent host-guest chemistry, and simplicity of modification. In this review, we summarize the research progress of pillar[n]arene-based supramolecular nanodrug delivery systems (SNDs) in recent years in the field of tumor therapy, including drug-controlled release, imaging diagnostics and therapeutic modalities. Furthermore, the opportunities and major limitations of pillar[n]arene-based SNDs for tumor therapy are discussed.

The antiausterity strategy in anticancer drug discovery has attracted much attention as a way to exterminate cancer cells under nutrient deprived conditions which are commonly found in solid tumors. These tumors under low nutrient stress are known to be malignant and often resist conventional drug therapy. As a potential drug candidate, we focused on the meroterpenoid natural product callistrilone O which has demonstrated extremely potent antiausterity properties toward PANC-1 pancreatic carcinoma in vitro. Here, we report for the first time the total synthesis of callistrilone O in seven steps from phloroglucinol. A Friedel-Crafts-type Michael addition and an oxidative [3 + 2] cycloaddition with Fetizon's reagent were used to construct the molecular skeleton. The preferential cytotoxicity of callistrilone O was also evaluated with multiple starvation-resistant cancer cell lines under low nutrient conditions. Furthermore, callistrilone O was found to strongly suppress B16 melanoma tumor growth without critical toxicity in vivo. Overall, this study presents a novel anticancer agent candidate from natural products with a concise synthetic route which can be readily applied to the synthesis of derivatives.

A diversity-oriented collection of furan-2-carboxamides with antibiofilm activity against P. aeruginosa is reported. The design involved the bioisosteric replacement of the labile furanone ring by a furan-2-carboxamide moiety to explore its influence on biological activity. After evaluation, carbohydrazides and triazoles showed significant antibiofilm activity, and 4b resulted in the most remarkable compound (58% inhibition). Furthermore, treating P. aeruginosa with three active compounds reduced some virulence factors (pyocyanin and proteases), confirming the anti-quorum sensing properties of the derivatives and suggesting LasR as a plausible target. Molecular docking proposed that carbohydrazides share a similar binding mode to related furanones inside LasR with an excellent docking score, while higher derivatives diminished in silico affinity.

Tumor-associated human carbonic anhydrases (hCAs), particularly isoforms hCA IX and hCA XII, are overexpressed in hypoxic regions of solid tumors and play a crucial role in regulating pH homeostasis, promoting cancer cell survival and enhancing invasiveness. These enzymes have emerged as promising therapeutic targets in cancer treatment, including photothermal therapy (PTT). PTT is a minimally invasive technique that uses light-absorbing agents to convert near-infrared (NIR) light into heat, effectively inducing localized hyperthermia and promoting cancer cell apoptosis. Recent advances in the design of hCA-targeted photothermal agents have shown promise in selectively targeting and ablating cancer cells while sparing healthy tissues. We explore here recent advancements in developing combination therapies that integrate hCA-targeted strategies with PTT for tumor treatment. By focusing on tumor-associated isoforms hCA IX and hCA XII, we underscore the potential of hCA inhibition to enhance both the efficacy and specificity of PTT in cancer therapy. We also address critical challenges and outline future directions, emphasizing the need to improve the biocompatibility, stability, and clinical translation of hCA-targeted photothermal agents. This mini review highlights the promise of combining hCA inhibition with PTT as an innovative therapeutic approach, aiming to advance more precise and effective cancer treatments.

Optimizing pharmacokinetics is an integral part of drug design, albeit a lesser understood one from the medicinal chemist's perspective. Over the years, molecular tools and experimental strategies have been developed to better understand the fate of compounds. Among these, the use of aminobenzotriazole (ABT), elacridar and bile-duct cannulated rats have been instrumental in gaining valuable PK insights, with a direct impact on drug design.