Search Results (762)

Dravet syndrome (DS) and Lennox–Gastaut syndrome (LGS) are rare, severe developmental and epileptic encephalopathies with poor prognosis, and novel drugs are urgently needed to meet clinical needs. CYP46A1 (cholesterol 24-hydroxylase, CH24H) is mainly responsible for the metabolism of cholesterol to 24(S)-hydroxycholesterol in the brain and is implicated in many brain disorders through the mediation of excitatory amino acid transporter 2 (EAAT2) and N-methyl-D-aspartate (NMDA) receptors. Inhibition of CYP46A1 is supposed to provide a novel treatment for disorders associated with neural hyperexcitation, such as epilepsy and epileptic syndromes. Soticlestat, a potent CYP46A1 inhibitor being developed by Takeda, is indicated for LGS and DS but suffers from unsatisfactory in vivo potency in animal models and clinical trials. We designed three series of soticlestat derivatives to explore the structure–activity relationship (SAR) with the aim of finding more potent CYP46A1 inhibitors and understanding the SAR of CYP46A1 inhibitors represented by soticlestat. Eventually, three compounds with a benzenesulfonamide moiety (in subseries C-4) that serves as an isostere of OH in soticlestat were discovered with very potent CYP46A1 inhibitory activities comparable to soticlestat, and an interesting flat SAR profile was observed in some subseries. The findings in the present study provide insight into the SAR of CYP46A1 inhibitors and should be valuable for the future design of novel CYP46A1 inhibitors. Full article

Non-small-cell lung cancer (NSCLC) is one of the most prevalent cancer types and accounts for the majority of cancer-related deaths worldwide. Tanshinone and its derivatives exhibit diverse biological activities, and their prominent antitumor potential has been well documented. In this study, we rationally designed a series of tanshinone derivatives with a scaffold-hopping strategy. Thirty-five tanshinone derivatives were synthesized, and their cytotoxic activities against the NSCLC cell lines A549 and H838 were investigated. Concurrently, their safety profile was assessed in BEAS-2B cells. The results showed that compounds S2-1, S2-4, and S2-8 exhibited superior inhibitory activity against A549 cells compared with the positive control, β-lapachone. Meanwhile, compounds S2-1, S2-3, S2-4, S2-8, S2-13, and S2-14 exhibited similar or increased antiproliferation activity against H838 cells. Compounds S2-4 (0.58 ± 0.07 μM) and S2-8 (0.42 ± 0.04 μM) demonstrated the greatest potency towards H838 cells; compounds S2-13 (1.28 ± 0.13 μM) and S2-14 (1.80 ± 0.24 μM) exhibited potent and selective activity towards H838 cells. Molecular docking studies of S2-4/NLRP3 and S2-14/STAT3, combined with the structure–activity relationship (SAR) analysis, indicated that the benzofuran core containing an ortho-quinone, along with an amide linkage and a 1,2,3-triazole group introduced at the C-2 position of the furan ring, is an effective chemical scaffold for enhancing the anti-NSCLC activity of tanshinone derivatives. Full article

Dihydroartemisinin (DHA), a first-line treatment for uncomplicated malaria, has demonstrated antitumor activity against a variety of human cancers, emphasizing its potential for repurposing as an anticancer agent. However, its short half-life and poor bioavailability hinder its application in cancer therapy. We previously demonstrated that the molecular hybridization of DHA with bile acids (BAs) enhances its anticancer activity by improving stability and reducing toxicity. Based on this rationale, here, we designed and synthesized a library of DHA-based hybrids through conjugation with ursodeoxycholic and chenodeoxycholic bile acids. Different conjugation sites and both cleavable and non-cleavable linkages were explored to enable a comprehensive structure–activity relationship analysis. The resulting BA-DHA hybrids were evaluated in vitro for their anticancer activity against HCT116 and RKO colorectal cancer cell lines. As a result of the synergistic effect of the linker type and conjugation site, the BA-DHA hybrids synthesized via click chemistry emerged as the most active compounds in both cell lines, displaying 2- to 20-fold higher activity than the parent DHA. Mechanistic investigations further revealed that the click-derived BA-DHA hybrids possess enhanced anticancer activity and antimetastatic potential, achieving comparable or even superior efficacy to the parent compound at markedly lower concentrations. Full article

The indole scaffold represents a privileged structural motif in medicinal chemistry, celebrated for its remarkable chemical versatility, biological ubiquity, and clinical relevance. This review provides a comprehensive analysis of the recent research on the indole nucleus, emphasizing its physicochemical properties, reactivity patterns, and capacity to interact with a wide array of biological targets. Found in key endogenous compounds such as serotonin and melatonin, indole serves as a cornerstone in neurochemical signaling, circadian regulation, and chrono-metabolic homeostasis. Beyond its physiological roles, synthetic indole derivatives have shown extensive therapeutic potential across diverse domains, including oncology, infectious diseases, neurodegenerative disorders, immunomodulation, and metabolic syndromes. The review explores structure–activity relationships (SAR), pharmacokinetics, and the molecular mechanisms by which indole-based compounds exert their tremendous effects, that are ranging from enzyme inhibition to receptor modulation. Special focus is given to current clinical applications and emerging strategies for enhancing drug specificity, bioavailability, and safety through indolic frameworks. Additionally, we highlight the translational potential of indole-containing molecules in personalized medicine, underscoring opportunities for future drug discovery. By integrating insights from medicinal chemistry, biochemistry, pharmacology, and clinical science, this review affirms the indole ring’s enduring value as a central scaffold in therapeutic innovation. Full article

Background: Heterocyclic compounds are particularly important in medicinal chemistry. With a range of therapeutic uses, benzimidazoles and quinolines are both key heterocycles in medicinal chemistry. A number of hybrid heterocyclic compounds have been reported in recent years because they typically have better therapeutic properties than single heterocyclic rings. Methods: A literature search was conducted across relevant scientific literature from peer-reviewed sources, using keywords, including “benzimidazole”, “quinoline”, “benzimidazole-quinoline hybrids”, “antibacterial”, “antifungal”, “antimalarial” and “hybrid complexes”. Results: This review summarizes the synthetic methodologies for benzimidazole–quinoline hybrids, benzimidazole– quinolinones, and benzimidazole–quinoline metal complexes, along with their antimicrobial and antimalarial activities and the reported structure–activity relationship (SAR) studies. The importance of halogen substitution, particularly with chlorine and fluorine atoms, as well as the structure of the linker between the benzimidazole and quinoline rings—specifically chain length, the presence of oxygen, sulfur, or nitrogen atoms, and heterocyclic moieties—is highlighted. A series of benzimidazole–quinoline hybrids exhibit antimalarial and antitrypanosomal activities or show enhanced antimicrobial properties due to the incorporation of a five-membered heterocycle in addition to the two existing heterocyclic rings. Notably, several hybrids from different compound series exhibit very low minimum inhibitory concentrations (MICs) in the range of 1–8 µg/mL, along with low cytotoxicity, supporting their potential for further investigation as antimicrobial agents. Conclusions: This review summarizes the synthetic methods, medicinal properties, and structure–activity relationship (SAR) studies of benzimidazole–quinoline hybrids reported between 2002 and 2026. Full article

Pine wilt disease (PWD), caused by Bursaphelenchus xylophilus, is driven by a tri-component system involving the pinewood nematode, Monochamus spp. beetle vectors, and susceptible pine hosts. Chemical control remains a scenario-dependent option for emergency suppression and high-value protection, but its deployment is constrained by strong regional regulatory and practical differences. In Europe (e.g., Portugal and Spain), field chemical control is generally not practiced; post-harvest phytosanitary treatments for wood and wood packaging rely mainly on heat treatment, and among ISPMs only sulfuryl fluoride is listed for wood treatment with limited use. This review focuses on recent progress in PWD chemical control, summarizing advances in nematicide discovery and modes of action, greener formulations and delivery technologies, and evidence-based, scenario-oriented applications (standing-tree protection, vector suppression, and infested-wood/inoculum management). Recent studies highlight accelerated development of target-oriented nematicides acting on key pathways such as neural transmission and mitochondrial energy metabolism, with structure–activity relationship (SAR) efforts enabling lead optimization. Formulation innovations (water-based and low-solvent products, microemulsions and suspensions) improve stability and operational safety, while controlled-release delivery systems (e.g., micro/nanocapsules) enhance penetration and persistence. Application technologies such as trunk injection, aerial/Unmanned aerial vehicle (UAV) operations, and fumigation/treatment approaches further strengthen scenario compatibility and operational efficiency. Future research should prioritize robust target–mechanism evidence, resistance risk management and rotation strategies, greener formulations with smart delivery, and scenario-based exposure and compliance evaluation to support precise, green, and sustainable integrated control together with biological and other sustainable approaches. Full article

Lipopeptides (LPs) have evolved from naturally occurring compounds to key therapeutic agents against multidrug-resistant (MDR) bacterial infections. However, their expanding clinical use has triggered emerging resistance mechanisms, posing serious challenges to anti-infective therapy. This systematic review outlines the development of LP resistance and highlights innovative strategies to counteract it. To overcome these evolving barriers, the field has transitioned from traditional empirical optimization to multidimensional rational design. Moving beyond conventional structure–activity relationship (SAR)-guided chemical synthesis, current approaches integrate diverse innovative methodologies. Based on these advances, this review provides the first systematic summary of contemporary strategies for developing novel LPs, offering new perspectives and methodological support to combat resistant bacterial infections and accelerate the development of next-generation LP-based therapeutics. Full article

The arachidonic acid pathway plays a pivotal role in the biosynthesis of important inflammatory and signal transducing agents such as prostaglandins, leukotrienes and thromboxanes. When this pathway is deregulated, it leads to pathological conditions such as cardiovascular diseases, metabolic diseases, and cancer. Two key enzymes of the pathway are cyclooxygenases (COXs) and lipoxygenases (LOXs), which are responsible for the production of prostaglandins and leukotrienes, respectively. Consequently, these enzymes have long been recognized as key therapeutic targets for the treatment and management of inflammatory disorders and other pathological conditions associated with inflammation. In this review, we describe the new evidence over the last 4 years regarding the arachidonic acid pathway. Moreover, we will pay attention to the structure and function of the COX-2 and 5-LOX enzymes and their role in inflammation, as well as define their active sites. Later, we will discuss the most potent, dual inhibitors of COX-2 and 5-LOX enzymes, based on in vitro and in vivo experiments, from 2020–2024. Structure–activity relationship (SAR) analysis of these compounds revealed four key structural features required for potent dual inhibition of cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX). We refer to these criteria as “The Rule of Four for Inflammation”. Full article

The continuous emergence of SARS-CoV-2 variants, especially the Omicron strain with its heightened transmissibility, has posed ongoing challenges to the efficacy of existing vaccine and drug regimens. This situation highlights the pressing demand for antiviral drugs employing novel mechanisms of action. Pentacyclic triterpenoids (PTs), a structurally varied group of compounds derived from plants, exhibit both antiviral and anti-inflammatory activities, making them attractive candidates for further therapeutic development. These natural products, along with their saponin derivatives, show broad-spectrum inhibitory effects against multiple SARS-CoV-2 variants (from Alpha to Omicron) via interactions with multiple targets, such as the spike protein, main protease (Mpro), RNA-dependent RNA polymerase (RdRp), and inflammatory signaling pathways. This review consolidates recent findings on PTs and their saponins, emphasizing their influence on the key structural features required for inhibiting viral attachment, membrane fusion, reverse transcription, and protease function. We systematically summarized the structure–activity relationships and their antiviral results of PTs based on different target proteins in existing studies. Furthermore, this work points toward new strategies for designing multi-target PT-based inhibitors with improved efficacy against Omicron and future variants. Full article

Alzheimer’s disease (AD) remains an unmet medical challenge, as there are no effective therapies that alter the disease’s progression. While approaches have targeted molecules like acetylcholine (ACh) and glutamate, these strategies have provided only limited benefits and do not address the complex molecular mechanisms underlying AD development. This review suggests that β-alanine (3-aminopropanoic acid) is an underexplored neurotransmitter that could serve as a potential AD drug target. Existing evidence indicates that β-alanine modulates GABAergic and glutamatergic neurotransmission, thereby affecting neuronal hyperexcitability. Additionally, studies suggest that β-alanine has antioxidant effects, reducing oxidative stress caused by reactive oxygen species (ROS). We propose that β-alanine might bind to Aβ/tau proteins, possibly targeting the six-amino acid sequences EVHHQK/DDKKAK, which are involved in protein aggregation. β-Alanine may also influence the release of pro-inflammatory cytokines from microglia, potentially reducing neuroinflammation. We also hypothesize that β-alanine may help regulate metal dyshomeostasis, which leads to ROS production. Taurine, structurally like β-alanine, appears to influence comparable mechanisms. Although structural similarity doesn’t ensure therapeutic effectiveness, this evidence supports considering β-alanine as a treatment for AD. Furthermore, β-alanine and its analogues face challenges, including crossing the blood–brain barrier (BBB) and optimizing structure–activity relationships (SAR). This review includes articles through September 2025, sourced from four databases. Full article

Background: Infections caused by the protozoan Trichomonas vaginalis affect millions of people worldwide and are responsible for one of the most common sexually transmitted diseases. Despite the efficacy of 5-nitroimidazoles like metronidazole, concerns regarding widespread resistance and the absence of viable alternatives for specific patient populations necessitate the development of structurally diverse pharmacological agents. In this study, we investigated the antiparasitic activity of 1,3-thiazolidin-4-one derivatives against T. vaginalis. Methods: Thiazolidines were synthesized via multicomponent reaction (MCR) using one-pot methodology and tested in vitro against the parasite and mammalian cell lines. Results: Seventy percent of the compounds showed more than 80% antiparasitic activity at 100 μM, with compounds 4a, 4b, and 4f exhibiting IC₅₀ ≤ 20 µM. None of the molecules exhibited cytotoxic against Vero CCL-81 and HeLa cells. Evaluation of the structure–activity relationship (SAR) indicates that the substituent at the nitrogen position of the heterocycle may be involved in the antiparasitic effect of these compounds. In silico studies also revealed that the three compounds possess adequate oral bioavailability and do not present mutagenic, tumorigenic or irritating risks. Finally, molecular docking predicted strong interactions of compounds 4a, 4b, and 4f with T. vaginalis enzymes lactate dehydrogenase and purine nucleoside phosphorylase; compound 4f also interacted with methionine Ƴ-lyase. Conclusions: These preliminary results suggest that 1,3-thiazolidin-4-ones are promising scaffolds for developing new trichomonacidal agents. Full article

Endoperoxides constitute a distinctive class of highly oxygenated terpenoids defined by the presence of a cyclic peroxide (–O–O–) bond, a structural motif responsible for their pronounced chemical reactivity and diverse biological effects. Naturally occurring endoperoxide-containing terpenoids are broadly distributed across terrestrial and marine taxa, including higher plants, algae, fungi, and bryophytes, where they are believed to participate in chemical defense and ecological interactions. This review provides a comprehensive overview of naturally occurring endoperoxide terpenoids, focusing on their natural sources, structural diversity, and reported biological activities. Particular emphasis is placed on compounds exhibiting antiprotozoal and antitumor activities, exemplified by artemisinin and its derivatives, which remain cornerstone agents in antimalarial therapy and continue to attract interest for their anticancer potential. Structure–activity relationship (SAR) analysis, supported by computational prediction using the PASS (Prediction of Activity Spectra for Substances) platform, is employed to examine correlations between peroxide-containing frameworks and biological function. Comparative assessment of experimental data and predicted activity profiles identifies key structural features associated with antiprotozoal, antineoplastic, and anti-inflammatory effects. Collectively, this review highlights endoperoxides as a valuable and chemically distinctive class of bioactive natural products and discusses their promise and limitations as leads for further pharmacological development, particularly in light of their intrinsic reactivity and stability challenges. Full article

Cathinone and its synthetic derivatives are among the most popular classes of narcotics worldwide. Experimental studies have demonstrated variable cytotoxic activity among these substances. Until now, the research on cathinones has been limited to their psychotropic activity. Therefore, the structure–activity correlation in this group remains poorly understood. The current study aimed to expand the understanding of the influence of cathinone structural modifications on cytotoxic activity. A group of cathinones whose cytotoxic activity has been experimentally analyzed by a single research group was studied in silico using density functional theory (DFT). A systematic characterization of the substituent effect and the aromaticity changes depending on the polarity of the medium is presented in this paper. A correlation between growing electron-withdrawing properties of the N-end and its carbonyl fragment as well as aromaticity decrease with growing cytotoxic activity were observed. Full article

Benzoxaboroles have garnered significant interest for their therapeutic potential in various diseases. Among them, 7-propanamide benzoxaborole has served as a new and valuable chemotype for anti-cancer agents, although their definitive intracellular target(s) remains elusive. Herein, three-dimensional quantitative structure–activity relationship (3D-QSAR) was used to systematically investigate the structure–activity relationships (SAR) of a series of 7-propanamide benzoxaboroles. Comparative molecular field analysis (CoMFA, r² = 0.991, q² = 0.626) and comparative molecular similarity indices analysis (CoMSIA, r² = 0.964, q² = 0.605) revealed critical structural determinants of 7-propanamide benzoxaboroles for inhibition of the ovarian cancer cell (SKOV3) proliferation. Based on the guidance of the critical structural determinants, we designed a new benzoxaborole compound 42 with high predicted inhibition activity values. In vitro proliferation assessment showed that compound 42 exhibited superior inhibitory potency to lead compound 1 and comparable activity to compound 41. These findings indicated that the SAR of benzoxaborole compounds through 3D-QSAR can offer valuable theoretical insights for the structural optimization of new benzoxaboroles as anti-SKOV3 agents. Full article

Background: Recently, compounds such as pyrimidine, pyridazine, 1,2,4-triazepine, 1,3,4,6-oxatriazepine, pyridazino[1,2-a]pyrimidine, and pyridazino[1,2-c] pyrimidine, as well as their derivatives, have attracted attention due to their diverse biological activities. Objective: This study focuses on the synthesis of new heterocyclic compounds that feature a seven-membered ring, including pyridazinopyrimido[2,1-c] [1,2,4]triazepine-tetraones (4), pyridazinopyrimidotriazepine-triones (5–8), aminopyri-dazinopyrimido[2,1-c][1,2,4]triazepine-tetraone (9), and 6-amino-8-imino-pyridazino pyrimido[2,1-c] [1,2,4]triazepine-trione (10). These new compounds were synthesized starting from 1-(4-oxo-1,4-dihydropyrimidine)-1,2-dihydropyridazine-3,6-dione (3) and were then evaluated for their antimicrobial activity. Methods: A new series of pyridazino[1,2-a]pyrimido[2,1-c][1,2,4]triazepines and 1,3,4,6-oxatriazepines were synthesized using modern techniques and advanced technology, achieving yields between 72% and 90%. Results: All new compounds were confirmed through IR, ¹H NMR, ¹³C NMR, and mass spectroscopy (MS) and tested for in vitro antimicrobial activity. Compounds (8-10) exhibited excellent antimicrobial activity. Computational analysis provided a comprehensive evaluation of the broad-spectrum inhibitory potential of four lead compounds (6, 8, 9, and 10) against key microbial and fungal targets. These compounds demonstrated consistently superior binding affinities compared to control drugs cefotaxime and nystatin across a range of enzymes essential for pathogen viability and virulence. Conclusions: The structure–activity relationship (SAR) study established a correlation between the tested compounds and their antimicrobial activity. Molecular docking analysis indicated that the in silico results strongly suggest that compounds (6, 8, 9, and 10) are promising multi-target agents capable of disrupting essential bacterial processes and critical fungal pathways, making them excellent candidates for the development of novel antimicrobial therapeutics. These consistent findings support the conclusion that both practical and theoretical studies of the new compounds align with their antimicrobial effectiveness. Full article