Maleimide Derivatives Research Articles

Development of a Novel Label-Free Subunit HILIC-MS Method for Domain-Specific Free Thiol Identification and Quantitation in Therapeutic Monoclonal Antibodies.

Cysteine residues are crucial for the formation of conserved disulfide bonds in therapeutic monoclonal antibodies (mAbs), which are essential for their folding and structural stability. The presence of free thiols in mAbs can indicate incomplete disulfide bond formation, potentially impacting the molecule's conformational stability. Free thiol quantitation has been achieved using labeling-based strategies such as maleimide and haloalkyl derivatives at both intact and peptide levels. However, intact-level measurement only provides total free thiol levels, while peptide-level measurement is time-consuming and more prone to assay-induced artifacts. In this study, we present a novel label-free HILIC-MS method that separates free thiol species at the subunit level, followed by free thiol localization by the MS2 fragmentation pattern. This allows for facile identification and quantitation of intrachain free thiols at domain-specific resolution. Compared to bottom-up approaches, this subunit HILIC-MS method excels in simpler sample preparation and higher throughput and enables chain-specific free thiol analysis for bispecific mAbs. This method can be readily applied for screening mAb candidates with elevated levels of free thiols in early-stage developability assessment and facilitating an effective comparability evaluation of mAb samples during process development.

Evaluation of Potency and Specificity of Cryptophycin-Loaded Antibody-Drug Conjugates.

An enhanced variant of the antimitotic toxin cryptophycin was conjugated to the anti-Her2 monoclonal antibody (mAb) Trastuzumab upon Michael addition. Either antibodies with freed hinge-region cysteines or THIOMAB formats with engineered cysteines in the mAbs light chain were added to a maleimide derivative of cryptophycin. These Antibody-Drug Conjugates (ADCs) showed retained binding to Her2 positive tumor cells and highly efficient cell killing in double-digit pM range on high Her2-expressing SK-BR-3 cells. Two ADCs (DAR6, DAR3) showed superior cell killing of the cell lines JIMT-1 and RT112 with medium receptor expression level in comparison with a DAR6 MMAE ADC serving as reference. The observed cell cytotoxicity is target-dependent since no impact on cell viability was observed for low Her2-expressing MDA-MB468 cells. Particularly the DAR3 ADC in THIOMAB format exhibiting desirable biophysical properties and high potency emerged as a promising candidate for further in vivo investigations.

Design, Synthesis, Biological Evaluation and Molecular Docking Studies of a New Series of Maleimide Derivatives.

A series of novel maleimide derivatives were synthesized, with various heterocyclic compounds serving as side chains in the synthesis process. The structural characteristics of these compounds were elucidated through the application of 1H-NMR spectroscopy, 13C-NMR (APT) spectroscopy, and high-resolution mass spectrometry (HRMS). The anti-cancer potential of these compounds was subsequently assessed in vitro, utilizing two distinct breast cancer cell lines, namely MDA-MB-231 and MCF-7, via MTT assay. Among the 12 newly synthesized compounds, 4 a, 4 b, 4 c, 4 d, 5 a, 5 b, 5 c and 5 d were determined to show the most promising anti-cancer activity against both breast cancer cell lines. Moreover, the morphological changes induced in the cells following a 24-hour incubation period with these compounds were observed using light microscopy. Additionally, molecular dynamics simulations were conducted to assess the stability of the bound conformations of the compounds to the target protein GSK-3β as obtained through molecular docking calculations.

Single-molecule sensing inside stereo- and regio-defined hetero-nanopores.

Heteromeric pore-forming proteins often contain recognition patterns or stereospecific selection filters. However, the construction of heteromeric pore-forming proteins for single-molecule sensing is challenging due to the uncontrollability of producing position isomers and difficulties in purification of regio-defined products. To overcome these preparation obstacles, we present an in situ strategy involving single-molecule chemical modification of a heptameric pore-forming protein to build a stereo- and regio-specific heteromeric nanopore (hetero-nanopore) with a subunit stoichiometric ratio of 3:4. The steric hindrance inherent in the homo-nanopore of K238C aerolysin directs the stereo- and regio-selective modification of maleimide derivatives. Our method utilizes real-time ionic current recording to facilitate controlled voltage manipulation for stoichiometric modification and position-based side-isomer removal. Single-molecule experiments and all-atom molecular dynamics simulations revealed that the hetero-nanopore features an asymmetric stereo- and regio-defined residue structure. The hetero-nanopore produced was characterized by mass spectrometry and single-particle cryogenic electron microscopy. In a proof-of-concept single-molecule sensing experiment, the hetero-nanopore exhibited 95% accuracy for label-free discrimination of four peptide stereoisomers with single-amino-acid structural and chiral differences in the mixtures. The customized hetero-nanopores could advance single-molecule sensing.

Synthesis of 3,4-Disubstituted Maleimide Derivatives via Phosphine-Catalyzed Isomerization of α-Succinimide-Substituted Allenoates Cascade γ'-Addition with Aryl Imines.

3,4-disubstituted maleimides find wide applications in various pharmacologically active compounds. This study presents a highly effective approach for synthesizing derivatives of 3,4-disubstituted maleimides through the direct isomerization of α-succinimide-substituted allenoates, followed by a cascade γ'-addition and aryl imines using PR3 as a catalyst. The resulting series of 3,4-disubstituted maleimides exhibited excellent stereoselectivities, achieving yields of up to 86%. To our knowledge, the phosphine-mediated γ'-addition reaction of allenoates is seldom reported.

A DFT Study of Mechanism, Diastereoselectivity, and Solvent Effects on the 1,3-Dipolar Cycloaddition Reaction between N-Methyltrichloromethylnitrone and Maleimide Derivatives

A DFT Study of Mechanism, Diastereoselectivity, and Solvent Effects on the 1,3-Dipolar Cycloaddition Reaction between N-Methyltrichloromethylnitrone and Maleimide Derivatives

Synthesis, Biological Screening, and Molecular Dockingof Drug Carrier Maleimide Derivatives

Synthesis, Biological Screening, and Molecular Dockingof Drug Carrier Maleimide Derivatives

High-Impact Epoxy Resins with Superior Hydrophobicity Toughened by Epoxy Functionalized Poly(olefin-alt-maleimide) Derivatives

High-Impact Epoxy Resins with Superior Hydrophobicity Toughened by Epoxy Functionalized Poly(olefin-<i>alt</i>-maleimide) Derivatives

Low‐Cost, Large‐Area, and Highly Transparent Organic Glassy Scintillators for High Resolution X‐Ray Imaging

AbstractThe architectural design and fabrication of low‐cost, high‐performance organic scintillators are critical for medical imaging and material/device analysis. However, achieving large‐area and high‐transparency organic scintillators in a low‐cost and easy‐to‐implement method remains a challenge. Herein, a new design strategy for regulating the side chain length of maleimide derivatives is demonstrated to develop organic scintillators for achieving low‐cost, large‐area, and high spatial resolution in X‐ray imaging. The effective intermolecular interactions and relatively twisted molecular structure endow PAM‐M4 molecule with outstanding scintillator properties. More importantly, as demonstrated for the first time, pure organic glassy films with a diameter over 10 cm and high optical transparency can be prepared by the developed melt‐quenched method using PAM‐M4 crystal powder as a raw material. This glassy film exhibits excellent X‐ray imaging ability with a spatial resolution as high as 27.0 lp mm−1 at MTF = 0.20, which is one of the best results among reported organic scintillators. The results of this work not only develop a new design strategy for high‐performance organic scintillators but also demonstrate a reliable approach to fabricating large area screens with superior spatial resolution for medical or industrial X‐ray imaging applications.

A Golgi Apparatus-Targeted Photothermal Agent with Protein Anchoring for Enhanced Cancer Photothermal Therapy.

The Golgi apparatus (GA) is central in shuttling proteins from the endoplasmic reticulum to different cellular areas. Therefore, targeting the GA to precisely destroy its proteins through local heat could induce apoptosis, offering a potential avenue for effective cancer therapy. Herein, a GA-targeted photothermal agent based on protein anchoring is introduced for enhanced photothermal therapy of tumor through the modification of near-infrared molecular dye with maleimide derivative and benzene sulfonamide. The photothermal agent can actively target the GA and covalently anchor to its sulfhydryl proteins, thereby increasing its retention within the GA. Under laser irradiation, the heat generated by the photothermal agent efficiently disrupts sulfhydryl proteins in situ, leading to GA dysfunction and ultimately inducing cell apoptosis. In vivo experiments demonstrate that the photothermal agent can precisely treat tumors and significantly reduce side effects.

Antifungal activity of a maleimide derivative: disruption of cell membranes and interference with iron ion homoeostasis

ABSTRACT Fungal infections caused by Candida albicans have posed a persistent threat to human health. Existing clinical antifungal drugs are constrained by issues such as drug resistance and side effects. Compounds containing maleimide rings have been verified to possess antifungal properties, although the specific molecular mechanisms by which they exert this activity have yet to be fully understood. A total of 40 compounds containing maleimide rings were synthesised in the present study, and 12 derivatives that possessed antifungal properties were subsequently identified. The maleimide compound 5 (MPD) with the most potent activity demonstrated fungicidal action at a concentration that was twice as potent as the minimal inhibitory concentration and effectively prevented the formation of biofilms. Furthermore, the mechanistic studies revealed that MPD interfered with iron ion homoeostasis by reducing intracellular iron concentration inside cells, which led to the inhibition of ergosterol biosynthesis and increased cell membrane permeability, resulting in the leakage of intracellular trehalose. In addition, MPD was observed to perturb cell wall biosynthesis by reducing the activity of chitin synthase. Moreover, MPD was found to demonstrate therapeutical efficacy in vivo when assessed using a Caenorhabditis elegans-C. albicans infection model.

Variable swelling behavior of and drug encapsulation in a maleimide-modified hyaluronic acid nanogel-based hydrogel

Hyaluronic acid (HA) has garnered much attention in the development of novel hydrogels. Hydrogels, as drug delivery systems, are very important in tissue engineering applications. In this study, we developed a novel HA nanogel containing a cholesterol and maleimide derivative (HAMICH) and its corresponding crosslinked hydrogel (HAMICH gel) to encapsulate drugs for their subsequent release. HAMICH gels self-assemble into nanoparticles via hydrophobic interactions. Dynamic light scattering analysis of HAMICH revealed that the particle size tended to decrease with increasing degree of cholesterol moiety substitution. The HAMICH gel was prepared through a Michael addition reaction between HAMICH and pentaerythritol tetra(mercaptoethyl)polyoxyethylene. The concentration of HAMICH needed for gelation depends on the degree of cholesterol moiety substitution; the higher the substitution degree is, the greater the concentration of HAMICH needed. The HAMICH gel exhibited less swelling and a smaller volume change than the gel with an unmodified cholesterol moiety in phosphate-buffered saline (pH 7.4). The HAMICH gel displayed enhanced peptide and protein trapping abilities without hydrogel swelling, suggesting its potential as a HA hydrogel for biomedical applications.

Visible Light‐Promoted Catalyst‐Free (VLCF) Scalable Synthesis of Novel Derivatives of Isoniazid and Maleimide

AbstractWe have developed a Visible Light Promoted Catalyst‐Free (VLCF) approach to synthesize novel conjugates of Isoniazid and Maleimide. This method involves the formation of an electron donor‐acceptor (EDA) complex between isoniazid and maleimide the photochemical activity of this complex drives the transformation. We successfully synthesized Isoniazid‐Maleimide derivatives (3a–d) at gram scale under visible light irradiation without an additional photo catalyst and without chromatographic purification resulting in excellent yields in a recyclable green solvent. Molecular docking was employed to predict the in silico anti‐tubercular activity and binding modes at the active site of enoyl‐ACP reductase, InhA. The newly synthesized compounds (3a–d) exhibited high binding affinity compared to Isoniazid and Isoniazid‐NAD adduct, indicating their potential for more effective anti‐tubercular activity. ADME analysis revealed favourable physicochemical properties, lipophilicity, water solubility, pharmacokinetics, and drug‐likeness for compound 3a, positioning it as a promising candidate for further drug discovery and development.

Integrated computational and experimental design of fluorescent heteroatom-functionalised maleimide derivatives.

The bottom-up design and synthesis of organic molecular species with tailored photophysical properties stands as an important challenge to both computational and experimental chemical science. Overcoming this challenge presents the potential to usher in new tools and approaches to improve our ability to develop new technologies, such as molecular sensors and attuned molecular switches. Here, we report the bottom-up design and characterisation of new fluorescent maleimide derivatives using coupled computational and experimental insights. Using an extensive set of experimentally-measured UV/visible spectra for different functionalized maleimides in different solvents, we train an artificial neural network (ANN) to rapidly correlate maleimide structure (and solvent) with emission spectra characteristics. We subsequently use this computational predictor to identify design principles for novel functionalised maleimide structures with targeted photophysical properties; synthesis and characterisation of several new maleimides demonstrates how this combined strategy can offer new directions for tuning photochemistry, for example opening new routes to designing tailor-made fluorescent probes.

Development of potent and effective SARS-CoV-2 main protease inhibitors based on maleimide analogs for the potential treatment of COVID-19

In the present work, we report a new series of potent SARS-CoV-2 Main Protease (Mpro) inhibitors based on maleimide derivatives. The inhibitory activities were tested in an enzymatic assay using recombinant Mpro (3CL Protease from coronavirus SARS-CoV-2). Within the set of new Mpro inhibitors, 6e demonstrated the highest activity in the enzymatic assay with an IC50 value of 8.52 ± 0.44 µM. The IC50 value for Nirmatrelvir (PF-07321332, used as a reference) was 0.84 ± 0.37 µM. The cytotoxic properties were determined in the MTT assay using MRC-5 and HEK-293 cell lines. In the course of the investigation, we found that the newly obtained maleimide derivatives are not substantially cytotoxic (IC50 values for most compounds were above 200 µM).

Blue Light‐Promoted Synthesis of Thiochromenopyrroledione Derivatives via Titanium Dioxide‐Catalyzed Dual Carbon–Carbon Bond Formation with Thioanisole and Maleimide Derivatives

AbstractUnder anaerobic conditions, thioanisole derivatives bearing a thiomethyl group participated in dual carbon‐carbon bond‐forming reactions with maleimide derivatives in the presence of titanium dioxide. Blue light irradiation facilitated these reactions, producing thiochromenopyrroledione derivatives and nearly equimolar quantities of succinimide derivatives. Specifically, a thiochromenopyrroledione derivative formed from thioanisole and N‐benzylmaleimide was achieved with a 43% yield after 12 hours of blue light exposure (&gt;420 nm), approaching its theoretical maximum yield of 50%. Without titanium dioxide, the reaction remained dormant. Our investigations with five varieties of 4‐substituted thioanisoles and four N‐substituted maleimides as precursors resulted in the synthesis of 20 distinct thiochromenopyrroledione derivatives with moderate to high yields. From observed substituent effects, we postulate that this reaction proceeds through a charge transfer from thioanisole to the conduction band of titanium dioxide during blue light irradiation, initiating the one‐electron oxidation of thioanisole and subsequent generation of α‐thioalkyl radicals via deprotonation.

Palladium-Catalyzed Tandem Cyclization of Bromoalkynes, Anilines and CO: Access to 1,3-Substituted Maleimides.

A novel palladium-catalyzed three-component carbonylation reaction for the assembly of various 1,3-substituted maleimide derivatives from haloalkynes and simple anilines. The nucleophilic addition reaction of haloalkynes, anilines and CO, and insertion of carbonyl have been achieved sequentially in this reaction. The high chemo- and regioselectivities, as well as no need of expensive ligands or additives further illustrate the synthetic value of this approach.

Synthesis, characterization of a new series of thiohydantoin derivatives and study their biological activity against prostate cancer and microbes.

Prostate cancer is one of the most common malignant diseases in men, and the design of new chemical compounds against prostate cancer is one of the challenges faced by modern medicine. In this study, we prepared and characterized a new series of thiohydantoin derivatives by reacting maleimide derivatives (1C-4) with cyclohexyl isothiocyanate.The prepared compounds were diagnosed using (FT-IR ,1H-NMR ,13C-NMR ).MTT assay was used to determine the activity of the prepared compounds against prostate cancer cell lines, as the data indicated, based on IC50 values, that the prepared compounds do not have anti-prostate cancer activity. The prepared compounds were also studied against selected types of bacteria and fungi, as the data indicated that some of the prepared series compounds had anti-bacterial and anti-fungal activity under study, as the compound 4C showed a high anti-staph activity.

Design, Synthesis and Antifungal Evaluation of N-Substituted Maleimide Derivatives with Imidazole and 2-Methyl Imidazole Moieties

A series of N-substituted maleimide derivatives with an attached imidazole and 2-methyl imidazole heterocyclic rings were designed, synthesized and evaluated for their antifungal activity against four pathogenic fungi. 1H-NMR, 13C-NMR and mass spectra confirmed the chemical structures of all synthesized compounds. All compounds 4a-4g, 5b and 5f were initially screened for qualitative (zone of inhibition) antifungal activity against C. albicans, A. fumigatus, A. niger, and A. oryzae. The screening results indicate that most of the synthesized compounds showed significant antifungal activity against the tested fungi. Furthermore, the compounds that showed a significant zone of inhibition were selected and tested quantitatively (MIC50 and IC50) against the same pathogenic fungi species. The MIC50 and IC50 results of selected compounds were analyzed. These results strongly suggest that compound 5f has shown promising antifungal activity. Furthermore, the structure–activity relationship of compound 5f revealed that the compound substituted with the –F group possess prominent antifungal activity.

Bisindolyl Maleimides and Indolylmaleimide Derivatives-A Review of Their Synthesis and Bioactivity.

The evolution of bisindolyl maleimides and indolyl maleimide derivatives and their unique biological activities have stimulated great interest in medicinal chemistry programs. Bisindolylmaleimide (BIM)-type compounds arise from natural sources such as arcyriarubin and are biosynthetically related to indolocarbazoles. BIMs are commonly the immediate synthetic precursors of indolocarbazoles, lacking a central bond between the two aromatic units and making them more flexible and drug-like. Synthetic endeavours within this class of compounds are broad and have led to the development of both remarkably potent and selective protein kinase inhibitors. Clinical BIM examples include ruboxistaurin and enzastaurin, which are highly active inhibitors of protein kinase C-β. While BIMs are widely recognised as protein kinase inhibitors, other modes of activity have been reported, including the inhibition of calcium signalling and antimicrobial activity. Critically, structural differences can be used to exploit new bioactivity and therefore it is imperative to discover new chemical entities to address new targets. BIMs can be highly functionalised or chemically manipulated, which provides the opportunity to generate new derivatives with unique biological profiles. This review will collate new synthetic approaches to BIM-type compounds and their associated bioactivities with a focus on clinical applications.