Discovery of novel selective HDAC6 inhibitors via a scaffold hopping approach for the treatment of idiopathic pulmonary fibrosis (IPF) in vitro and in vivo

Pulmonary fibrosis (PF), also known as diffuse interstitial pulmonary fibrosis, is a very common end-stage manifestation of several diseases, including idiopathic pulmonary fibrosis (IPF), pulmonary hypertension, and scleroderma, characterised by excessive matrix deposition and destruction of the lung architecture, finally leading to respiratory insufficiency. PF has become a global disease with significantly increased incidence rate, and the most common form of pulmonary fibrosis is idiopathic pulmonary fibrosis (IPF).

Lung fibrosis is a complex disease, a multitude of signal factors and signaling pathways is disrupted in this complex disease, such as TGF-β, Wnt, VEGF and PI3K–Akt. MCE offers a unique collection of 2,653 compounds with identified and potential anti-pulmonary fibrosis activity. MCE Anti-Pulmonary Fibrosis Compound Library is a useful tool for anti-pulmonary fibrosis drugs screening and other related research.

Designed to maximize efficiency in hit discovery and optimization, this compound library is built on a foundation of diverse Bemis-Murcko scaffolds, with each scaffold is represented by two specifically derived molecules. This strategy ensures broad chemical space through scaffold diversity while enabling preliminary functional group exploration. This approach provides early structure-activity relationship (SAR) insights for every scaffold, making it a valuable tool for accelerating drug discovery.

Fibrosis is a kind of repair response to long-term tissue damage, which is mainly manifested by excessive deposition of extracellular matrix (ECM) and scar formation. Myofibroblasts are the main generating cells of extracellular matrix, and their activation process is related to various pathological mechanisms including Oxidative stress, chronic inflammation and cytokine secretion. Fibrosis can occur in many organs, such as kidneys, liver, heart, lungs, etc. Continuous fibrosis can lead to the destruction of the normal structure of tissues and organs, and if not controlled in time, may cause organ failure or even life-threatening.

MCE contains 2,415 compounds targeting ant-fibrosis targets such as TGF-β, PI3K, Wnt, MMP, etc. These compounds have clear or potential anti-fibrosis activity and can be used for mechanism research and drug screening of fibrosis diseases.

At the forefront of innovative drug discovery, every medicinal chemist faces the challenge of rapidly identifying high-quality hit compounds from vast repositories of chemical resources.

The MCE Natural Product Diversity Scaffold Library is the result of a streamlined optimization process built upon our existing natural product collection. Adhering to the rigorous selection principle of "retaining only one representative compound per BMS scaffold", we have concentrated the diversity of thousands of compounds into a high-value, low-redundancy core set containing 2,283 compounds. All compounds are derived from natural sources, inheriting their inherent advantages of structural complexity and drug-likeness. By eliminating redundancy, the library size is significantly reduced without any compromise to chemical diversity. This approach effectively lowers the cost and time required for primary screening while simplifying downstream data analysis and structure-activity relationship (SAR) studies.

ASINEX has elaborated a library of diverse macrocycles using an effective tool box of synthetic methods. The resulting scaffolds are novel, tremendously diverse, medchem-relevant, macrocyclic frameworks.

Macrocyles tend to be larger than traditional screening molecules which make them perfect discovery tools for targets with shallow or extended binding sites. At the same time, their unique character based on restricted flexibility and ability to form intra-molecular hydrogen bonds allows for design approaches effectively optimizing properties such asaqueous solubility and membrane permeability. Many of these macrocycles have been tested for aqueous and DMSO solubility with cut-offs applied at 10 mM in DMSO and 50 µM in PBS (pH 7.4) followed by PAMPA permeability assay.

MCE 5K Scaffold Library consists of 5,000 lead-like compounds. Each compound represents one unique scaffold. All compounds are compatible with Lipinski’s rule (Rule of 5) with multiple characteristics such as calculated good solubility (-3.2 < logP < 5), oral bioavailability (RotB <= 10), drug transportability (PSA < 120). Compounds contained within the library have been screened to remove any inappropriate chemical structures, avoiding “false hits”. The sufficient diverse of compound structure makes this library a powerful tool for drug screening.

The rising prevalence of multidrug-resistant and extensively drug-resistant bacteria, combined with emerging resistance mechanisms and the limitations of existing antibacterial drugs, creates an urgent need for novel antibacterial agents. Antibacterial compound libraries serve as key tools to support antibacterial drug screening and development.

This library features structurally diverse compounds, including small-molecule scaffolds and natural product derivatives, and exhibits diverse antibacterial mechanisms of action. For example, these compounds exert antibacterial effects by disrupting bacterial cell structures, interfering with bacterial metabolic processes, and inhibiting nucleic acid synthesis. The derivation of scaffold structures enhances their activity against drug-resistant bacteria and their selectivity against different types of bacteria. This library can be used for the high-throughput screening of novel antibacterial drug candidates and the identification of potent compounds against drug-resistant and multidrug-resistant bacteria. Additionally, it provides a reference for compound structural modification, enabling further in-depth research on the structure-activity relationships(SARs) of antibacterial drugs. It can also be applied to the exploration of bacterial resistance mechanisms and reversal strategies, as well as the discovery of antibacterial molecules that inhibit efflux pumps and restore drug susceptibility.

The library contains 10855 structurally diverse drug-like compounds. Its core compound sources include analogs of known antifungal active moleculeswith a similarity score of ≥ 0.6. MCE has collected more than 1900 antibacterial molecules. All screened compounds conform to lead-like physicochemical properties, providing valuable support for the research and development of novel antibacterial drugs.

MCE-18 stands for Medicinal Chemistry Evolution 2018, which was first published in Journal of Medicinal Chemistry in 2019 for assessing molecular novelty and three-dimensional complexity. Developed based on Clarivate global pharmaceutical patent database, this descriptor was constructed via big-data analysis covering 28,161 patented lead compounds, 1,370 approved drugs and nearly 30,000 preclinical-to-phase III drug candidates from 23 top pharmaceutical companies worldwide between 1950 and 2018, followed by structural clustering and removal of redundant outdated scaffolds for data denoising. Its scoring system integrates five core structural features including aromatic ring (AR), aliphatic heterocycle (NAR), chiral center (CHIRAL), spiro atom (SPIRO), cyclic and acyclic sp³ carbon ratio together with a quadratic topological correction factor. Breaking the limitations of the single Fsp³ parameter, MCE-18 effectively distinguishes conventional flat aromatic scaffolds from modern 3D-enriched novel chemotypes, overcoming typical drawbacks of traditional compound libraries such as scaffold redundancy, low screening hit rates and poor compatibility with allosteric and PPI-related difficult targets.

This library contains over 37,000 structurally diverse compounds with favorable overall drug-likeness, suitable for high-throughput screening against canonical targets including kinases, GPCRs and proteases as well as challenging allosteric and PPI targets. Compounds comply with the developmental trend of modern novel drug discovery, supporting routine primary screening as well as early hit identification of allosteric modulators and PPI inhibitors, serving as an efficient screening resource for early-stage innovative drug discovery.

According to reports, most known kinase inhibitors exert their effects through competitive binding in highly conserved ATP pockets. Although genetic techniques such as RNA interference can inactivate specific genes, most kinases are multi domain proteins, each of which has an independent function. Highly selective inhibitors have higher efficiency than non-selective inhibitors, and the selectivity to the target is at least 100 times higher. Therefore, ensuring the validation of targets with the most selective inhibitors is crucial for a more thorough understanding of the pharmacology of the kinase field. The Highly Selective Inhibitors Library contains 6,135 compounds, covering multiple targets and subtypes, such as GPCR protein family, Ion channel, multiple kinases, etc. The Highly Selective Inhibitors Library is an effective tool for screening different phenotypes

Agonistic drugs activate or stimulate their receptors, triggering responses that increase or decrease cell activity. The highly selective activators can act on specific biological or molecular targets, while non-selective activators may interfere with multiple targets or targets simultaneously. The highly selective activators reduce the likelihood of these non-specific effects by targeting specific targets, making research more precise and reliable. The Highly Selective Activators Library contains 2,083 compounds, covering multiple targets and subtypes, such as GPCR protein family, Ion channel, multiple kinases, etc. The Highly Selective Activators Library is an effective tool for screening different phenotypes.

“BioDesign” approach incorporates key structural features of known pharmacologically relevant natural products (e.g. alkaloids and other secondary metabolites) into synthetically feasible medicinal chemistry scaffolds. In order to identify the privileged pharmacophores, ring systems and linkers, we have carried out statistical analysis of structural features of natural products, marketed drugs, and drug candidates.

Saturated, fused ring, spiro, and bridged systems with a tendency towards multiple chiral centers are highly privileged among natural products and marketed drugs yet these structures are very poorly represented in commercial libraries. This library addressed this market need by incorporating these privileged elements into the design of novel synthetic molecules with high molecular framework diversity, multiple stereogenic centers (≥2), and degree of saturation (Fsp3 > 0.5).

CRBN, namely cereblon, is the substrate recognition subunit of the E3 ubiquitin ligase complex in the ubiquitin-proteasome system. A CRBN ligand library refers to a collection of numerous fragments that can specifically bind to the CRBN protein.

These ligands are mostly designed based on validated CRBN-binding warheads and modified through AI-driven molecular generation optimization systems. They not only include classic lenalidomide-derived structures but also cover novel non-lenalidomide scaffolds. After drug-likeness filtering, these ligands exhibit structural diversity and favorable druggable properties. They can be further optimized and modified to facilitate the development of novel molecular glue degraders, accelerate the discovery of molecular glues that induce interactions between CRBN and new substrate proteins, and enable the exploration of novel CRBN substrates for identifying previously unknown CRBN-binding proteins.

MCE compiles 125 fragments that can specifically bind to the CRBN protein, with molecular weights ranging from 200 to 500. Compounds developed based on the library ligands target multiple disease targets such as cancer and autoimmune diseases, further advancing the development of Molecular Glues and PROTACs therapeutic agents.

MCE Novel Bioactive Compound Library consists of 2,981 bioactive compounds with validated bioactivities tested by cell-based assays or biochemical assays. All compounds in this library are structurally novel and bioactivity diverse which makes it easier to discover new lead compounds. MCE Novel Bioactive Compound Library, as a supplement of MCE bioactive compound library (HY-L001), is a useful tool to screen new lead compounds.

Macrocycles are promising scaffolds for the design of novel RNA targeting molecules. This collection of macrocycles for RNA consists of very diverse, drug-like molecules which incorporate certain known RNA-recognition elements (e.g. nucleobase ring systems and analogs) distributed within macrocyclic rings or peripheral fragments. As macrocyclic molecules tend to be larger than traditional screening molecules, it is vital to carefully assess and control their physicochemical properties. All macrocycles have been tested for aqueous and DMSO solubility with cutoffs applied at 10 mM in DMSO and 50 µM in PBS (pH 7.4); PAMPA permeability has also been tested for representative set of macrocycles.

Owing to the high conservation of orthosteric sites, conventional orthosteric drugs frequently suffer from poor subtype selectivity, off-target toxicity, and drug resistance, severely restricting their clinical application. In contrast, allosteric sites feature low conservation, high hydrophobicity, weak polarity, confined spatial geometry, and dynamic cryptic properties. These characteristics endow allosteric modulators with distinct advantages including high selectivity, functional tunability, and improved safety, making allosteric therapy a key direction in modern drug discovery.

MCE has curated nearly 1,000 structurally disclosed clinical-stage allosteric modulators. By analyzing allosteric protein–ligand complex structures from the PDB database, we extracted core pharmacophores and privileged scaffolds. Adopting a rational design strategy of “scaffold derivation + allosteric physicochemical filtering”, we performed secondary screening on the derived compounds strictly following the optimal physicochemical principles for allosteric binding based on universal allosteric pocket properties: molecular weight 300–500 Da, HBD ≤ 3, HBA = 3–8, PSA = 70–120 Ų, rotatable bonds ≤ 6, highly rigid scaffolds, cLogP = 1.0–3.8, and no strongly ionizable groups. The selected compounds exhibit high rigidity and shape complementarity, making them well-suited for targeting shallow, dynamic, and hydrophobic-dominated allosteric pockets.

This allosteric modulator library contains 4,315 structurally diverse, lead-like compounds dedicated to allosteric drug development, allosteric site targeting, and allosteric modulator screening. It is suitable for kinases, GPCRs, and other important drug targets. All compounds are analogs of clinical-stage allosteric modulators with a similarity score > 0.6, combining excellent druggability and allosteric binding potential. It provides a highly efficient tool for early-stage allosteric drug discovery.

Cysteine proteases (CPs), a key enzyme family regulating physiological metabolism and mediating pathological processes (e.g., abnormal bone resorption, tumour invasion, and pathogen infection), represent a core therapeutic target for disease intervention via the development of specific inhibitors. Currently reported CP covalent inhibitors encompass diverse structural types, including epoxides, aziridine, and activated double bonds (vinyl sulphones, α,β-unsaturated ketones), providing clear structural references for the development of novel CP covalent inhibitors.

This compound library contains multiple warheads that specifically target cysteine proteases, serving as a powerful tool for the efficient discovery of novel covalent inhibitors against this enzyme family.

Fragment-based drug discovery (FBDD) offers a strategic advantage by categorizing fragment hits according to their functional groups. This approach facilitates both the further optimization of these hits and the rational design of larger compounds through fragment combination. The amine functional group plays a vital role in drug development, as evidenced by its presence in many marketed drugs like Galantamine, Tacrine, and Rivastigmine. It is instrumental in enhancing solubility, improving bioavailability, and ensuring shelf-life stability—all critical factors for drug efficacy.

MCE offers a collection of 19,532 amine fragments for drug discovery. All of these compounds adhere to the Rule of Three (RO3) criteria for drug-likeness, which MCE offers a collection of 19,532 amine fragments for drug discovery, all of which stipulates a molecular weight ≤ 300 Da, ≤ 3 hydrogen bond donors, ≤ 3 hydrogen bond acceptors, and a cLogP ≤ 3.

MCE 50K Diversity Library consists of 50,000 lead-like compounds with multiple characteristics such as calculated good solubility (-3.2 < logP < 5), oral bioavailability (RotB <= 10), drug transportability (PSA < 120). These compounds were selected by dissimilarity search with an average Tanimoto Coefficient of 0.52. There are 36,857 unique scaffolds and each scaffold 1 to 7 compounds. What’s more, compounds with the same scaffold have as many functional groups as possible, which make abundant chemical spaces. This exceptionally diverse library is highly recommended for random screening against new as well as popular targets based its novel, diverse scaffolds, abundant chemical spaces and the convenience for subsequent modification.

Fragment-based drug discovery (FBDD) is well suited for discovering both drug leads and chemical probes of protein function; it can cover broad swaths of chemical space and allows the use of creative chemistry. Fragment-based drug discovery is well-established in industry and has resulted in a variety of drugs entering clinical trials, with two, vemurafenib and venetoclax, already approved. FBDD also has key attractions for academia. Notably, it is able to tackle difficult or novel targets for which no chemical matter may be found in existing HTS collections.

MCE designs a unique collection of 23,342 fragment compounds, all of which obey a heuristic rule called the “Rule of Three (RO3) ”, in which molecular weight ≤300 Da, the number of hydrogen bond donors (H-donors) ≤3, the number of hydrogen bond acceptors (H-acceptors) is ≤3 and cLogP is ≤3. This library is an important source of lead-like drugs.

19F-NMR has proved to be a detection mode in fragment-based drug discovery (FBDD) for studies of protein structure and interactions. 19F shows high sensitivity for NMR detection, and the exquisite sensitivity of 19F chemical shifts and linewidths to ligand binding all make it a valuable approach in FBDD.F (Fluorine) -Fragments can be used for 19F-NMR detection after binding to target proteins, and can be used as an effective 19F-NMR tool for FBDD.

MCE designs a unique collection of 5,123 F-fragments, all of which obey a heuristic rule called the “Rule of Three (RO3)”, in which molecular weight ≤300 Da, the number of hydrogen bond donors (H-donors) ≤3, the number of hydrogen bond acceptors (H-acceptors) is ≤3 and cLogP is ≤3. This F-fragments library is an important source of lead-like drugs.

Alzheimer’s Disease (AD) is a progressive degenerative brain disease which causes mental and physical decline, gradually resulting in death. Despite the significant public health issue that it poses, only few medical treatments have been approved for Alzheimer’s Disease (AD) and these act to control symptoms rather than alter the course of the disease. Discovery of new therapeutic approaches depends on the study of pathology of AD. Recent research findings have led to greater understanding of disease neurobiology in Alzheimer's Disease (AD) and identification of unique targets for drug development. Several important mechanisms have been proposed to explain the underlying pathology of AD, such as Amyloid cascade hypothesis, Tau hypothesis and Cholinergic hypothesis, etc.

MCE offers a unique collection of 2,065 compounds with anti-Alzheimer’s Disease activities or targeting the unique targets of AD. MCE Anti-Alzheimer’s Disease Compound Library is a useful tool for exploring the mechanism of AD and discovering new drugs for AD.

From the discovery of traditional Chinese medicine to modern antibiotics, natural products have played an important role in the drug development process. A review of all FDA-approved drugs shows that natural products and natural product-like compounds account for more than one-third of all approved drugs. Nearly half of that came from mammals, a quarter from microbes, and a quarter from plants. Over time, the proportion of microbial natural products and natural product derivatives in approved drugs has increased. Natural products have natural advantages in drug development and can be used as lead compounds in drug discovery for drug identification and mechanism research.

MCE provides a unique collection of 5,019 natural compounds and natural product-like compounds that contain saccharides and glycosides, phenylpropanoids, quinones, flavonoids, terpenoids and glycosides, steroids, alkaloid, phenols, acids and aldehydes. Natural product and natural product-like compounds library is a useful tool for drug discovery that can be used for high-throughput screening (HTS) and high-content screening (HCS).

A unique set of molecules containing mild electrophilic moieties that covalently interact with amino acid residues in the target protein. The diversity of our compounds for covalent drug discovery ranges from natural product-like scaffolds to macrocycles, creating multiple opportunities in hit generation for a selected target.

Hepatitis C virus (HCV) is a hepatotropic enveloped positive- strand RNA virus (family Flaviviridae) that infects the parenchymal cells of the liver. HCV infection is a significant public health burden. Globally, an estimated 71 million people have chronic hepatitis C virus infection. A significant number of those who are chronically infected will develop cirrhosis or liver cancer. To date, there is no vaccine against HCV, and combination pegylated alpha interferon (pIFN-) and ribavirin, the main standard-of-care treatment for HCV, is effective in only a subset of patients and is associated with a wide spectrum of toxic side effects and complications. More recently, new therapeutic approaches that target essential components of the HCV life cycle have been developed, including direct-acting antiviral (DAA) that specifically block a viral enzyme or functional protein and host-targeted agents (HTA) that block interactions between host proteins and viral components that are essential to the viral life cycle. However, the genetic diversity of HCV viruses and the stage of liver disease (i.e., cirrhosis) are revealing themselves as obstacles for effective, pan-genotypic treatments. There still exists a need for the discovery and development of new HCV inhibitors. In particular, since the future of HCV therapy will likely consist of a cocktail approach using multiple inhibitors that target different steps of infection, new antivirals targeting all steps of the viral infection cycle.

MCE offers a unique collection of 391 compounds with identified and potential anti-HCV activity. MCE Anti- Hepatitis C Virus Compound Library is a useful tool for discovery new anti-HCV drugs and other anti-infection research.

The high rates of morbidity and mortality caused by fungal infections are associated with the current limited antifungal arsenal and the high toxicity of the compounds. Additionally, identifying novel drug targets is challenging because there are many similarities between fungal and human cells. The most common antifungal targets include fungal RNA synthesis and cell wall and membrane components, though new antifungal targets are being investigated. Nonetheless, fungi have developed resistance mechanisms, such as overexpression of efflux pump proteins, overexpression and changes in drug targets and biofilm formation, emphasizing the importance of discovering new antifungal drugs and therapies. Due to the limited antifungal arsenal, researchers have sought to improve treatment via different approaches, such as the combination of antifungal drugs, development of new formulations for antifungal agents and modifications to the chemical structures of traditional antifungals, etc.

MCE offers a unique collection of 551 compounds with validated antifungal activities. MCE antifungal compound library is an effective tool for drug repurposing screening, combination screening and biological investigation.

Small molecule covalent inhibitors, or irreversible inhibitors, are a type of inhibitors that exert their biological functions by irreversibly binding to target through covalent bonds. Compared with non-covalent inhibitors, covalent inhibitors have obvious advantages in bioactivity, such that covalent warheads can target rare residues of a particular target protein, thus leading to the development of highly selective inhibitors and achieving a more complete and continued target occupancy in living systems. In recent years, the distinct strengths of covalent inhibitors in overcoming drug resistance had been recognized. However, toxicity can be a real challenge related to this class of therapeutics due to their potential for off-target reactivity and has led to these drugs being disfavored as a drug class. The drug design and optimization of covalent inhibitors has become a hot spot in drug discovery.

MCE Lead-like Covalent Screening Library offers a valuable resource of 1,049 lead-like compounds with commonly used covalent warheads. These warheads, such as acrylamide, activated terminal alkyne, acyloxymethyl ketone, and boronic acid, are capable of reacting with specific amino acid residues, including cysteine, lysine, serine, and histidine. The inclusion of these reactive warheads in the library allows researchers to explore the potential of covalent inhibition, a powerful approach in drug discovery.

Chemical probes are simply reagents with high potency, selectivity and cell-permeability which play important roles in both fundamental and applied biological research. In their most common application, chemical probes can establish the tractability of a specific target. They are used to interrogate the relationship between a target and its phenotype (biological tractability) as well as an ability to modulate that phenotype using a small molecule. Otherwise, chemical probes also have had a major impact in enabling and accelerating discoveries along the path to pioneer medicines. They have helped to improve the understanding of targets and pathways and have created opportunities for proprietary drug discovery efforts to an extent that would not have been possible otherwise.

MCE provides a unique collection of 281 chemical probes with high potency (at least 100 nM potency), selectivity (at least 10-fold selectivity against any other target) and cell-permeability (at least 10 μM potency). MCE Chemical probe library is a useful tool for target identification and mechanism research.

The composition of endogenous metabolite compounds is affected by the upstream influence of the proteome and genome as well as environmental factors, lifestyle factors, medication, and underlying disease. Therefore, metabolites have been described as proximal reporters of disease because their abundances in biological specimens are often directly related to pathogenic mechanisms. In more recent years, metabolomics approach has been adopted or suggested to be used in various research areas including drug discovery, neurosciences, agriculture, food and nutrition, and environmental sciences.

MCE owns a unique collection of 795 human endogenous metabolites, all of which are derived from human issues. This library is a powerful tool for metabonomics research and metabolism-related drug discovery.

Targeted protein degradation(TPD) is a novel and promising approach to new drug discovery and development. It shows great potential for treating diseases with “undruggable” pathogenic protein targets and for overcoming drug resistance. Molecular glues and PROTACs are both targeted protein degraders that have attracted the most attention.

Molecular glues are small molecular degraders that mainly induce novel interaction between an E3 ligase and a target protein to form a ternary complex, leading to protein ubiquitination and subsequent proteasome degradation. Compared with PROTACs, molecular glues generally possess more favorable drug-like properties, such as lower MW, higher cell permeability, and better oral absorption. Molecular glues are emerging as a promising new therapeutic strategy.

MCE supplies a unique collection of 105 molecular glues which target various proteins. MCE Molecular Glue Compound Library is a useful tool to conduct scientific research and disease mechanism study.

Macrocycles, molecules containing 12-membered or larger rings, are receiving increased attention in small-molecule drug discovery. The reasons are several, including providing access to novel chemical space, challenging new protein targets, showing favorable ADME- and PK-properties. Macrocycles have demonstrated repeated success when addressing targets that have proved to be highly challenging for standard small-molecule drug discovery, especially in modulating macromolecular processes such as protein–protein interactions (PPI). Otherwise, the size and complexity of macrocyclic compounds make possible to ensure numerous and spatially distributed binding interactions, thereby increasing both binding affinity and selectivity.

MCE offers a unique collection of 448 macrocyclic compounds which can be used for drug discovery for high throughput screening (HTS) and high content screening (HCS). MCE Macrocyclic Compound Library is a useful tool for discovering new drugs, especially for “undruggable” targets and protein–protein interactions.

Oceans cover more than 70% of the Earth’s surface and host a huge species diversity. Marine organisms are considered the most recent source of bioactive natural products after terrestrial plants and nonmarine microorganisms. Marine biological sources are taxonomically diverse and include sponges, tunicates, corals, mollusks, fungi, and sediment-derived bacteria.

Marine organisms can produce a plethora of small molecules with novel chemical structures and potent biological properties, being a rich source for the discovery of pharmacologically active compounds, already with several marine-derived agents approved as drugs. Ziconotide, a peptide originally discovered in a tropical cone snail, was the first marine-derived compound to be approved in the United States in December 2004 for the treatment of pain. Then, in October 2007, Trabectedin became the first marine anticancer drug to be approved in the European Union.

MCE offers a unique collection of 63 marine-sourced natural products which can be used for drug discovery for high throughput screening (HTS) and high content screening (HCS). MCE marine-sourced natural product library is an important source for drug discovery and development.

Currently,the incidence and mortality rates of clinical fungal infections remain high. Existing antifungal drugs are limited in variety and associated with numerous adverse effects, creating an urgent demand for the development of novel antifungal agents. Antifungal compound libraries can support the screening and development of new antifungal drugs.

The mechanisms of action of antifungal drugs cover key processes such as fungal cell membrane synthesis, cell wall synthesis, and cell division. They exert fungicidal or fungistatic effects by specifically targeting different molecular pathways. This library includes a variety of core analogs of antifungal drugs, making it adaptable to antifungal research in diverse scenarios. It can be used for the high-throughput screening of novel antifungal drug candidates, enabling the rapid identification of compounds with potential antifungal activity and facilitating the elucidation of drug-target interactions and resistance mechanisms. Additionally, it supports the screening of compounds and combinations that reverse drug resistance, thereby uncovering the novel antifungal potential of existing compounds.

The library comprises 8350 compounds with a well-defined screening strategy. The core sources of the compounds include analogs of known antifungal active moleculeswith a similarity score of ≥ 0.6 MCE has collected more than 500 antifungal molecules.All screened compounds conform to lead-like physicochemical properties, exhibiting both structural diversity and drug-like characteristics, and providing valuable support for the research and development of novel antifungal drugs.

Peptidomimetics are compounds whose essential elements (pharmacophore) mimic a natural peptide or protein in 3D space and which retain the ability to interact with the biological target and produce the same biological effect. Peptidomimetics are designed to circumvent some of the problems associated with a natural peptide: e.g. stability against proteolysis (duration of activity) and poor bioavailability. Certain other properties, such as receptor selectivity or potency, often can be substantially improved. The design and synthesis of peptidomimetics are most important because of the dominant position peptide and protein-protein interactions play in molecular recognition and signaling, especially in living systems. Hence mimics have great potential in drug discovery.

MCE Peptidomimetic Library contains 370 compounds including peptoid, α-helix mimetics, β-turn/sheets mimetics, etc. This library is an indispensable tool of structure-activity relationships in drug discovery.

Antibody-Drug Conjugates (ADCs), a new class of treatment for cancer, are composed with a monoclonal antibody, a linker and a cytotoxic agent also referred to as a payload. To date, several ADCs have received market approval and more than 60 ADCs are currently in clinical trials. ADCs are one of the fastest growing classes of oncology drugs worldwide.

The payload or cytotoxic agent is the most important unit in the ADC. ADC has the capability to kill cancer cell depending on the potency of the payload. MCE provides 115 highly potent cytotoxins that contain auristatin derivatives, maytansinoids, calicheamicin, duocarmycin, pyrrolobenzodiazepines (PBDs), etc.

Antitussive and antiasthmatic method is a type of treatment strategy in traditional Chinese medicine, mainly used to alleviate symptoms such as coughing and asthma. These symptoms may be caused by various factors, such as: Bronchial asthma, chronic obstructive pulmonary disease, asthmatic bronchitis, cough-induced asthma, and others. Based on existing research in traditional Chinese medicine, many types of Chinese medicinal herbs showed antitussive and antiasthmatic effects. For example: Ardisiae Japonicae Herba, Ginkgo Semen, Amygdalus Communis Vas, Farfarae Flos, Viticis Cannabifoliae Fructus, Eriobotryae Folium etc. Therefore, the active ingredients derived from these traditional Chinese medicine have high medicinal value and have the potential to be developed into drugs for related diseases.

MCE can provide 861 active ingredients that can be obtained from traditional Chinese medicine with antitussive and antiasthmatic functions, which can be applied to drug development and research on disease mechanisms.

Cysteine proteases (CPs), a key enzyme family regulating physiological metabolism and mediating pathological processes (such as abnormal bone resorption, tumour invasion, and pathogen infection), represent a core therapeutic target for developing specific inhibitors in disease intervention. Currently reported CP inhibitors primarily achieve their inhibitory function by precisely binding to CP active pockets (e.g., S1-S4 non-primed regions or S1'-S2' primed regions) and forming covalent/non-covalent interactions with the active site cysteine residues, providing clear structural references for the development of novel inhibitors.

This compound library, designed based on the core strategy of "similarity-based known active structures", contains over 200 cysteine protease inhibitors. Leveraging AI-driven molecular screening technology, it retains the critical pharmacological and shape features of reported CP inhibitors, serving as a specialized tool for efficiently discovering novel cysteine protease inhibitors.

Owing to the widespread transmission and frequent mutation of viral diseases, as well as the continuous emergence of new viruses and drug-resistant strains, antiviral drug development is facing increasingly stringent requirements. Antiviral compound libraries serve as important tools for drug screening, mechanism research and development, enabling the discovery and investigation of various antiviral drugs.

These compounds act through diverse antiviral mechanisms, targeting key steps in viral replication, assembly and invasion. They exert antiviral effects by inhibiting viral nucleic acid synthesis, blocking viral protein processing, and preventing viral binding to host cells. This library covers various types of antiviral compounds, including nucleosides, non-nucleosides, protease inhibitors and integrase inhibitors. It supports research on influenza virus, herpes virus, hepatitis virus, emerging respiratory viruses and other pathogens, and enables high-throughput screening of novel antiviral candidates to rapidly identify potential active compounds against diverse viruses. It also facilitates mechanistic studies to elucidate drug-target interactions and viral resistance mechanisms, and supports the screening of effective compounds against mutant strains for research on viral variation and drug resistance.

This antiviral library consists of 6,804 compounds with lead-like physicochemical properties. The core sources of the compounds include analogs of known antiviral molecues with a similarity score ≥ 0.6. MCE has collected more than 1450 antiviral molecules. As a small-molecule collection with both activity potential and structural modifiability, it provides strong support for antiviral drug research and development.

Natural product have great diversity and structural complexity of scaffolds. And the number of their drugs represents a large number of sources of new pharmacological entities, so natural products are of great significance in drug discovery. The Dictionary of Natural Products (DNP) shows that natural products mainly come from plants, animals and microorganisms, and animal sources are the second important source of natural products. Animal derived natural products exist to varying degrees in almost all forms of animals, generally secondary metabolite extracted from organisms.

MCE provides a unique collection of 995 animal-sourced natural products. MCE Animal-Sourced Natural Product Library is a useful tool for drug discovery that can be used for high throughput screening (HTS) and high content screening (HCS).

Neurodegenerative diseases are characterised by progressive dysfunction and death of neurons, such as Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis (MS). Neuroprotection is an approach to preserve neurons so that neurons cannot be hurt by different pathological factors in neurodegenerative diseases. Neuroprotectors are some agonists and antagonists targeting some key targets in neuroprotactive signal pathways, such as calcium and sodium channel blockers, GABA receptor agonists, NMDA receptor Antagonists, etc. Current neuroprotectors cannot reverse existing damage, but they may protect against further nerve damage and slow down any degeneration of the central nervous system (CNS) and still play important roles in the treatment of neurodegenerative diseases.

MCE offers a unique collection of 1,748 compounds with potential neuroprotective activities. These compounds mainly act on some key targets in neuroprotetive signal pathways, such as calcium channel, sodium channel, adenosine A1 receptor, etc. MCE Neuroprotective Compopund Library is a useful tool in neuroprotective drug discovery.

The incidence and significance of central nervous system diseases are increasing at an alarming rate all over the world. Although substantial research efforts have been applied to develop new CNS-active drugs, only a few CNS disorders are addressed satisfactorily, while the remaining ones pose significant clinical challenges. Blood-brain barrier (BBB) permeability is one of the most important limiting factors in the design and development of novel CNS-targeted pharmaceuticals for the treatment of neurological disorders.

Carefully selected from the HTS Compound Collection to meet the parameters optimized for high BBB-permeability, our CNS Focused Screening Library comprising over 30,300 structurally-diverse and potentially CNS-active screening compounds. This original Screening Compound Library is aimed at supporting CNS drug design projects and HTS efforts in search for novel neurotherapeutics.

Covalent inhibitors are small molecules that can bind specifically to target proteins through covalent bonds and inhibit their biological functions. Although for a long time, covalent targeting has been playing a subordinate role in drug discovery, with an increasing number of reports on successful clinical applications of such drugs, the potential of these agents is now being acknowledged.

Covalent ligands rely on reactive groups (“warheads”), and new warheads are key to expanding the scope of covalent modalities. Through careful selection, we constructed a structural filter containing over 110 electrophilic groups. By analyzing the electrophilic fragments selected by the structural filter, we removed any molecules with trivial or undesirable structural features. Ultimately, we obtained 8,900 fragment molecules with covalent modification potential, which can target various reactive amino acid residues and can be used for fragment-based covalent drug discovery.

Cancer is the second leading cause of death worldwide and a serious threat to human health. Multiple treatments have been developed for cancer treatment, but new anti-cancer drugs still need to be developed urgently. Approved drugs, have well-characterized bioactivities, safety and bioavailability properties, will dramatically accelerate drug development.

MCE offers a unique collection of 1,520 approved drugs with anti-cancer activity, which can be used for discovery of new anti-cancer drugs or as positive compounds used for anti-cancer research.

MCE In vivo OptiLNP RNA Transfection Reagent (Lung-targeted) is a ready-to-use transfection reagent based on LNP technology. It is designed for the efficient transfection of mRNA and short-chain RNA via intravenous injection in experimental animals.

MCE In vivo OptiLNP RNA Transfection Reagent (Liver-targeted) is a ready-to-use transfection reagent based on LNP technology. It is designed for the efficient transfection of mRNA and short-chain RNA via intravenous injection in experimental animals.

MCE HP PolyFast Transfection Reagent is a novel cationic polymer transfection reagent for DNA and RNA transfection.

MCE Human Brain Organoid (Expansion) Kit contains Human Brain Organoid Expansion Basal Medium and Human Brain Organoid Expansion Culture Supplements. This kit enables the efficient in vitro generation of human forebrain organoids (hFBs). Within this culture system, human brain tissue can spontaneously form organoid structures that faithfully recapitulate key features of in vivo cellular heterogeneity and complex tissue organization.

MCE ECM Gentle Dissociation Solution is a gentle ECM-degrading enzyme mixture derived from marine bacteria and Bacillus species, specifically formulated for efficient and low-damage digestion of in-vitro cell systems. It selectively degrades extracellular matrix components while minimizing disruption to the cell membrane and intercellular junctions, thereby significantly reducing mechanical stress during dissociation.

MCE Mouse Fetal Brain Organoid (Expansion) Kit contains Mouse Fetal Brain Organoid Expansion Basal Medium and Mouse Fetal Brain Organoid Expansion Culture Supplement . This kit enables the efficient in vitro generation of mouse fetal brain organoids (mFBs). Within this culture system, mouse fetal brain tissue can spontaneously form organoid structures that faithfully recapitulate key features of in vivo cellular heterogeneity and complex tissue organization.

MCE siRNA/miRNA Transfection Reagent is a novel cationic polymer transfection reagent for siRNA and miRNA transfection. The 1 mL is defined as the base specification. All larger sizes correspond to incremental volumes of this base.

MCE Human Neuroblastoma Cell Culture Medium is specially designed to promote the in vitro growth of primary human neuroblastoma cells.

MCE Human Acute Myeloid Leukemia Cell Culture Medium is specially designed to promote the in vitro growth of primary human acute myeloid leukemia cells.

MCE T-Cell Expansion Medium (Serum-Free) is a specialized culture medium formulated for the in vitro cultivation and robust expansion of human T lymphocytes without the need for serum.

MCE Anti-Flag Affinity Gel is used for immunoprecipitation (IP) or protein purification of specific Flag-tagged (DYKDDDDK) proteins expressed in bacterial and mammalian cells and in vitro expression systems.

MCE Trypan Blue Staining Solution (0.4%) is suitable for viability assessment of most adherent and suspension cell lines. It is commonly used for cell culture quality control, evaluation of cellular responses following drug treatment, and viability measurements after cell thawing and recovery.

MCE ECM Gentle Dissociation Solution is a gentle ECM-degrading enzyme mixture derived from marine bacteria and Bacillus species, specifically formulated for efficient and low-damage digestion of in-vitro cell systems. It selectively degrades extracellular matrix components while minimizing disruption to the cell membrane and intercellular junctions, thereby significantly reducing mechanical stress during dissociation. This product is compatible with a wide range of cell types, including stem cell colonies, primary cells, neural cells, and organoids, and is particularly well suited for gentle yet effective dissociation of brain organoids and other complex 3D structures.

MCE Sirius Red Staining Kit consists of hematoxylin staining solution and Sirius Red staining solution and is mainly used to observe abnormal collagen deposition or fibrosis in various pathological tissues. Under a conventional light microscope, collagen fibers in tissues such as the heart and blood vessels appear red. Under polarized light microscopy, this method is useful for the classification and evaluation of different types of fibrotic lesions.

MCE Anti-GST Magnetic Beads are used for immunoprecipitation (IP) of specific GST-tagged proteins expressed in bacterial and mammalian cells and in vitro expression systems. The 1 mL is defined as the base specification. All larger sizes correspond to incremental volumes of this base.

MCE Anti-His Magnetic Beads are used for immunoprecipitation (IP) of specific His-tagged proteins expressed in bacterial and mammalian cells and in vitro expression systems. The 1 mL is defined as the base specification. All larger sizes correspond to incremental volumes of this base.

MEM Non-essential Amino Acid Solution (100×) has been filtered and can be used directly. It adds nutrients and reduces the biosynthetic burden on cell in vitro. The 100 mL is defined as the base specification. All larger sizes correspond to incremental volumes of this base.

MCE Anti-HA Magnetic Beads are used for immunoprecipitation (IP) of specific HA-tagged proteins expressed in bacterial and mammalian cells and in vitro expression systems.The 1 mL volume is defined as the base specification. All larger sizes correspond to incremental volumes of this base.

MCE Anti-c-Myc Magnetic Beads are used for immunoprecipitation (IP) of specific c-Myc-tagged proteins expressed in bacterial and mammalian cells and in vitro expression systems. The 1 mL is defined as the base specification. All larger sizes correspond to incremental volumes of this base.

MCE ATPase Staining Kit for Muscle Fibers (Calcium Activation Method) is based on the hydrolysis of ATP by ATPase, which generates ADP and inorganic phosphate. Phosphate combines with calcium ions to form colorless calcium phosphate precipitates. Calcium phosphate is then treated with cobalt chloride to form cobalt phosphate, which, after treatment with sulfide solution, results in the formation of brown-black cobalt sulfide precipitates at the enzyme activity sites.

MCE Anti-HA Magnetic Beads (1 μm) are used for immunoprecipitation (IP) of specific HA-tagged proteins expressed in bacterial and mammalian cells andin vitro expression systems. The 1 mL is defined as the base specification. All larger sizes correspond to incremental volumes of this base.

MCE Anti-Flag Magnetic Beads are used for immunoprecipitation (IP) of specific Flag-tagged (DYKDDDDK) proteins expressed in bacterial and mammalian cells and in vitro expression systems, and also suitable for Co-immunoprecipitation and purification of Flag-tagged protein. The 1 mL is defined as the base specification. All larger sizes correspond to incremental volumes of this base.

MCE Modified Van Gieson Staining Kit employs Celestine Blue and Mayer’s hematoxylin for nuclear staining, providing clearer and more stable nuclear visualization while facilitating longer preservation of stained sections. Ponceau S is used for collagen fiber staining, offering stable coloration and strong resistance to fading. This method enables effective differentiation between collagen fibers and muscle fibers, and can assist in distinguishing collagen fiber–derived tumors from myogenic tumors to a certain extent. It is also suitable for observing tissue or organ injury, repair processes, and the degree of fibrosis.

MCE 2-Color Tracking SYBR qPCR Master Mix (Universal) is a 2× concentration premixed reagent utilizing a special performance-enhanced Taq DNA polymerase protected via a hot-start activation technique, and optimized qPCR buffer system to perform SYBR Green I based quantitative PCR (qPCR). The 100 rxns is defined as the base specification. All larger sizes correspond to incremental volumes of this base.

MCE In vivo OptiLNP RNA Transfection Reagent (Systemic Effect) is a ready-to-use transfection reagent based on LNP technology. It is designed for the efficient transfection of mRNA and short-chain RNA in experimental animals. The RNA functions systemically.

MCE In vivo OptiLNP RNA Transfection Reagent (Local Effect) is a ready-to-use transfection reagent based on LNP technology. It is designed for the efficient transfection of mRNA and short-chain RNA in experimental animals. The RNA functions locally.

MCE Rhodamine Phalloidin is Phalloidin conjugated to the fluorescent dye Tetramethylrhodamine. Phalloidin binds F-actins with high selectivity while Rhodamine provides stable and bright orange fluorescence.

MCE Fluorescein Phalloidin is Phalloidin conjugated to the fluorescent dye Fluorescein. Phalloidin binds F-actins with high selectivity while Fluorescein provides stable and bright green fluorescence.

MCE AMCA Phalloidin is Phalloidin conjugated to the fluorescent dye AMCA. Phalloidin binds F-actins with high selectivity while AMCA provides stable and bright blue fluorescence.

MCE Alcian Blue Staining Solution (pH 1.0) is commonly used for selective detection of sulfated mucins in histological research, including cartilage staining, mucin type differentiation, and aiding in the identification of mucinous epithelial tumors.

MCE G418 Selective Antibiotic, Sterile (50 mg/mL) is an aminoglycoside antibiotic produced by Micromonospora rhodorangea. It acts by binding to the 80S subunit of the bacterial ribosome, thus inhibiting protein synthesis in both prokaryotic and eukaryotic cells.