High toxicity

A diverse compound library with favorable ADMET properties (Absorption, Distribution, Metabolism, Excretion, and Toxicity) is crucial in drug discovery. Early evaluation of ADMET properties allows for the exclusion of molecules with unfavorable profiles at the initial stages, thereby reducing the risk of late-stage development failures, lowering R&D costs, and accelerating optimization of lead compounds. Based on predictions from ADMET-related AI algorithms, the compounds in this library are predicted to exhibit favorable oral bioavailability (F > 30%), reasonable plasma protein binding (PPB < 98%), minimized CYP3A4 inhibition potential (inhibition probability < 50%, CYP3A4 is the most critical drug-metabolizing enzyme in the cytochrome P450 family) , low toxicity profiles, with 140 potentially toxic substructures pre-identified and excluded via substructure searching to eliminate compounds containing hazardous fragments. The diversity library enables broad applicability in high-throughput screening (HTS) and high-content screening (HCS).

In drug discovery and development (R&D) area, target binding and druggability optimization are core processes. Among these attributes, high solubility is critical for a compound to achieve druggability, as it directly impacts the progress of drug R&D. Superior solubility ensures the rapid dissolution and uniform distribution of drug molecules in vivo, thereby enhancing bioavailability and effectively mitigating issues such as suboptimal efficacy, increased dosage requirements, or exacerbated toxic and side effects arising from insufficient solubility.

From the perspective of medicinal chemistry, high-solubility drug fragments serve as high-quality "molecular building blocks". Based on these fragments, lead compounds with potential druggability can be rapidly screened out, which significantly shortens the drug R&D cycle and reduces R&D costs. Meanwhile, the high-solubility drug fragment library can provide diverse options for drug development in different therapeutic areas, offer solutions for the solubility defects of existing clinical drugs, and facilitate the development of novel, highly effective targeted drugs with higher bioavailability and better safety profiles.

MCE has collected and compiled 2,527 experimentally validated small-molecule fragments with high solubility. These fragments can be directly used for drug molecular design, providing high-quality pre-validated solubility fragments that significantly improve the efficiency of lead compound screening and accelerate the progress of drug R&D.

Antimicrobial Peptides (AMPs), also known as antimicrobial peptides or antibiotic peptides, are a class of polypeptides encoded by specific genes in various biological cells and induced by external stimuli. They exhibit broad-spectrum bioactivity against bacteria, fungi, viruses, protozoa, and even tumor cells. AMPs serve as crucial effector molecules in the host's innate immune system.Due to their wide antimicrobial spectrum, low toxicity to normal cells of higher animals, high safety profile, low tendency to induce resistance, and additional benefits such as immune enhancement and antioxidant effects, antimicrobial peptides hold significant promise in new drug development.

MCE offers 58 types of antimicrobial peptides, which can be applied in high-throughput screening for research in anti-infection therapies, immunotherapy, anticancer drug development, and agricultural disease control.

Most of the drugs that are available in the marketplace are administered via the oral route, which is a convenient and cost effective route of administration. Thus, oral bioavailability is one of the key considerations in drug design and development. A high oral bioavailability reduces the amount of an administered drug necessary to achieve a desired pharmacological effect and therefore could reduce the risk of side-effects and toxicity. A poor oral bioavailability can result in low efficacy and higher inter-individual variability and therefore can lead to unpredictable response to a drug. Low oral bioavailability in clinical trials is a major reason for drug candidates failing to reach the market.

MCE offers a unique collection of 5,259 compounds with confirmed high oral bioavailability. MCE Orally Active Compound Library is a useful tool for discovering new drugs with oral bioavailability.

Drug-induced liver injury (DILI; also known as drug-induced hepatotoxicity) is caused by medications (prescription or OTC), herbal and dietary supplements (HDS), or other xenobiotics that result in abnormalities in liver tests or in hepatic dysfunction that cannot be explained by other causes. Drugs are an important cause of liver injury. Drug-induced hepatic injury is the most common reason cited for withdrawal of an approved drug.

DILI is thought to occur via several different mechanisms. Among these are direct impairment of the structural (e.g., mitochondrial dysfunction) and functional integrity of the liver; production of a metabolite that alters hepatocellular structure and function; production of a reactive drug metabolite that binds to hepatic proteins to produce new antigenic drug-protein adducts, which are targeted by hosts’ defenses (the hapten hypothesis); and initiation of a systemic hypersensitivity response (i.e., drug allergy) that damages the liver.

MCE Drug-induced Liver Injury (DILI) Compound Library contains a unique collection of 641 hepatotoxicity causing compounds and is a powerful tool to research DILI and other drug toxicities. This library can be used to understand the mechanisms of DILI, identify biomarkers for early DILI prediction, and allow timely recognition during drug development, thus finally achieving successful DILI prevention and assessment in the pre-marketing phase.

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.

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.

Ionizable lipids are a class of specialized, functional lipid molecules with pH-sensitive charge characteristics. They are primarily divided into two major categories: ionizable cationic lipids and ionizable anionic lipids, though the term typically specifies ionizable cationic lipids within the biomedical field. Structurally, these lipids consist of an ionizable hydrophilic headgroup, a biodegradable linker, and hydrophobic tails. Their primary application is serving as the key delivery vehicle in lipid nanoparticles (LNPs) to encapsulate negatively charged nucleic acid macromolecules, such as mRNA vaccines, siRNA therapeutics, and CRISPR gene-editing components. In a physiological, neutral environment, they remain electrically neutral to minimize systemic toxicity and prolong circulation time. Upon entering the acidic microenvironment of cellular endosomes, however, they undergo protonation to become positively charged, thereby inducing membrane fusion and enabling the highly efficient intracellular release of the nucleic acid cargo. Consequently, they serve as the technological cornerstone for bringing nucleic acid therapies into clinical application.

To accelerate the translational process of cutting-edge nucleic acid drugs, MCE has meticulously constructed an ionizable lipid compound library containing 95 high-performance molecules, aiming to provide researchers and pharmaceutical professionals with a high-throughput, multi-dimensional lipid screening platform.

Withdrawal or delisting drugs refer to drugs that are recalled or discontinued from the market due to low efficiency, serious side effects, financial and regulatory problems and other reasons. Once the drug is withdrawn from the market, it will cause heavy losses to the original research company that invested a lot of time, finance and other costs to develop the drug.

Adverse drug reaction (ADR) is the main reason for drug withdrawal from the market. ADR refers to the unexpected effects caused by the reasons such as the target-directed interaction during the treatment. However, studying the mechanism of these ADRs may just be a breakthrough in finding new indications. For example, thalidomide, the protagonist of the drug damage event that caused numerous "seal babies" deformed infants, was found to be due to the degradation of a transcription factor - SALL4 after delisting, which made thalidomide have a new clinical application. In 1998, it was approved by FDA for the treatment of leprosy nodular erythema, and in 2006, it was approved for the treatment of multiple myeloma. ADR study of delisted drugs can not only avoid the loss of drug development in advance but also bring hope to new indications.

MCE has sorted out 230 drug compounds withdrawn from the market through FDA, EMA and other authoritative platforms. Each compound has withdrawal records in at least one country/market. It is a useful tool for conducting research on drug side effects or drug toxicity mechanisms and discovering new indications of drugs.

Mitochondria, as the main place of energy supply in life, is essential to maintain normal life activities. Mitochondrial dysfunction is associated with common diseases, such as cardiovascular diseases, neurodegenerative diseases, diabetes and cancer. The heart, brain and liver rely heavily on mitochondrial function as the main organs for drug metabolism. In addition, mitochondria is also a target of many drugs, some of which induce organotoxicity by inducing mitochondrial toxicity.

MCE contains 535 mitochondrial toxic compounds, which can be used as tool compounds for drug development and disease mechanism research.

Ion channels are key proteins on the cell membrane that regulate the flow of ions across membranes. They participate in nearly all physiological processes, including nerve conduction, muscle contraction, heart rhythm, and pain perception. Abnormalities in their function can lead to various serious diseases such as arrhythmia, epilepsy, hypertension, neuropathic pain, and cancer. Therefore, ion channels are highly valuable drug targets—over 15% of approved drugs target ion channels currently, demonstrating their irreplaceable therapeutic value in cardiovascular, neurological, and analgesic fields.

MCE has collected a library of over 5,000 reported ion channel-related bioactive compounds targeting major sites such as Na+ channels, K+ channels, Ca2+ channels, GABA receptors, iGluRs, and others. Using AI models, these compounds are characterized through both 2D representations (molecular fingerprints, pharmacophores) and 3D representations (3D conformation) to screen for a collection of lead-like compounds highly similar to known active molecules. Additionally, an hERG channel prediction algorithm integrating XGB and ISE mapping strategy is employed to assess and exclude potential cardiotoxicity in the library.. This step significantly reduces safety risks in subsequent screenings, particularly for ion channel drug development related to cardiovascular systems (e.g., Nav1.5, Cav1.2), effectively minimizing failures due to hERG inhibition and serving as a valuable tool for ion channel drug screening.

Biotoxins, also referred to as natural toxins, are chemical substances produced by plants, animals, or microorganisms that exert toxic effects on other living organisms. Due to unique biological activities, biotoxins have been widely applied in molecular biology, physiology, pharmacology, and the clinical diagnosis and treatment of various human diseases, becoming an important source of natural drug development. Biotoxins can specifically bind to and interfere with intracellular signaling molecules or receptors, thereby altering cellular signaling processes. Leveraging this characteristic, biotoxins can be used to study the regulatory mechanisms of cellular signaling pathways. For example, neurotoxins such as snake venom peptides can be used to investigate the functional regulation of neurotransmitter receptors and ion channels. Additionally, biotoxins have demonstrated significant potential in drug development across various fields, including neurological diseases, cardiovascular diseases, anticoagulation, and anti-cancer therapies. With advancements in high throughput screening, structural optimization, and antibody-toxin conjugation technologies, numerous biotoxins or their structural analogs have been successfully brought to market, such as Ziconotide, Captopril, Bivalirudin, and Eptifibatide.

MCE offers 90 types of biotoxins, including neurotoxins, cardiotoxins, mycotoxins, and more.

Macrocyclic compounds (≥12-atom cyclic small molecules/peptides) have unique physicochemical properties. They form preorganized conformations with high binding affinity/selectivity, target traditional small-molecule-inaccessible proteins, and bridge small-molecule drugs and biological agents. As key protein phosphorylation enzymes, kinases are linked to tumors, COPD, etc., and are critical therapeutic targets. Traditional small-molecule kinase inhibitors lack selectivity, causing off-target toxicity, low bioavailability, and acquired resistance. Macrocycles’ semi-rigid structure restricts conformations, boosts binding selectivity, optimizes pharmacokinetics, and makes macrocyclization a core kinase inhibitor optimization strategy.

Thousands of bioactive macrocycles were curated from ChEMBL. Via Transformer, macrocyclization was converted into a chemical language translation task, enabling end-to-end macrocycle generation from linear precursors with simplified inputs. Macformer achieves efficient, automated linear molecule macrocyclization via deep learning; generated macrocycles have diversity, novelty, biocompatibility, and cover broader chemical space.

MCE collected thousands of marketed/clinical kinase inhibitors, using their fragments for macrocyclization to generate derivatives. After evaluating synthetic accessibility and physicochemical properties, a million-scale virtual macrocyclic library was built for kinase-related virtual and AI-driven screening.

Macrocyclic compounds (≥12-atom cyclic small molecules/peptides) have unique physicochemical properties. They form preorganized conformations with high binding affinity/selectivity, target traditional small-molecule-inaccessible proteins, and bridge small-molecule drugs and biological agents. As key protein phosphorylation enzymes, kinases are linked to tumors, COPD, etc., and are critical therapeutic targets. Traditional small-molecule kinase inhibitors lack selectivity, causing off-target toxicity, low bioavailability, and acquired resistance. Macrocycles’ semi-rigid structure restricts conformations, boosts binding selectivity, optimizes pharmacokinetics, and makes macrocyclization a core kinase inhibitor optimization strategy.

Thousands of bioactive macrocycles were curated from ChEMBL. Via Transformer, macrocyclization was converted into a chemical language translation task, enabling end-to-end macrocycle generation from linear precursors with simplified inputs. Macformer achieves efficient, automated linear molecule macrocyclization via deep learning; generated macrocycles have diversity, novelty, biocompatibility, and cover broader chemical space.

MCE collected thousands of marketed/clinical kinase inhibitors, using their fragments for macrocyclization to generate derivatives. After evaluating synthetic accessibility and physicochemical properties, a million-scale virtual macrocyclic library was built for kinase-related virtual and AI-driven screening.

MCE Masson Staining Kit can simultaneously stain various tissue components, such as cell nuclei, collagen fibers, and muscle fibers. It features low toxicity, environmental friendliness, simple operation, and stable performance. The staining results show clear coloration and high contrast. The stained sections can be stored for long periods with minimal fading, facilitating long-term preservation and image analysis. This kit is widely used in studies of connective tissue, muscle tissue, and collagen fibers, and is suitable for histological observation and related pathological analyses.

MCE Modified Masson Staining Kit employs Celestine Blue hematoxylin for light nuclear staining, offering shorter differentiation time compared to conventional methods. It features low toxicity, environmental friendliness, simple operation, and stable performance. The staining results show clear coloration and high contrast. The stained sections can be stored for long periods with minimal fading, facilitating long-term preservation and image analysis. This kit is widely used in studies of connective tissue, muscle tissue, and collagen fibers, and is suitable for histological observation and related pathological analyses.

MCE PEI Transfection Reagent is designed based on 25 kDa PEI. It has high-efficiency, low-toxicity, strong-stability, and is suitable for many cell types, such as HEK-293、HEK-293T、CHO-K1、COS-1、COS-7、NIH/3T3、Sf9、HepG2 and HeLa et, even some hard-to-transfect cells. It can also be applied to large-scale recombinant protein expression and virus production. The 1 mL is defined as the base specification. All larger sizes correspond to incremental volumes of this base.