2-amino-6-chloropurine-9-beta-d-2-deoxy-3-5-di-o-benzoyl-2-fluoro-ara

Amino acids are indispensable building blocks for life activities and are widely involved in key biological processes such as cell signal transduction, energy metabolism, gene expression regulation, and neurotransmitter synthesis. As components of proteins, 20 kinds of amino acids make up over one million kinds of proteins in the human body. These amino acids can be classified into nine types of "essential amino acids" that the human body cannot synthesize on its own and must obtain from food, as well as eleven types of "non-essential amino acids" that the human body can synthesize on its own.

MCE offers 20 kinds of amino acids provided which can be applied in research fields such as the study of amino acid metabolic processes, metabolite identification, food/cosmetic ingredient research, and the development of nutritional supplements.

Amino acids are the fundamental components that sustain life activities, playing roles in ATP generation, promoting nucleotide synthesis, and maintaining cellular redox balance. Moreover, dysregulation of amino acid consumption is a significant potential regulatory mechanism leading to impaired anti-tumor immunity in immune cells. The normal functioning of immune cells relies on amino acid metabolic pathways to obtain energy and materials, and upon activation, they reprogram their metabolism to support growth, proliferation, and effector functions. Additionally, metabolic disorders of specific amino acids (such as branched-chain amino acids, glutamine, and arginine) can exacerbate mitochondrial dysfunction and oxidative stress, thereby promoting myocardial fibrosis and cardiac cell damage. Therefore, conducting research related to amino acid metabolism holds promise for discovering potential drugs for diseases related to cancer, immunity, and metabolism.

MCE can provide 200 kinds of metabolites of amino acid metabolic pathways, which can be used for drug screening in various diseases such as cancer, immune disorders, metabolic diseases, mitochondrial-targeted diseases

Unnatural amino acids (UAAs), also referred to as non-canonical amino acids (ncAAs) or non-proteinogenic amino acids, are a class of amino acids that are distinct from the 20 standard natural amino acids. They can be obtained through chemical synthesis, biosynthesis, and other approaches, with structural diversity far exceeding that of natural amino acids. UAAs are mainly including naturally occurring non-canonical amino acids, chemically synthesized amino acids, and biosynthetic amino acids, which provide a molecular basis for protein function design.

UAAs exhibit significant value in multiple fields. They can optimize the pharmacokinetic properties of peptide drugs and peptidomimetics, modify enzyme functions and endow them with new biological activities, thereby overcoming the limitations of traditional peptide drugs and expanding the chemical space . Meanwhile, UAAs can serve as molecular probes to analyze protein-protein interactions and investigate the regulatory mechanisms of protein functions.

MCE has compiled a UAAs Fragment Library comprising nearly a thousand unnatural amino acid fragments with extensive coverage of chemical space and enhanced structural diversity. This compound library can be widely applied in peptide synthesis, drug design, and protein engineering.

Amino acids, as one of the most fundamental organic compounds in living organisms, serve not only as the basic building blocks of proteins but also but also undertake the functions of energy supply, neurotransmitter synthesis, and maintenance of internal environment stability.Amino acid metabolic enzymes are a class of enzymes involved in the metabolic processes of amino acids, catalyzing their synthesis, breakdown, transformation, and interactions with other metabolic pathways. Abnormalities in amino acid metabolic enzymes can lead to various metabolic diseases, such as phenylketonuria and hyperammonemia, etc. Therefore, actively exploring and regulating the processes of amino acid metabolism is crucial for the development of drugs related to these diseases.

MCE designs a unique collection of 338 small molecules target amino acid metabolizing enzymes, which is an important tool for studying studying amino acid metabolism processes or metabolism-related drug development.

Unlike the 20 natural amino acids commonly found within living organisms, non-natural amino acids are synthesized through chemical or biosynthetic methods, thereby being endowed with unique chemical properties or biological activities. In drug development, these amino acids can be utilized to design novel pharmaceutical molecules that may exhibit superior pharmacological characteristics, such as increased selectivity, improved pharmacokinetic profiles, or reduced toxicity. In biomedical research, uon-natural amino acids can act as biological markers or probes for investigating biological processes like cell signaling, protein conformation, and protein-protein interactions. In addition, non-natural amino acids can also be used in the field of agriculture to develop new pesticides, plant growth regulators and so on.

The transforming growth factor beta (TGF-β) signaling pathway is involved in many cellular processes in both the adult organism and the developing embryo including cell growth, cell differentiation, apoptosis, cellular homeostasis and other cellular functions. The TGF-β superfamily comprises TGF-βs, bone morphogenetic proteins (BMPs), activins and related proteins. Signaling begins with the binding of a TGF beta superfamily ligand to a TGF beta type II receptor. The type II receptor is a serine/threonine receptor kinase, which catalyzes the phosphorylation of the Type I receptor. The type I receptor then phosphorylates receptor-regulated SMADs (R-SMADs) which can now bind the coSMAD (e.g. SMAD4). R-SMAD/coSMAD complexes accumulate in the nucleus where they act as transcription factors and participate in the regulation of target gene expression. Deregulation of TGF-β signaling contributes to developmental defects and human diseases, including cancers, some bone diseases, chronic kidney disease, etc.

MCE designs a unique collection of 428 TGF-beta/Smad signaling pathway compounds. TGF-beta/Smad Compound Library acts as a useful tool for TGF-beta/Smad-related drug screening and disease research.

The majority of hypertensive patients have primary (or essential) hypertension, that is, hypertension in which secondary causes are not present. Management aims to control arterial pressure, prevent end-organ damage (cerebrovascular, cardiovascular, and renal), and reduce the risk of premature death.

Antihypertensive drugs may be divided into two broad groups, the first group being those which directly or indirectly block the renin–angiotensin system (RAS), for example, ACEIs, angiotensin receptor antagonists (ARAs), direct renin inhibitors (DRIs), and to a lesser extent β-blockers. The second group of drugs works by increasing water and sodium excretion, thereby reducing intravascular volume, or by causing vasodilatation through non-RAS pathways, for example, diuretics and calcium channel blockers (CCBs).

MCE offers a unique collection of 900 compounds with identified and potential antihypertensive activity. MCE Antihypertensive Compound Library is critical for antihypertensive drug discovery and development.

Peptides are a group of biologically active substances that are involved in various cellular functions of organisms. Peptides are often used in functional analysis, vaccine research and especially in the field of drug research and development. At present, more than 80 peptide drugs have reached the market for a wide range of diseases, including diabetes, cancer, osteoporosis, multiple sclerosis, HIV infection and chronic pain.

MedChemExpress (MCE) offers a comprehensive collection of 2,537 peptides, including bioactive peptides, amino acid derivatives, and blocking peptides. MCE Peptide Library can be used for peptide library screening, peptide drug discovery, vaccine development, target verification, structural activity research, etc.

Stem cells, which are found in all multi-cellular organisms, can divide and differentiate into diverse special cell types and can self-renew to produce more stem cells. To be useful in therapy, stem cells must be converted into desired cell types as necessary which is called induced differentiation or directed differentiation. Understanding and using signaling pathways for differentiation is an important method in successful regenerative medicine. Small molecules or growth factors induce the conversion of stem cells into appropriate progenitor cells, which will later give rise to the desired cell type. There is a variety of signal molecules and molecular families that may affect the establishment of germ layers in vivo, such as fibroblast growth factors (FGFs); the wnt family or superfamily of transforming growth factors β (TGFβ) and bone morphogenetic proteins (BMP). Unfortunately, for now, a high cost of recombinant factors is likely to limit their use on a larger scale in medicine. The more promising technique focuses on the use of small molecules. These small molecules can be used for either activating or deactivating specific signaling pathways. They enhance reprogramming efficiency by creating cells that are compatible with the desired type of tissue. It is a cheaper and non-immunogenic method.

MCE Differentiation Inducing Compound Library contains a unique collection of 2,439 compounds that act on signaling pathways for differentiation. These compounds are potential stimulators for induced differentiation. This library is a useful tool for researching directed differentiation and regenerative medicine.

Metabolism is the set of life-sustaining chemical reactions in organisms that maintain cell homeostasis. Metabolic pathways are enzyme-mediated biochemical reactions that lead to biosynthesis (anabolism) or breakdown (catabolism) of molecules including glucose metabolism, lipid metabolism and amino acid or protein metabolism within a cell or tissue. As catalysts, enzymes are crucial to metabolism as they allow a reaction to proceed more rapidly and tregulate the rate of a metabolic reaction. Due to the importance of metabolic balance in the organism, the abnormal function of metabolic enzymes often leads to the occurrence of a variety of metabolic diseases, such as diabetes, obesity, cardiovascular disease, etc.

MCE designs a unique collection of 4,232 metabolic enzymes related small molecules, which is an important tool for studying the metabolic activities of organisms and developing drugs for metabolic diseases.

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.

Mutations in oncogenes and tumor suppressor genes can modify multiple signaling pathways and in turn cell metabolism, which facilitates tumorigenesis. The paramount hallmark of tumor metabolism is “aerobic glycolysis” or the Warburg effect, coined by Otto Warburg in 1926, in which cancer cells produce most of energy from glycolysis pathway regardless of whether in aerobic or anaerobic condition. Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside. The increased uptake of glucose is facilitated by the overexpression of several isoforms of membrane glucose transporters (GLUTs). Likewise, the metabolic pathways of glutamine, amino acid and fat metabolism are also altered. Recent trends in anti-cancer drug discovery suggests that targeting the altered metabolic pathways of cancer cells result in energy crisis inside the cancer cells and can selectively inhibit cancer cell proliferation by delaying or suppressing tumor growth.

MCE provides a unique collection of 3,626 compounds which cover various tumor metabolism-related signaling pathways. These compounds can be used for anti-cancer metabolism targets identification, validation as well anti-cancer 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 2,445 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.

Cell proliferation, the increase in cell numbers resulting from cell division, is a complex and tightly regulated process. Cell proliferation is regulated by coordinated entry into the cell cycle, and changes in proliferation are closely linked to disease development. Evolutionary dynamics links tumor growth and progression with cell proliferation, cell death, and mutation rates. In addition, cell proliferation is central to degenerative diseases, the development of which is often accompanied by accelerated multiplication of cancer cells. Therefore, assays of cell proliferation levels are frequently used for laboratory research purposes and increasingly for clinical assessment of tumor aggressiveness and potentially to guide care. It has been shown that multiple key targets are collectively involved in regulating the process of cell proliferation, such as CDK, E2F, pRB, β-Catenin, and others.

MCE collects 3,458 compounds that target and regulate key targets of cell proliferation, which can be used in studies of cell proliferation mechanisms and drug discovery.

Neuronal Signaling is involved in the regulation of the mechanisms of the central nervous system (CNS) such as its structure, function, genetics and physiology as well as how this can be applied to understand diseases of the nervous system. Every information processing system in the CNS is composed of neurons and glia, neurons have evolved unique capabilities for intracellular signaling (communication within the cell) and intercellular signaling (communication between cells). G protein-coupled receptors (GPCRs), including 5-HT receptor, histamine receptor, opioid receptor, etc. are the largest class of sensory proteins and are important therapeutic targets in Neuronal Signaling. Besides, Notch signaling, such as β- and γ-secretase, also plays multiple roles in the development of the CNS including regulating neural stem cell (NSC) proliferation, survival, self-renewal and differentiation. GPCR dysfunction caused by receptor mutations and environmental challenges contributes to many neurological diseases. Notch signaling in neurons, glia, and NSCs is also involved in pathological changes that occur in disorders such as stroke, Alzheimer's disease and CNS tumors. Thus, targeting Neuronal Signaling, such as notch signaling and GPCRs, can be used as therapeutic interventions for several different CNS disorders.

MCE designs a unique collection of 3,854 Neuronal Signaling-related compounds that act as a useful tool for the research of neuronal regulation and neuronal diseases.

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.

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 2,101 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.

The most prominent mechanism of action of kinase inhibitors is their competition with ATP by binding to the hinge region of the kinase protein. Once the kinase is blocked by an inhibitor, it loses the ability to transfer phosphate groups from ATP to other molecules, resulting in the loss of kinase activity.

The hinge-binding region of kinase inhibitors mimics the interaction pattern between the ATP nucleobase and the kinase. MCE extracted thousands of kinase inhibitors from the ChEMBL database and isolated their molecular fragments. In certain cases, the amino and amide groups on the molecular fragments are crucial for binding in the hinge region. Therefore, we enhanced the diversity of the collected results by adding these two groups to unoccupied positions on the ring system. Subsequently, the fragments were assessed for their hinge region binding ability via docking at distinct kinases, we also applied pharmacophore constraints to ensure interactions with key amino acids in the kinase hinge region, ultimately obtaining kinase-related molecular fragments.

MCE provides over 12,410 kinase fragment molecules that meet the above requirements and are available off the shelf, serving as an effective tool for screening and developing drugs targeting kinases.

Neurodegenerative diseases are incurable and life-threatening conditions that result in progressive degeneration and/or death of nerve cells. Some common neurodegenerative diseases include Alzheimer’s Disease (AD), Parkinson’s Disease (PD), Motor Neuron Disease (MND), Huntington’s Disease (HD), Spino-Cerebellar Ataxia (SCA), Spinal Muscular Atrophy (SMA), and Amyotrophic Lateral Sclerosis (ALS). Because the pathophysiology of neurodegenerative disorders is generally poorly understood, it is difficult to identify promising molecular targets and validate them. At the same time, about 85% of the drugs fail in clinical trials. Therefore, validating new targets and discovering new drugs to mitigate neurodegenerative disorders is need of the hour.

MCE offers a unique collection of 3,605 compounds with anti-Neurodegenerative Diseases activities or targeting the unique targets of neurodegenerative diseases. MCE Neurodegenerative Disease-related Compound Library is a useful tool for exploring the mechanism of neurodegenerative diseases and discovering new drugs for neurodegenerative diseases.

Cyclic peptide library have advantages such as high affinity, high selectivity, and suitability for targeting protein–protein interactions. Through DEL synthesis technology, the library size can achieve hundreds of millions. DEL cyclic peptide library have advantages like low cost andhigh screeing efficiency, making them valuable for discovering lead compounds against challenging drug targets.

This cyclic peptide library is constructed with unnatural amino acids as building block, synthesized through DNA-compatible chemical reactions. Each cyclic peptide consist of six amino acids and constrained conformations such as side-chain cross-linking, disulfide bonds, and macrocyclization. These cyclic peptides exhibit significantly improved stability and druggability compared with linear peptides, filling the gap between small molecules and macromolecular biologics. Each cyclic peptide is uniquely conjugated to a DNA barcode sequence for molecular identification and sequencing decoding.

MCE’s cyclic peptide library has8 independent sub-libraries, with a total molecular diversity of 1.2 billion. It is constructed via multi-round combinatorial assembly of building blocks and diverse cyclization strategies, facilitating the discovery of cyclic peptide leads for undruggable targets.

The developmental proteins Hedgehog, Notch and Wnt are key regulators of cell fate, proliferation, migration and differentiation in several tissues. Their related signaling pathways are frequently activated in tumors, and particularly in the rare subpopulation of cancer stem cells. The Wnt signaling pathway is a conserved pathway in animals. Deregulated Wnt signaling has catastrophic consequences for the developing embryo and it is now well appreciated that defective Wnt signaling is a causative factor for a number of pleiotropic human pathologies, including cancer. Hedgehog signaling pathway is linked to tumorigenesis and is aberrantly activated in a variety of cancers. The Notch signaling pathway is a highly conserved cell signaling system present in most animals. It plays an important role in cell-cell communication, and further regulates embryonic development.

MCE designs a unique collection of 616 Wnt/Hedgehog/Notch signaling pathway-related small molecules. Wnt/Hedgehog/Notch Compound Library serves as a useful tool for stem cell research and anti-cancer drug screening.

Post-translational modifications (PTMs) refer to chemical modifications that occur on amino acid residues of proteins after translation, involving the addition or removal of specific functional groups. These modifications regulate protein activity, localization, folding, and interactions with other biomolecules. By influencing protein function, PTMs play a crucial role in various pathophysiological processes. Common types of PTMs include protein phosphorylation, methylation, acetylation, ubiquitination, glycosylation, and more.

MCE offers 3,704 PTM-targeting compounds, which can be used for drug screening in cancer, neurodegenerative diseases, metabolic disorders, etc.

Neurotransmitters are chemical messengers that allows a neuron's electrical signal to pass to a postsynaptic neuron or effect target. Neurotransmitters include amino acids, monoamines, and peptides, while other neurotransmitters are composed of metabolites such as nitric oxide and carbon monoxide. The function of neurotransmitters is closely related to the disease of life, helping to regulate the body's heartbeat, blood pressure, breathing, sleep, aging and muscle activity. Therefore, research based on neurotransmitters can help to increase human understanding of diseases.

MCE collects and organizes 58 neurotransmitters and is a tool library for drug screening and mechanism research.

Glutamine is an important metabolic fuel that helps rapidly proliferating cells meet the increased demand for ATP, biosynthetic precursors, and reducing agents. Glutamine Metabolism pathway involves the initial deamination of glutamine by glutaminase(GLS), yielding glutamate and ammonia. Glutamate is converted to the TCA cycle intermediate α-ketoglutarate (α-KG) by either glutamate dehydrogenase (GDH) or by the alanine or aspartate transaminases (TAs), to produce both ATP and anabolic carbons for the synthesis of amino acids, nucleotides and lipids. During periods of hypoxia or mitochondrial dysfunction, α-KG can be converted to citrate in a reductive carboxylation reaction catalyzed by IDH2. The newly formed citrate exits the mitochondria where it is used to synthesize fatty acids and amino acids and produce the reducing agent, NADPH.

Cancer cells display an altered metabolic circuitry that is directly regulated by oncogenic mutations and loss of tumor suppressors. Mounting evidence indicates that altered glutamine metabolism in cancer cells has critical roles in supporting macromolecule biosynthesis, regulating signaling pathways, and maintaining redox homeostasis, all of which contribute to cancer cell proliferation and survival. Thus, intervention in glutamine metabolic processes could provide novel approaches to improve cancer treatment.

MCE owns a unique collection of 1,730 compounds targeting the mainly proteins and enzymes involved in glutamine metabolism pathway. Glutamine Metabolism compound library is a useful tool for intervention in glutamine metabolic processes.

Dipeptide compounds have attracted extensive attention in drug discovery and life science research due to their simple structures, ease of modification, and favorable biocompatibility. As small peptides composed of two amino acids, dipeptides exhibit diverse biological activities, including anti-inflammatory, antioxidant, antimicrobial, anticancer, and immunomodulatory effects, showing significant application potential in metabolic disorders, neurological diseases, and cancer research. Compared with traditional small molecules, dipeptide compounds possess favorable target-binding properties and high structural plasticity, making them valuable tools for drug screening and mechanism studies.

The MCE Dipeptide Compound Library contains 80 dipeptide compounds and can be applied to peptide drug discovery and development.

DEL technology enables the simultaneous screening of millions or billions of compounds in a single tube by covalently linking each small molecule with a unique DNA sequence. Traditional DEL screening primarily focuses on identifying non-covalent binding molecules, where interactions with the target are reversible. In contrast, DNA‑encoded covalent library is an ultra‑high‑throughput screening library developed on the basis of conventional DNA‑encoded library technology. It incorporates controllable electrophilic covalent warheads capable of forming irreversible covalent bonds with amino acid residues at the active sites of target proteins, including Cys, Lys, Ser, Tyr, and others. This covalent binding enhances binding affinity, prolongs residence time at the target site, and has the potential to overcome challenges associated with traditional non-covalent inhibitors, such as drug resistance or off-target effects.

Each compound in the library contains both a binding domain and an electrophilic warhead. It first recognizes and binds to the target through non covalent interactions, and then forms a stable covalent bond with key amino acid residues to achieve irreversible inhibition. This library is specifically designed for the discovery of potent, long lasting, and highly selective covalent inhibitors, particularly for undruggable targets such as kinases, GPCRs, proteases, and mutant oncoproteins. Each molecule is uniquely labeled with a DNA barcode for molecular identification and sequencing decoding.

This library is an advanced and highly diverse collection, consists of 35 independent sub-libraries with a total scaleof 14 million compounds, It incorporates over 14 experimentally validated covalent warheads capable of targeting cysteine, lysine, arginine, aspartic acid and glutamic acid. This library is constructed with diverse drug like core scaffolds and integrated controllable covalent warheads, it features structural diversity, reaction spec

A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products. Proteases play important roles in regulating multiple biological processes in all living organisms, such as regulating the fate, localization, and activity of many proteins, modulating protein-protein interactions, creating new bioactive molecules, contributing to the processing of cellular information, and generating, transducing, and amplifying molecular signals.

Proteases are important targets in drug discovery. Some protease inhibitors are often used as anti-virus drugs and anti-cancer drugs. MCE offers a unique collection of 932 protease inhibitors. MCE Protease Inhibitor Library is critical for drug discovery and development.

Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, arises as adenocarcinoma from glandular epithelial cells of the large intestine comprised of the colon and rectum. The majority of cases of CRC are sporadic and result from risk factors, such as a sedentary lifestyle, obesity, processed diets, alcohol consumption and smoking. CRC is also a common preventable cancer.

Studies showed several cellular signaling pathways dysregulated in CRC, leading to the onset of malignant phenotypes. Therefore, it is necessary to analyze the signaling pathways involved in the occurrence and development of colorectal cancer to study the progression and drug treatment of colorectal cancer. Among them, Wnt/β-catenin, p53, TGF-β/SMAD, NF-κB, Notch, VEGF and other target genes and signaling pathways are the focus of research. MCE offers a unique collection of 2,522 compounds with identified and potential anti-colorectal cancer activity. MCE anti-colorectal cancer compound library is a useful tool for anti-colorectal cancer drugs screening and other related research.

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.

Exosomes are small membrane vesicles of endocytic origin that are secreted by most cells in culture. Exosomes contain nucleic acids, proteins, lipids, amino acids, and metabolites, etc. Their diverse constituents can reflect their cell of origin. Exosomes are associated with immune responses, viral pathogenicity, pregnancy, cardiovascular diseases, central nervous system-related diseases, and cancer progression. Proteins, metabolites, and nucleic acids delivered by exosomes into recipient cells effectively alter their biological response. Such exosome-mediated responses can be disease promoting or restraining.

The biology of exosomes in disease is still emerging, and the number of studies addressing their utility in the diagnosis and treatment of various pathologies has increased substantially. MCE supplies a unique collection of 53 compounds with the activity of inhibiting or stimulating exsomes secretion/biosynthesis. MCE Exosomes Compound Library is a useful tool for exsomes research.

Human metabolism is an integral part of cellular function that reflects individual differences in health, disease, diet, and lifestyle. Many health conditions such as obesity, diabetes, hypertension, heart disease, and cancer are associated with abnormal metabolic states. In the pathological state of the human body, metabolic pathways are significantly altered, resulting in aberrant levels of intermediates or end-products that can be viewed as potential diagnostic biomarkers or even therapeutic targets. Therefore, detection, identification and quantification of human metabolites are very important for drug metabolism research in drug development.

MCE offers a unique collection of 6,744 human metabolites, including endogenous metabolites and exogenous metabolites, covering multiple structure types, such as lipids, amino acids, nucleic acids, carbohydrates, organic acids, biogenic amines, vitamins,. MCE Human Metabolites Library is a helpful tool for studying the relationship between diseases and metabolism.

Animal drug (also veterinary drug) refers to a drug intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in animals. Animal Drugs @ FDA is a searchable online database that includes most FDA-approved and conditionally approved animal drugs. The major classes of veterinary drugs include antibiotics, anthelmintics, coccidiostats, nonsteroidal anti-inflammatory drugs, sedatives, corticosteroids, beta-agonists, and anabolic hormones.

MCE has collected 167 FDA-approved veterinary drug compounds for use in scientific research.

Dietary supplement, also known as nutritional supplement or food supplement, include dietary components such as vitamins, minerals, and amino acids. The unique value of dietary supplement is particularly significant in the post-pandemic era. Compared to traditional medication, dietary supplement is often more readily accepted by the public due to their higher safety profile and the natural origin. By orally supplementing essential nutrients and bioactive substances, dietary supplement can help to enhance the body's health level and reduce the risk of diseases. For certain chronic conditions, proper dietary supplement can also serve as a powerful adjunct to conventional medical treatment, enhancing the effectiveness of medication.

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. Currently, cysteine is the most common covalent amino acid residue in a variety of covalent drugs, and various warheads have been developed that can react with cysteine, providing the key building blocks for covalent drugs to form covalent bonds.

To meet the development needs of covalent inhibitors targeting cysteine, MCE has designed a unique collection of 5,137 compounds with different covalent warheads that target cysteine. The MCE Cysteine Targeted Covalent Library is designed using the following covalent warheads: Acrylamides, Propiolic acid ester, Dimethylamine functionalized acrylamides, Chloroacetamides, Acrylonitrile, 2-Cyanoacrylamide, Aziridine, Haloacetamide, etc.

Heterocyclic compounds are cyclic organic compounds which contain at least one hetero atom, the most common heteroatoms are nitrogen, oxygen ,and sulfur. Heterocycles are common in biology, featuring a wide range of structures from enzyme co-factors to amino acids and proteins. On the one hand, heterocycles are common structural units in approved drugs and in medicinal chemistry targets in the drug discovery process. In addition, heterocycles have been found as a key structure in medical chemistry and also they are frequently found in large percent of biomolecules such as vitamins, natural products ,and biologically active compounds including antifungal, anti-inflammatory, antibacterial, antioxidant, antiallergic, anti-HIV, antidiabetic, anticancer activity.

MCE offers a unique collection of 6,508 heterocyclic compounds which can be used for drug discovery for high throughput screening (HTS) and high content screening (HCS). MCE heterocyclic compound library is critical for drug discovery and development.

A histone modification, a covalent post-translational modification (PTM) to histone proteins, includes methylation, phosphorylation, acetylation, ubiquitylation, and sumoylation, etc. In general, histone modifications are catalyzed by specific enzymes that act predominantly at the histone N-terminal tails involving amino acids such as lysine or arginine, as well as serine, threonine, tyrosine, etc. The PTMs made to histones can impact gene expression by altering chromatin structure or recruiting histone modifiers. Histone modifications act in diverse biological processes such as transcriptional activation/inactivation, chromosome packaging, and DNA damage/repair. Deregulation of histone modification contributes to many diseases, including cancer and autoimmune diseases.

MCE owns a unique collection of 919 bioactive compounds targeting Epigenetic Reader Domain, HDAC, Histone Acetyltransferase, Histone Demethylase, Histone Methyltransferase, Sirtuin, etc. Histone Modification Research Compound Library is a useful tool for histone modification research and drug screening.

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. Currently, cysteine is the most common covalent amino acid residue in a variety of covalent drugs, and various warheads have been developed that can react with cysteine, providing the key building blocks for covalent drugs to form covalent bonds.

To meet the development needs of covalent inhibitors targeting cysteine, MCE has designed a unique collection of 3,622 fragments with different covalent warheads that target cysteine. The MCE Cysteine Targeted Covalent Fragment Library is designed using the following covalent warheads: Acrylamides, Propiolic acid ester, Dimethylamine functionalized acrylamides, Chloroacetamides, Acrylonitrile, 2-Cyanoacrylamide, Aziridine, Haloacetamide, etc. All fragments are pre-filtered with the Rule of Three restrictions which can be used for fragment-based covalent drug development.

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.

Peptides, composed of amino acids, serve as crucial building blocks for proteins and have gained significant attention in drug development over the past decade. The advancements in production, modification, and analytical technologies have led to a surge in the potential applications of peptides in medicine. Peptides offer a number of advantages over small molecule drugs, including: greater target specificity and efficacy, more predictable metabolic profiles, easier delivery to where they are needed in the body, and fewer side effects. Peptides are increasingly appearing in all branches of medicine as components of innovative drugs, imaging agents, diagnostic agents, and other complex drugs such as peptide-drug conjugates. To date, more than 80 peptide drugs have been approved to treat a variety of diseases, including microbial infections, obesity, anti-diabetes, and cancer, as well as to develop cell targeting platforms and improve cell penetration properties.

MCE designs a unique collection of 832 peptide compounds. HY-L105S is a peptide compound library that can be provided with solution form based on HY-L105, and can be applied to peptides-based drug development.

Bile acids are a class of amphiphilic molecules derived from the metabolic breakdown of cholesterol, primarily synthesized in the liver, and play a crucial role in the intestines. Based on their structural characteristics, bile acids are mainly divided into two categories: free bile acids (including Cholic acid, Deoxycholic acid, Chenodeoxycholic acid) and conjugated bile acids (including Glycocholic acid, Glycochenodeoxycholic acid, Taurocholic acid, etc.). Bile acids play a significant role in the pathophysiological research of liver and gastrointestinal diseases and are closely associated with the occurrence of metabolic diseases such as obesity, type II diabetes, non-alcoholic fatty liver disease, and atherosclerosis. Bile acids maintain metabolic balance within the body by regulating sugar metabolism, lipid metabolism, and amino acid metabolism, and they influence the activity of metabolism-related enzymes and transporters. In addition, Bile acids can also be used to construct a bile acid metabolism research platform, which helps to delve into the metabolic pathways and dynamic changes of bile acids in living organisms and aids in identifying new biomarkers for certain diseases.

MCE included 61 bile acids, including Cholic acid, Deoxycholic acid, Glycocholic acid, etc., which are effective tools for the study of liver and gallbladder diseases.

Fatty acids (FAs) are the main components of lipids. The synthesis of fatty acids mainly involves the Triglyceride (TG) cycle and De Novo Lipogenesis (DNL). Fatty acids which exist widely in organisms are components of cell membranes and play an indispensable role in cell signaling. In addition, FFAs can be taken up from circulating plasma by all mitochondria-containing cells, and they are metabolized by β-oxidation and the citric acid cycle to release large amounts of energy in the form of ATP. Abnormal fatty acid metabolism is associated with the occurrence and development of cardiovascular diseases, diabetes, fatty liver, hyperthyroidism, and other diseases.

MCE offers a unique collection of fatty acid compounds. Fatty Acids Compound Library is an important tool for the study of energy metabolism and drug development of metabolism-related diseases.

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.

Boronic acid and boronic ester represent a relatively novel and promising chemical structure in drug design. Boronic acid exists in an sp²-hybridized state, possessing an empty p-orbital that can act as a Lewis acid to accept lone pairs from heteroatoms (O, N, or S). This Lewis acidity enables it to form reversible covalent bonds with amino acid residues such as lysine, serine, threonine, and histidine. Currently, five FDA-approved drugs containing boronic acid or boronic ester predominantly involve such covalent binding mechanisms in their interactions with target proteins. Furthermore, boronic acid can serve as a bioisostere for carboxylic acids, phosphates, and phenolic groups, utilized to improve pharmacokinetic properties and enhance drug efficacy.

To date, five boron-containing drugs have been approved by the FDA. The unique properties of boronic acids and boronic esters confer significant potential in drug design, with applications spanning cancer therapy (e.g., multiple myeloma), anti-infectives (e.g., fungal infections, tuberculosis), anti-inflammatory treatments (e.g., atopic dermatitis), antibacterial agents (e.g., carbapenem-resistant bacterial infections), and Reactive Oxygen Species (ROS)-responsive prodrugs, among others. The MCE Boronic Acid/Boronic Ester Fragment Library, which contains 1,488 compounds, serves as a valuable tool for the development of boron-containing drugs.

Protein protein interactions (PPI) have pivotal roles in life processes. The studies showed that aberrant PPI are associated with various diseases. However, the design of modulators targeting PPI still faces tremendous challenges, such the difficult PPI interfaces for the drug design, lack of ligands reference, lack of guidance rules for the PPI modulators development and high-resolution PPI proteins structures.

The PPI Library comprises molecules of various sizes, frameworks, and shapes ranging from fragment-like entities to macrocyclic derivatives designed as secondary structure mimetics or as epitope mimetics. The designs cover β-turn / loop mimetics and α-helix mimetics. Since helices present at the interface in 62% of all protein-protein interactions. This library focused on designs including mimics with the substitution geometry of an a-helices, as well as designs that mimic the location of “hot-spot” side chains in helix-mediated PPIs.

Autoimmune disease is a pathological disease characterized by inflammatory disorders targeting autoantigens. The routine treatment of autoimmune diseases suppresses general immune function to regulate uncontrolled inflammation. The current targeted immunotherapy suppresses the main pro-inflammatory signaling pathways by blocking inflammatory cytokines, cell surface molecules, and intracellular kinases. As key participants in innate immunity, macrophages and dendritic cells (DCs) are crucial for Ag presentation and pro-inflammatory cytokine production, such as TNF and IL-1 β、 IL-6, IL-23, B cell activating factor (BAFF), and the proliferation-inducing ligand (APRIL, also known as TNFSF13A).

MCE designs a unique collection of 966 autoimmune disease-related compounds, covering multiple targets and subtypes, such as TNF Receptor, IFNAR, JAK, Btk, TLR, IL-6, IL-17, IL-23, etc. It is a useful tool for screening autoimmune disease drugs.

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 2,684 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.

In the research of covalent inhibitors targeting serine and threonine, scientists have found that the nucleophilicity of these hydroxyl groups is significantly enhanced due to the influence of their surrounding environment. This results in higher activity during catalytic reactions. Aspirin, which targets the non-catalytic domain serine (Ser529 in human COX1) of cyclooxygenase, exerts its anti-inflammatory effect through covalent binding. β-lactam antibiotics, which targets the catalytic domain serine of penicillin-binding proteins, interferes with bacterial cell wall synthesis.

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 3,300 fragment molecules which can target serine and threonine residues and can be used for fragment-based covalent drug discovery.

Oxygen homeostasis regulation is the most fundamental cellular process for adjusting physiological oxygen variations, and its irregularity leads to various human diseases, including cancer. Hypoxia is closely associated with cancer development, and hypoxia/oxygen-sensing signaling plays critical roles in the modulation of cancer progression.

Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that functions as a master regulator of oxygen homeostasis. A variety of HF-1 target genes have been identified thus far which encode proteins that play key roles in critical developmental and physiological processes including angiogenesis/vascular remodeling, erythropoiesis, glucose transport, glycolysis, iron transport, and cell proliferation/survival.

HIF-1 is a heterodimeric transcription factor consisting of a constitutively expressed β-subunit and an oxygen-regulated α-subunit. The unique feature of HIF-1 is the regulation of HIF-1α expression and activity based upon the cellular O₂ concentration. Under normoxic conditions, hydroxylation of HIF-1α on these different proline residues is essential for HIF proteolytic degradation by promoting interaction with the von Hippel-Lindau tumor-suppressor protein (pVHL) through hydrogen bonding to the hydroxyproline-binding pocket in the pVHL β-domain. As oxygen levels decrease, hydroxylation of HIF decreases; HIF-1α then no longer binds pVHL, and becomes stabilized, allowing more of the protein to translocate to the cell’s nucleus, where it acts as a transcription factor, upregulating (often within minutes) the production of proteins that stimulate blood perfusion in tissues and thus tissue oxygenation.

MCE offers a unique collection of 4,097 oxygen sensing related compounds targeting HIF/HIF Prolyl-Hydroxylase, MAPK/ERK, PI3K/AKT signaling pathways, etc. MCE Oxygen Sensing Compound Library is a useful tool to study hypoxia, oxidative stress and discover new anti-cancer drugs.

L-glutamine is an important amino acid supplement commonly added to mammalian cell culture media. L-glutamine serves as an auxiliary energy source, especially when cells are rapidly dividing. L-glutamine is also important in the production of purine and pyrimidine nucleotides, amino sugars, glutathione, L-glutamate, other amino acids, and plays a role in protein synthesis and glucose production.

MCE HOLO Human Interleukin-1β (IL-1β) Detection Kit is a homogeneous luminescence-based assay used for the quantitative detection of human IL-1β concentrations in biological samples such as buffer solutions, cell culture supernatants, or serum.

MCE HOLO Human Tumor Necrosis Factor-β (TNF-β) Detection Kit is a homogeneous luminescence-based assay used for the quantitative detection of human TNF-β concentrations in biological samples such as buffer solutions, cell culture supernatants, or serum.

Protein Deglycosylation Kit (for N-linked & Complex O-linked Glycans) includes the enzymes and reagents reuired for the removal of all N-linked and some complex O-linked glycans. The enzyme reagent in this kit is a mixture of five glycosidases, namely PNGase F, O-Glycosidase, α2-3,6,8,9 Neuraminidase, β1-4 Galactosidase, and β-N-Acetylhexosaminidase. All enzymes in this kit are recombinant enzymes expressed in Escherichia coli BL21 and subsequently purified. The molecular weights of these enzymes are as follows: PNGase F is 36 kDa, O-Glycosidase is 14 kDa,α2-3,6,8,9 Neuraminidase is 66 kDa, β1-4 Galactosidase is 94 kDa, and β-N-Acetylhexosaminidase is 55 kDa.

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.

O-Glycosidase is highly specific and can release Galβ1-3GalNAc from serine, threonine residues or as part of a glycopeptide or glycoprotein. Applied to glycoprotein biosynthesis analysis, O-glycan bioactive protein O-glycosylation detection and binding site analysis.

MCE Cell Senescence β-Galactosidase Staining Kit can be used to evaluate the senescence of cells or tissues.

MCE Amino magnetic beads (200 nm，10 mg/mL) can easily and efficiently combine with a variety of biological ligand in high loads, such as proteins, peptides, oligonucleotides, drug molecules, etc. It can be used as a good basic material for subsequent processing, adsorption, chemical modification and other follow-up processing.

Minimum Essential Medium (MEM), also known as Minimal Essential Medium, was developed by Harry Eagle based on Eagle’s Basal Medium (BME). It is a basic cell culture medium with a simple formulation and broad applicability, and is one of the most commonly used media in animal cell culture. MEM contains only 12 essential amino acids, L-glutamine, and 8 vitamins. It is primarily used for the culture of adherent cells. With appropriate formulation modifications, it can also be used for other types of cell culture.

MCE Human iPSC/ESC Cardiomyocyte Induction Differentiation Kit is based on the classical GiWi system. By precisely modulating the Wnt/β-catenin signaling pathway in a temporally controlled manner (sequential activation and inhibition), the kit enables highly efficient directed differentiation of human pluripotent stem cells into cardiomyocytes. It is suitable for cardiac disease modeling, drug cardiotoxicity assessment, and mechanistic studies.

MCE Human iPSC/ESC Cortical Brain Organoid Induction Differentiation Kit is a standardized culture system specifically designed to recapitulate the developmental processes and functional features of the human cerebral cortex through forebrain ventralization-based signaling regulation. By sequentially activating the Wnt/β-catenin pathway and gradually inhibiting BMP/Smad signaling, this system efficiently drives human pluripotent stem cells (PSC) to differentiate into high-purity glutamatergic neurons (VGLUT1/2⁺ > 85%), while simultaneously promoting the formation of Pax6⁺/BLBP⁺ radial glial cells that establish a biomimetic ventricular-zone–like structure.