histamine H₄ receptor antagonists

Neurotransmitter (NT) receptors, also known as neuroreceptors, are a broadly diverse group of membrane proteins that bind neurotransmitters for neuronal signaling. There are two major types of neurotransmitter receptors: ionotropic and metabotropic. Ionotropic receptors are ligand-gated ion channels, meaning that the receptor protein includes both a neurotransmitter binding site and an ion channel. The binding of a neurotransmitter molecule (the ligand) to the binding site induces a conformational change in the receptor structure, which opens, or gates, the ion channel. The term “metabotropic receptors” is typically used to refer to transmembrane G-protein-coupled receptors. Metabotropic receptors trigger second messenger-mediated effects within cells after neurotransmitter binding.

In some neurological diseases, the neurotransmitter receptor itself appears to be the target of the disease process. Many neuroactive drugs act by modifying neurotransmitter receptors. A better understanding of neurotransmitter receptor changes in disease may lead to improvements in therapy.

MCE designs a unique collection of 1806 compounds targeting a variety of neurotransmitter receptors. MCE Neurotransmitter Receptor Compound Library is a useful tool for neurological diseases drug discovery.

Membrane receptors, also known cell surface receptors or transmembrane receptors, are transmembrane proteins embedded into the plasma membrane which play an essential role in maintaining communication between the internal processes within the cell and various types of extracellular signals. They act in cell signaling by receiving (binding to) extracellular molecules, which are also called ligands. These extracellular molecules include hormones, cytokines, growth factors, neurotransmitters, lipophilic signaling molecules such as prostaglandins, and cell recognition molecules.

There are three kinds of membrane receptors: ion channel-linked receptors, enzyme-linked receptors and G-protein-linked receptors. They play important roles in keeping human normal physiologic processes. GPCRs and ion channels are important drug targets in drug discovery.

MCE provides a unique collection of 4674 compounds targeting a variety of membrane receptors. MCE Membrane reeptor-targeted Compound Library can be used for membrane receptor-focused screening and drug discovery.

Nuclear receptors (NR) are proteins found in cells that sense androgen and thyroid hormones and certain other molecules. They are ligand-activated transcription factors that participate in many aspects of human physiology and pathology, and regulate the expression of various important genes.

Nuclear receptors have become one of the main targets in the development of new drug strategies, providing a unique type of receptors for studying a variety of human diseases, such as breast cancers, skin disorders and diabetes. 13% of U.S. Food and Drug Administration (FDA) approved drugs target nuclear receptors.

MCE supplies a unique collection of 668 nuclear receptor inhibitors and activators, all of which have the identified inhibitory or activated effect on nuclear receptor. MCE Nuclear Receptor Library is a useful tool for drugs research related to cancer, skin disease and diabetes.

GABA receptors are a class of receptors that respond to the neurotransmitter gamma-aminobutyric acid (GABA), the chief inhibitory neurotransmitter in the vertebrate central nervous system. There are two classes of GABA receptors: GABAA and GABAB. GABAA receptors are ligand-gated ion channels (also known as ionotropic receptors), whereas GABAB receptors are G protein-coupled receptors (also known asmetabotropic receptors). GABA receptors are significant drug targets in the treatment of neuropsychiatric disorders such as epilepsy, insomnia, and anxiety, as well as in anesthesia in surgical operations.

MCE offers a unique collection of 139 GABA receptors inhibitors and activators, which is an efficient tool for neuropsychiatric disorders drugs discovery.

Dopamine receptor (DAR), widely distributed in the brain, plays a key role in regulating motor function, motivation, driving force and cognition. The role of DA is mediated by D1-type (D1, D5) and D2-type receptors (D2S, D2L, D3, D4), which are distributed in presynaptic, postsynaptic and extrasynaptic, projection neurons and interneurons. Each receptor has a different function. D1 and D5 receptors couple with G stimulation sites and activate Adenylyl cyclase. The activation of Adenylyl cyclase leads to the production of the second messenger cAMP, which leads to the production of protein kinase A (PKA), which leads to further transcription in the nucleus. D2 to D4 receptors are coupled to G inhibitory sites to inhibit adenylyl cyclase and activate potassium Ion channel. These receptors utilize phosphorylation cascades or direct membrane interactions to affect the functions of voltage-gated and neurotransmitter-gated channels, cytoplasmic enzymes, and transcription factors. Dopamine receptor plays an important role in daily life.

MCE designs a unique collection of 199 small molecules related to dopamine receptor. It is a good tool for screening drugs from nervous system disease.

5-HT receptors, also called Serotonin receptors, are a group of G protein-coupled receptors (GPCRs) and ligand-gated ion channels (LGICs) found in the central and peripheral nervous systems. These receptors are now classified into seven families, 5-HT1–7, comprising a total of 14 structurally and pharmacologically distinct mammalian 5-HT receptor subtypes. The 5-HT receptors influence various biological and neurological processes such as aggression, anxiety, appetite, cognition, learning, memory, mood, nausea, sleep, andthermoregulation. The serotonin receptors are the target of a variety of pharmaceutical drugs, including many antidepressants, antipsychotics, anorectics, antiemetics, gastroprokinetic agents, antimigraine agents, hallucinogens, and entactogens.

MCE 5-HT Receptor Compound Library consists of 310 5-HT receptor inhibitors and activators, which can be used for neuropsychiatric disorders drugs discovery.

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 4971 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.

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 2572 Neuronal Signaling-related compounds that act as a useful tool for the research of neuronal regulation and neuronal diseases.

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 22464 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.

Calcium channel blockers (CCBs), also called calcium antagonists are compounds that slow the movement of calcium (Ca2+) through calcium channels into the cells of the heart and blood vessel walls. Calcium causes the heart and arteries to squeeze more strongly. By blocking calcium, calcium channel blockers allow blood vessels to relax and open. So calcium channel blockers are usually used to lower blood pressure, relieve chest pain (angina) and control an irregular heartbeat.

MCE supplies a unique collection of 150 calcium channel blockers and antagonists, all of which have the identified inhibitory effect on calcium channel. MCE Calcium Channel Blocker Library is a useful tool for discovery of antihypertensive drugs and cardiovascular disease research.

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 2255 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.

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 1068 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 endocrine system is a chemical messenger system comprising feedback loops of the hormones released by internal glands of an organism directly into the circulatory system, regulating distant target organs. Hormones are chemicals that serve to communicate between organs and tissues for physiological regulation and behavioral activities. Hormones affect distant cells by binding to specific receptor proteins in the target cell, resulting in a change in cell function.

The endocrine system is concerned with the integration of developmental events proliferation, growth, and differentiation, and the psychological or behavioral activities of metabolism, growth and development, tissue function, sleep, digestion, respiration, excretion, mood, stress, lactation, movement, reproduction, and sensory perception caused by hormones. Irregulated hormone release, inappropriate response to signaling or lack of a gland can lead to endocrine disease.

MCE offers a unique collection of 874 endocrinology related compounds targeting varieties of hormone receptors such as thyroid hormone receptor, TSH receptor, GNRH receptor, adrenergic receptor, etc. MCE Endocrinology Compound Library is a useful tool for the discovery of endocrinology drugs.

Chemokines, or chemotactic cytokines, are small cytokines or signaling proteins secreted by cells. They are a component of intercellular communication, controlling the directional movement of immune cells especially leukocytes, as well as other cell types, for instance, endothelial and epithelial cells, which are essential to maintain human health and the function of the immune system.

The biological effects of chemokines are achieved by binding to chemokine receptors, which are G protein-coupled receptors found on the surface of leukocytes. Some chemokine receptors are involved in directing tumor metastasis and over-expression by certain tumors. So inhibiting the interaction between chemokine and chemokine receptors on the surface of tumor cells may be a new possible therapeutic approach. Some chemokine receptors are coreceptors for HIV entry, and related inhibitors have been approved by the FDA to treat patients with HIV. Obviously, chemokines and chemokine receptors have become new targets for studying cancer, HIV, inflammation, and other diseases.

MCE supplies a unique collection of 149 chemokine or chemokine receptor inhibitors and activators, all of which have the identified inhibitory or activated effect on chemokine or chemokine receptors. MCE Chemokine Library is a useful tool for drug research related to cancer, AIDS, and wound therapy.

Sodium channels conduct sodium ions (Na+) through a cell's plasma membrane that are the source of excitatory currents for the nervous system and muscle. Na channels are classified according to the trigger that opens the channel for such ions, i.e. either a voltage-change (Voltage-gated, voltage-sensitive, or voltage-dependent sodium channel also called VGSCs or Nav channel) or a binding of a substance (a ligand) to the channel (ligand-gated sodium channels). Dysfunction in voltage-gated sodium channels correlates with neurological and cardiac diseases, including epilepsy, myopathies, pain and cardiac arrhythmias. Sodium channel blockers are used in the treatment of cardiac arrhythmia, pain and convulsion.

MCE offers a unique collection of 129 sodium channel blocker and antagonists, all of which have the identified inhibitory effect on sodium channels. MCE Sodium Channel Blocker Library can be used for neurological and cardiac diseases drug discovery and sodium channel research.

GPCRs are a large family of cell surface receptors that respond to a variety of external signals. Binding of a signaling molecule to a GPCR results in G protein activation, which in turn triggers the production of any number of second messengers. GPCRs play an important role in the human body, and increased understanding of these receptors has greatly affected modern medicine. In fact, researchers estimate that between one-third to one-half of all approved drugs act by binding to GPCRs. GPCRs are a large group of drug targets in drug discovery.

MCE provides a unique collection of 2316 small molecules targeting GPCRs that can be used in the screening for various GPCRs-related research and drug development projects.

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 226 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.

This library contains about 439,804 natural and synthetic screening compounds. The information in the database includes logP, H-bond donors, H-bond acceptors, rotable bonds.

Immunity refers to the ability of the body to resist the invasion of pathogenic microorganisms and resist a variety of diseases. Immunocompromised will inevitably lead to a series of diseases. Immunopotentiator are a class of compounds that enhance immune function and induce immune response. Immunopotentiator can activate the proliferation and differentiation of one or more kinds of immune active cells in the body, promote the secretion of lymphocytes, and then enhance the immune function of the body. Immunopotentiator are mainly used in the treatment of tumors, infectious diseases and immunodeficiency diseases. In addition, immunopotentiator are often used as adjuvants in combination with vaccine antigens to enhance the immunogenicity of vaccines.

MCE designs a unique collection of 82 compounds with definite or potential Immunopotentiating effect, mainly targeting the NOD-like Receptor (NLR), Toll-like Receptor (TLR), NF-κB, etc. It is an effective tool for development and research of anti-cancer, anti-infectious diseases and anti-immunodeficiency diseases compounds.

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 3165 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.

Protein tyrosine kinases (PTKs) are key signaling molecules and important drug targets. Two classes of PTKs are present in cells: the transmembrane receptor PTKs (RTKs) and the nonreceptor PTKs. The RTK family includes the receptors for insulin and for many growth factors, such as EGFR, FGFR, PDGFR, VEGFR, and NGFR. RTKs are transmembrane glycoproteins that are activated by the binding of their ligands, and they transduce the extracellular signal to the cytoplasm by phosphorylating tyrosine residues on the receptors themselves (autophosphorylation) and on downstream signaling proteins. Their principal functions of PTKs involve the regulation of multicellular aspects of the organism. Cell to cell signals concerning growth, differentiation, adhesion, motility, and death are frequently transmitted through tyrosine kinases. In humans, tyrosine kinases have been demonstrated to play significant roles in the development of many disease states, including diabetes and cancers.

MCE designs a unique collection of 1064 compounds that act as a useful tool for PTKs-related drug screening and disease 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. 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 4528 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.

Cytokines are a kind of low molecular soluble proteins synthesized and secreted by immunogen, mitogen or other factors. They have functions of regulating innate and adaptive immune responses, promoting hematopoiesis, stimulating cell activation, proliferation and differentiation. The process of releasing a large number of cytokines is also called “Cytokine storm”, which can cause damage to many tissues and organs in the body. Cytokine is involved in the pathogenesis of many human diseases, including cancer, diabetes, chronic inflammatory diseases and so on. Cytokine inhibitors are a class of essential compounds that act by directly inhibiting the synthesis and release of cytokine or blocking the binding of cytokine to their receptors. Cytokine inhibitors are important compounds for the study of tumor and autoimmune diseases.

MCE designs a unique collection of 827 cytokine inhibitors, mainly targeting the receptor interleukin (IL), colony-stimulating factor (CSF), interferon (IFN), tumor necrosis factor (TNF), growth factor (GF) and chemokine, which is an effective tool for development and research of anti-cancer, anti-chronic inflammatory diseases and anti-autoimmune diseases compounds.

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

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 461 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.

Protein serine/threonine kinases (PSKs) are protein kinases that use ATP as a high-energy donor molecule to transfer phosphate groups to serine/threonine residues of target protein. As an important signal transduction regulator, serine/threonine kinases can affect the function of target proteins by disrupting enzyme activity or binding of target proteins to other proteins. Serine/threonine kinases are involved in the regulation of immune response, cell proliferation, differentiation, apoptosis and other physiological processes. Serine/threonine kinase inhibitors are an important class of compounds that have been widely studied in cancer, chronic inflammation, autoimmune diseases, aging and other diseases.

MCE designs a unique collection of 1286 serine/threonine kinase inhibitors, mainly targeting the receptor PKA, Akt, PKC, MAPK/ERK, etc, which is an effective tool for development and research of anti-cancer, anti-chronic inflammatory diseases, anti-autoimmune diseases and anti-aging compounds.

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 487 compounds with identified and potential antihypertensive activity. MCE Antihypertensive Compound Library is critical for antihypertensive drug discovery and development.

Diabetes mellitus, usually called diabetes, is a group of metabolic disorders characterized by a high blood sugar level over a prolonged period of time. The most common types are Type I and Type II. Type I diabetes (T1D), also called juvenile onset diabetes mellitus or insulin-dependent diabetes mellitus, is characterized by destruction of the β-cells of the pancreas and insulin is not produced, whereas type II diabetes (T2D), also called non-insulin-dependent diabetes mellitus, is characterized by a progressive impairment of insulin secretion and relative decreased sensitivity of target tissues to the action of this hormone. Type 2 diabetes accounts for the vast majority of all diabetes mellitus. Diabetes of all types can lead to complications in many parts of the body and can increase the overall risk of dying prematurely. Possible complications include kidney failure, leg amputation, vision loss and nerve damage.

The pathogenesis of diabetes is complicated, and development of the safe and effective drugs against diabetes is full of challenge. Increasing studies have confirmed that the pathogenesis of diabetes is related to various signaling pathways, such as insulin signaling pathway, AMPK pathway, PPAR regulation and chromatin modification pathways. These signaling pathways have thus become the major source of the promising novel drug targets to treat metabolic diseases and diabetes.

MCE Anti-diabetic Compound Library owns a unique collection of 748 compounds, which mainly target SGLT, PPAR, DPP-4, AMPK, Dipeptidyl Peptidase, Glucagon Receptor, etc. This library is a useful tool for discovery anti-diabetes drugs.

A membrane protein is a protein molecule that is attached to or associated with the membrane of a cell or an organelle. Membrane proteins can be classified into two groups based on how the protein is associated with the membrane: integral membrane proteins and peripheral membrane proteins. In humans, about 30% genome encodes membrane proteins. Membrane proteins perform a variety of functions vital to the survival of organisms, for example, signal transduction, molecules or ion transportation, enzymatic catalysis, and intercellular communication. Membrane proteins also play important roles in drug discovery. As reported, more than 60% of current drug targets are membrane proteins.

MCE supplies a unique collection of 6927 compounds targeting a variety of membrane proteins. MCE Membrane Protein-targeted Compound Library can be used for membrane protein-focused screening and drug discovery.

Parkinson’s disease (PD), the second most common age-associated neurodegenerative disorder, is characterized by the loss of dopaminergic (DA) neurons and the presence of α-synuclein-containing aggregates in the substantia nigra pars compacta (SNpc). Motor features such as tremor, rigidity, bradykinesia and postural instability are common traits of PD. To date, there is no treatment to stop or at least slow down the progression of the disease. The etiology and pathogenesis of PD is still elusive, however, a large body of evidence suggests a prominent role of oxidative stress, inflammation, apoptosis, mitochondrial dysfunction and proteasome dysfunction in the pathogenesis of PD.

MCE offers a unique collection of 1354 compounds with anti- Parkinson’s Disease activities or targeting the unique targets of PD. MCE Anti- Parkinson's Disease Compound Library is a useful tool for exploring the mechanism of PD and discovering new drugs for PD.

The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway is central to signaling by cytokine receptors, a superfamily of more than 30 transmembrane proteins that recognize specific cytokines, and is critical in blood formation and immune response. Canonical JAK/STAT signaling begins with the association of cytokines and their corresponding transmembrane receptors. Activated JAKs then phosphorylate latent STAT monomers, leading to dimerization, nuclear translocation, and DNA binding. In mammals, there are four JAKs (JAK1, JAK2, JAK3, TYK2) and seven STATs (STAT1, STAT2, STAT3, STAT4, STAT5a, STAT5b, STAT6). Since the JAK/STAT pathway plays a major role in many fundamental processes, such as apoptosis and inflammation, dysfunctional proteins in the pathway may lead to a number of diseases. For example, alterations in JAK/STAT signalling can result in cancer and diseases affecting the immune system, such as severe combined immunodeficiency disorder (SCID).

MCE provides 424 compounds that can be used in the study of the JAK/STAT signaling pathway and related diseases.

Angiogenesis is the physiological process through which new blood vessels are formed from pre-existing vessels. It occurs in various physiological processes e.g. embryonic development, menstrual cycle, exercise and wound healing etc. Angiogenesis is regulated by both endogenous activators and inhibitors. Some key activators of angiogenesis include vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), angiogenin, TGF-β, etc. whereas angiogenesis inhibitors are angiostatin, endostatin, interferon, platelet factor 4, etc. The loss of balance between these opposing signals leads to life threatening diseases like cancer, cardiovascular and ischemic diseases etc. which are thus controlled by exogenous angiogenesis activators (for cardiovascular/ischemic disorders) and inhibitors (for cancer).

MCE offers a unique collection of 2003 compounds with validated angiogenesis targets modulating properties. MCE angiogenesis-related compound library is an effective tool for angiogenesis research and discovery of angiogenesis-related 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 1390 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.

Lung cancer is a major global health problem, as it is the leading cause of cancer-related deaths worldwide. Lung cancer is divided into two categories: small cell lung cancer and non-small cell lung cancer (NSCLC). Non-small cell lung cancer accounts for about 85 percent of lung cancers.

As with all cancers, lung cancer may be treated with surgery, chemotherapy, radiation therapy, targeted therapy, immunotherapy or a combination thereof. Targeted therapy is one of the most exciting developments in lung cancer medicine, especially for NSCLC. Extensive genomic characterization of NSCLC has led to the identification of molecular subtypes of NSCLC that are oncogene addicted and exquisitely sensitive to targeted therapies. These include activating mutations in epidermal growth factor receptor (EGFR) and BRAF or echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) fusions and ROS1 receptor tyrosine kinase fusions. These are important targets for target therapy.

MCE offers a unique collection of 1856 compounds with identified and potential anti-lung cancer activity. These compounds target lung cancer’s major targets and signaling pathways. MCE anti-lung cancer compound library is a useful tool for anti-lung cancer drugs screening and other related research.

Bioactive compounds are a general term for a class of substances that can cause certain biological effects in the body, which are the main source of small molecule drugs. These compounds generally penetrate cell membranes, act on specific target proteins in cells, regulate intracellular signaling pathways, and cause some changes in cell phenotype.

MCE owns a unique collection of 18934 compounds with confirmed biological activities and clear targets. These compounds include natural products, innovative compounds, approved compounds, and clinical compounds. These can also be used for signal pathway research, drug discovery and drug repurposing, etc.

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 1479 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.

Breast cancer is the most frequent cancer among women, impacting 2.1 million women each year, and also causes the greatest number of cancer-related deaths among women. Surgery is usually the first type of treatment for breast cancer, which is usually followed by chemotherapy or radiotherapy or, in some cases, hormone or targeted therapies, especially for metastatic breast cancer (MBC).

Breast cancer is a heterogeneous disease, which is categorized into 3 major subtypes based on the presence or absence of molecular markers for estrogen or progesterone receptors and human epidermal growth factor 2 (ERBB2; formerly HER2): hormone receptor positive/ERBB2 negative (70% of patients), ERBB2 positive (15%-20%), and triple-negative (tumors lacking all 3 standard molecular markers; 15%). Different intrinsic subtypes exhibit different tumor behavior with different prognoses, and may require specific targeted therapies to maximize treatment effectiveness. Otherwise, some signaling pathways also play important roles in the development of breast cancer, such as NF-κB Signaling Pathway, TGF-beta Signaling Pathway, PI3K/AKT/mTOR signaling pathway and Notch Signaling Pathway. These signaling pathways offer ideal targets for development of new targeted therapies for breast cancer.

MCE supplies a unique collection of 1968 compounds with identified and potential anti-breast cancer activity. MCE Anti-Breast Cancer Compound Library is a useful tool for anti-breast cancer drugs screening.

Extracellular vesicles (EVs) are small membrane binding structures that are released from cells into the surrounding environment and play a crucial role in mediating and regulating intercellular communication related to physiological and pathological processes. EVs are lipid membrane vesicles composed of proteins, lipids, and nucleic acids. EVs can be divided into several types based on their source, such as extracellular vesicles, microcapsules, and apoptotic vesicles. The size range of exosomes is 30-150nm, which are endocrine in multi vesicular endosomes (MVEs); microvesicles (50-1000nm) are secreted directly through extracellular interactions, thereby releasing plasma membrane vesicles. In contrast, apoptotic bodies are usually larger, ranging in size from 1 to 5 μ m. This is generated during programmed cell death. EV plays a crucial role in transmitting information between cells and influencing the behavior and function of receptor cells.

MCE designs a unique collection of 406 small molecules related to extracellular vesicles (EVs). It is a good tool to be used for research on metabolize, cancer and other diseases.

Inflammasomes are classic pattern recognition receptors for natural immune responses. Inflammasomes are polymeric protein complexes that regulate inflammatory responses and pyrolytic cell death, thereby exerting the host's defense against microorganisms. Inflammasomes sensors are associated with adapter proteins, activating inflammatory caspase-1, releasing inflammatory cytokines and inducing cell death, endowing the host with defense against pathogens. NLRP1, NLRP3, NLRC4, AIM2, and pyrin are considered typical inflammasomes because they convert cysteine asparaginase-1 into catalytically active capsaicin-1. In addition to infectious diseases, the importance of inflammasomes is also related to various clinical diseases, such as autoimmune diseases, neurodegeneration and metabolic disorders, and the development of cancer. Therefore, it is necessary to strictly regulate the activation and function of inflammasomes to avoid accidental host tissue damage while inducing pathogens to kill the inflammatory response.

MCE designs a unique collection of 68 inflammasomes related compounds. It is a good tool to be used for research on Inflammation, cancer and other diseases.

An emerging drug design method is based on the secondary binding site effect, where small molecule drugs are designed to bind to secondary binding sites on target biomolecules rather than primary orthomorphic sites. Successful potential drugs (known as allosteric modulators) will be able to bind to allosteric sites and remotely alter (or modify) the conformation of the main orthosteric binding sites of biological targets. Allosteric modulators (AMs) are ligands of proteins that act through binding sites different from natural (orthosteric) ligand sites. AMs are relatively small, more lipophilic, and more rigid compounds. The binding efficacy of AMs with their targets is often slightly lower. AMs are divided into positive AMs (PAMs) and negative AMs (NAMs). AMs are ideal drug targets because they can fine-tune receptor activity while preserving the spatial and temporal signal transduction characteristics of endogenous ligands, resulting in fewer targeted side effects, improved subtype selectivity, and better promotion of biased signal transduction than normal ligands.

MCE designs a unique collection of 178 small allosteric modulators. It is a good tool to be used for research on metabolize, cancer and other diseases.

Ion channel is a membrane-binding enzyme whose catalytic site is an ion conduction pore, which is opened and closed in response to specific environmental stimuli (voltage, ligand concentration, membrane tension, temperature, etc.). Ion channel provide pores for the passive diffusion of ions on the biofilm. Due to their high selectivity for ion, ion channel are generally classified as sodium (Na⁺ ), potassium (K⁺ ), calcium (Ca²⁺ ), chloride (Cl^- ), and non-specific cation channel. Ion channel is an important contributor to cell signal transduction and homeostasis. In addition to electrical signal transduction, ion channel also have many functions: regulating vascular smooth muscle contraction, maintaining normal cell volume, regulating glandular secretion, protein kinase activation, etc. Therefore, dysfunction of ion channel can lead to many diseases, and its mechanism research is particularly important.

MCE designs a unique collection of 1129 small molecules related to ion channel, mainly targeting Na⁺ channel, K⁺ channel, Ca²⁺ channel, GABA receptor, iGluR, etc. It is an essential tool for research of cardiovascular diseases, Nervous system diseases and other diseases.

Protein protein interactions (PPI) have pivotal roles in life processes. The studies showed that aberrant PPI are associated with various diseases, including cancer, infectious diseases, and neurodegenerative diseases. The classic drug targets are usually enzymes, ion channels, or receptors, the PPI indicate new potential therapeutic targets. Therefore, targeting PPI is a new direction in treating diseases and an essential strategy for the development of new drugs.

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.

With the development of high-throughput technology, high-throughput screening is also gradually used for the identification of PPI inhibitors, but the compound library used for conventional target screening is not very effective in screening PPI inhibitors. To improve screening efficiency, MCE carefully selected 583 PPI inhibitors and mainly targeting MDM2-p53, Keap1-Nrf2, PD-1/PD-L1, Myc-Max, etc. MCE Protein-protein Interaction Inhibitor Library is a useful tool for PPI drug discovery and related research.

The PI3K/Akt/mTOR pathway controls many cellular processes that are important for the formation and progression of cancer, including apoptosis, transcription, translation, metabolism, angiogenesis, and cell cycle progression. Every major node of this signaling network is activated in a wide range of human tumors. Mechanisms for the pathway activation include activation of receptor tyrosine kinases (RTKs) upstream of PI3K, mutation or amplification of PIK3CA encoding p110α catalytic subunit of PI3K, mutation or loss of PTEN tumor suppressor gene, and mutation or amplification of Akt1. Once the pathway is activated, signaling through Akt can stimulate a series of substrates including mTOR which is involved in protein synthesis. Thus, inhibition of this pathway is an attractive concept for cancer prevention and/or therapy. Currently some mTOR inhibitors are approved for several indications, and there are several novel PI3K/Akt/mTOR inhibitors in clinical trials.

MCE owns a unique collection of 575 compounds that can be used for PI3K/Akt/mTOR pathway research. PI3K/Akt/mTOR Compound Library also acts as a useful tool for anti-cancer drug discovery.