Drug discovery

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

MCE offers a unique collection of 418 macrocyclic compounds which can be used for drug discovery for high throughput screening (HTS) and high content screening (HCS). MCE Macrocyclic Compound Library is a useful tool for discovering new drugs, especially for “undruggable” targets and protein–protein interactions.

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

MCE provides a unique collection of 5,491 natural compounds and natural product-like compounds that contain saccharides and glycosides, phenylpropanoids, quinones, flavonoids, terpenoids and glycosides, steroids, alkaloid, phenols, acids and aldehydes. Natural product and natural product-like compounds library is a useful tool for drug discovery that can be used for high-throughput screening (HTS) and high-content screening (HCS).

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 6,207 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.

Nature has been a source of medicinal products for millennia, with many useful active substances developed from plant sources. In the 20th century, the discovery of the penicillin was the starting point for drug discovery from microbial sources. Microorganisms， which have been considered to be a rich source of unique bioactive compounds, play an important role in the development of the chemistry of natural products and medical therapy. Microbial metabolites have proved to be affective antimicrobial agents, anti-tumor agents, enzyme inhibitors, anti-inflammatory agents, etc. Today, many microbial-originated antibiotics are available in the mark, and a large number of bioactive metabolites are used in medicine.

MCE provides a unique collection of 881 microbial metabolites, which is an important source of lead compounds and can be used for drug discovery.

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 747 protease inhibitors. MCE Protease Inhibitor Library is critical for drug discovery and development.

From target identification to clinical research, traditional drug discovery and development is a time-consuming and costly process, which also bears high risk. Compared with traditional drug discovery, drug repositioning or repurposing, also known as old drugs for new uses can greatly shorten the development cycle and reduce development cost, which has become a new trend of drug development. After undergoing clinical trials, approved drugs have identified bioactivities, good pharmacokinetic characteristics and safety, which can greatly improve the success rate of drug discovery. A number of successes have been achieved, such as metformin for type 2 diabetes and thalidomide for leprosy and multiple myeloma, etc.

MCE provides a unique collection of 1,395 China NMPA (National Medical Products Administration) approved compounds, which have undergone extensive preclinical and clinical studies and have well-characterized bioactivities, safety and bioavailability properties. MCE NMPA-Approved Drug Library is a good tool for drug repurposing which could dramatically accelerate drug development.

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

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

MCE offers a unique collection of 61 marine-sourced natural products which can be used for drug discovery for high throughput screening (HTS) and high content screening (HCS). MCE marine-sourced natural product library is an important source for drug discovery and development.

Natural products are small molecular compounds that occur in nature and come from any organism, including primary and secondary metabolites. Natural products have potential biological activity and can be used as lead compounds for drug discovery. Nature has been a source of medicines for thousands of years, and a large number of drugs have been isolated from nature, many based on their use in traditional medicine. With the development of compound targets, there is an increasing need to screen for compound diversity. Through ongoing research into natural biodiversity, much of which remains to be exploited, natural products will play a key role in meeting this demand. The Lipinski rule of 5 is used to describe the drug-like properties of a molecule, molecules that adhere to the rule of 5 have higher drug potential. Based on MCE natural product library, MCE selects the molecules that obey the rule of 5, which makes the efficiency of drug screening higher.

MCE designs a unique collection of 2,666 RO5 drug-like natural products, which is an important tool for drug discovery.

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

MCE provides a unique collection of 1,022 animal-sourced natural products. MCE Animal-Sourced Natural Product Library is a useful tool for drug discovery that can be used for high throughput screening (HTS) and high content screening (HCS).

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

MCE designs a unique collection of 23,340 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.

Increasing research have shown that Traditional Chinese Medicine (TCM) possess antiviral activities against various viral strains, such as herpes simplex virus, influenza virus, hepatitis B and C viruses, and SARS-CoV. To date, dozens of Chinese herbs and hundreds of natural TCM ingredients have been reported to exhibit good antiviral activities. Active components from TCM are one of the important sources for antiviral drugs discovery.

MCE designs a unique collection of 176 active compounds of antiviral Chinese Herbal Medicines. MCE Antiviral Traditional Chinese Medicine Active Compound Library is a useful tool for discovery antiviral drugs from TCM.

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

MCE owns a unique collection of 877 human endogenous metabolites, all of which are derived from human issues. This library is a powerful tool for metabonomics research and metabolism-related drug discovery.

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.

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

The MCE 1K Drug Fragment Library consists of 1,168 drug fragments. These drug fragments are derived from 2,946 FDA-approved drug molecules, and fragments from one drug can appear in other drugs, so these fragments are somewhat correlated with good PK/PD properties. Fragment-based screening can reserve enough chemical space for subsequent structural optimization. This compound library is an essential tool for drug screening based on FBDD (Fragment-Based Drug Discovery).

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 high-throughput bioactive compound library integrates 25,435 spot and futures bioactive compounds with confirmed biological activities and clear targets. These compounds can also be used for signal pathway research, drug discovery and drug repurposing, etc.

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 2,933 small molecules targeting GPCRs that can be used in the screening for various GPCRs-related research and drug development projects.

Natural products are small molecules produced naturally by any organism including primary and secondary metabolites. Natural sources may lead to basic research on potential bioactive components for commercial development as lead compounds in drug discovery.

Nature has been a source of medicinal agents for thousands of years, and an impressive number of modern drugs have been isolated from natural sources, many based on their use in traditional medicine. With the development of new molecular targets, there is an increasing demand for novel molecular diversity for screening. Natural products will play a crucial role in meeting this demand through the continued investigation of world’s bio-diversity, much of which remains unexplored.

MCE provides a unique collection of 4,816 natural compounds that contain Saccharides and Glycosides, Phenylpropanoids, Quinones, Flavonoids, Terpenoids and Glycosides, Steroids, Alkaloid, Phenols, Acids and Aldehydes. Natural Product Library is a useful tool for drug discovery that can be used for high throughput screening (HTS) and high content screening (HCS).

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

MCE offers a unique collection of 1,457 approved drugs with anti-cancer activity, which can be used for discovery of new anti-cancer drugs or as positive compounds used for anti-cancer research.

Kinase is an enzyme that adds phosphate groups to other molecules. This process is known as phosphorylation. Protein phosphorylation is a key aspect in the regulation of a large number of cellular processes including cellular division, metabolism, signal transduction, and so on. There are over 500 kinases encoded by the human genome and it has been estimated that kinases regulate approximately 50% of cellular functions. Kinases are a large group of drug targets in drug discovery. Kinase inhibitors are an important class of drugs that block certain enzymes involved in diseases such as cancer and inflammatory disorders.

Kinase inhibitor library designed by MCE contains 3,312 kinase inhibitors and regulators mainly targeting protein kinases (VEGFR, EGFR, BTK, CDK, Akt, etc.), lipid kinases (PI3K, PI4K, SK, etc.) and carbohydrate kinases (Hexokinase), and is a useful tool for kinase drug discovery and related research.

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 8,811 compounds targeting a variety of membrane proteins. MCE Membrane Protein-targeted Compound Library can be used for membrane protein-focused screening and drug discovery.

Natural products are characterized by enormous scaffold diversity and structural complexity, because of which, natural products do show a wide range of biological activities. Medicinal plants have been the major source of medicines over many centuries. About a quarter of all Food and Drug Administration (FDA) and/or the European Medical Agency (EMA) approved drugs are plant based, with well-known drugs such as Paclitaxel and Aspirin having been isolated from plants.

MCE provides a unique collection of 2,948 plant-sourced natural products. MCE Plant-Sourced Natural Product Library is a useful tool for drug discovery that can be used for high throughput screening (HTS) and high content screening (HCS).

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 1,986 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.

With features of enormous scaffold diversity and structural complexity, natural products (NPs) are the main sources of lead compounds and new drugs and play a highly significant role in the drug discovery and development process, especially for cancer and infectious diseases. A large number of natural products have been proven to have potential anti-tumor effects, mainly from plants, animals, Marine organisms and microorganisms. At present, derived than 60% of anti-tumor drugs come from natural sources, and they are widely used in breast, prostate and colon cancers.

MCE offers a unique collection of 1,803 natural products with validated anti-cancer activity. MCE anti-cancer natural product library is a useful tool for anti-tumor drugs screening and other related research.

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.

Phenolic compounds are usually referred to as a diverse group of naturally occurring compounds with multiple medical properties, such as antioxidants, antimicrobial properties. Those compounds are commonly found in food and plants. They have high synthetic, medicinal and industrial values. Polyphenols are compounds with multiple phenolic functionalities. Naturally occurring polyphenols are known to have biological activities for use as drugs, for example, in diseases like AIDS, heart ailments, ulcer formation, bacterial infection, mutagenesis and neural disorders.

MCE offers a unique collection of 1,208 natural phenol compounds which is a useful tool for drug discovery as an important source of lead compounds.

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 171 GABA receptors inhibitors and activators, which is an efficient tool for neuropsychiatric disorders drugs discovery.

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.

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 5,897 compounds targeting a variety of membrane receptors. MCE Membrane reeptor-targeted Compound Library can be used for membrane receptor-focused screening and drug discovery.

Fragment-based drug development (FBDD) is a strategy for drug discovery that can be applied both academically and commercially to enhance the identification of some non-drug targets. Fragment-based drug development has identified low molecular weight molecules (<300 Da) capable of binding to related macromolecules. These fragments can cover a wide chemical space and are easy to optimize later. Currently, several fragment-based drugs have entered clinical trials, of which two drugs, Vemurafenib and Venetoclax, have been approved for marketing.

Based on Tanimoto coefficient, MCE uses similarity algorithm to carefully select 2,302 high-structurally diverse 'RO3' compliant fragment molecules from large-scale fragment molecules, which can be applied to fragment based drug development.

The blood-brain barrier (BBB) is the complex network of brain microvessels. It protects the brain from the external bloodstream environment and supplies the brain with the required nutrients for normal function. However, blood-brain barrier is also the obstacle to deliver beneficial drugs to treat CNS (central nervous system) diseases or brain tumors, as it has the least permeable capillaries in the entire body due to physical barriers (tight junctions). Therefore, it is crucial to discover drugs which can cross this barrier for the treatment of brain-based diseases, such as Alzheimer’s disease (AD), Parkinson’s disease (PD) and epilepsy.

MCE offers a unique collection of 1,002 compounds with confirmed CNS-Penetrant property. It’s a useful tool for the discovery of drugs used for brain diseases, such as brain tumors, mental disorders, and neurodegenerative diseases.

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 22,050 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.

Traditional Chinese medicine provides abundant natural resources for medicinal compounds, which are often considered effective and safe for drug discovery. Traditional Chinese medicine is based on the principle of "multiple components, multiple targets, and multiple pathways", and naturally has multiple pharmacological effects. As herbal medicine, the secondary plant metabolites in Chinese herbal medicine play an important role in alleviating many diseases in Traditional medicine and folk use. Therefore, the identification of traditional Chinese medicine derived compounds is also an important process in drug development and a necessary factor in dissecting the overall mechanism of action of traditional Chinese medicine. FDA listed compounds have completed extensive preclinical and clinical studies, exhibiting good biological activity, safety, and bioavailability.

MCE designs a unique collection of 335 FDA-approved traditional Chinese medicine active compounds, including flavonoids, polyphenols, alkaloids, terpenoids, and other structural types. It is a good tool for drug reuse and screening drugs from traditional Chinese medicine sources.

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 2,829 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.

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

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 covalent inhibitor library contains 1,430 small molecules including identified covalent inhibitors and other bioactive molecules having common covalent reactive groups as warheads, such as acrylamides, activated terminal acetylenes, Sulfonyl fluorides/esters, cloracetamides, alkyl halides, epoxides, aziridines, disulfides, etc.

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

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

Terpenoids, also known as isoprenoids, are the most numerous and structurally diverse natural products found in many plants. Terpenoids are divided into monoterpenes, sesquiterpenes, diterpenes, sesterpenes, and triterpenes depending on its carbon units. Several studies, in vitro, preclinical, and clinical have confirmed that this class of compounds displays a wide array of very important pharmacological properties in the fight against cancer, malaria, inflammation, and a variety of infectious diseases. Naturally occurring terpenoids provide new opportunities to discover new drugs with minimum side effects.

MCE designs a unique collection of 686 terpenoid compounds that all come from natural products. MCE Terpenoids Library is a useful tool for drug discovery that can be used for high throughput screening (HTS) and high content screening (HCS).

Cyclic peptides are polypeptide chains taking cyclic ring structure, which exhibit diverse biological activities, such as antibacterial activity, immunosuppressive activity and anti-tumor activity. Cyclic peptides, with the features of good binding affinity, target selectivity and low toxicity, show great success as therapeutics. Multiple cyclic peptides are currently in clinical use, for examples, gramicidin and tyrocidine with bactericidal activity, cyclosporin A with immunosuppressive activity, and vancomycin with antibacterial activity. Furthermore, cyclic peptides usually have the sufficient size and a balanced conformational flexibility/rigidity for binding to flat protein-protein interaction (PPI) interfaces, which have potential to develop PPI drugs.

MCE offers a unique collection of 92 cyclic peptides, all of which have good bioactivities. MCE Cyclic Peptide Library is a powerful tool for drug discovery and PPI inhibitor screening.

With the aging population and increasing competitive pressures, neurodegenerative diseases of the central nervous system (CNS) have become a serious medical challenge in modern society, including Parkinson's disease, Alzheimer's disease, brain tumors, and multiple sclerosis. However, the success rate of CNS drug development remains remarkably low, primarily due to the blood-brain barrier (BBB). The blood-brain barrier (BBB) is a semipermeable barrier structure that surrounds the microvasculature of the CNS. In capillaries, the wedged endothelial cells are tightly packed and wedge-shaped, lining the interior of the vessels to form extensive tight junctions. Along with a range of receptors, transporters, efflux pumps, and other cellular components, this barrier regulates the entry and exit of molecules between the bloodstream and the brain. The intact BBB blocks the passage of most blood-borne substances into the brain, preventing nearly 100% of large-molecule drugs and over 98% of small-molecule drugs from entering. Compared to non-CNS drugs, physicochemical properties such as hydrogen bonds, lipophilicity, and molecular weight significantly influence a compound's ability to cross the BBB. Using artificial intelligence (AI) algorithms to predict BBB permeability, a predicted value greater than 0.75 indicates that the compound has strong potential to cross the BBB, providing a promising starting point for CNS drug discovery.

Mitochondria plays an important role in many vital processes in cells, including energy production, fatty-acid oxidation and the Tricarboxylic Acid (TCA) cycle, calcium signaling, permeability transition, apoptosis and heat production. At present, it is recognized that many diseases are associated with impaired mitochondrial function, such as increased accumulation of ROS and decreased OXPHOS and ATP production. Mitochondria are recognized as one of the most important targets for new drug design in cancer, cardiovascular, and neurological diseases, etc. Some small molecule drugs or biologics can act on mitochondria through various pathways, including ETC inhibition, OXPHOS uncoupling, mitochondrial Ca²⁺ modulation, and control of oxidative stress via decrease or increase of mitochondrial ROS accumulation.

MCE supplies a unique collection of 860 mitochondria-targeted compound that mainly targeting Mitochondrial Metabolism, ATP Synthase, Mitophagy, Reactive Oxygen Species, etc. MCE Mitochondria-Targeted Compound Library is a useful tool for mitochondria-targeted drug discovery and related research.

Food additives are substances added to food to maintain or improve its safety, freshness, taste, texture, or appearance. All food additives used in food undergo a safety assessment, which includes rigorous testing, before they are approved, so all food additives are generally recognized as safe substances.

MCE supplies 414 approved food additives which are safe substances and can be used for drug discovery and other research.

Natural products are an attractive source with varied structures that exhibit potent biological activities, and desirable pharmacological profiles. The core scaffold of a natural product can also provide a biologically validated framework upon which to display diverse functional groups. Inspired by bioactive natural products, natural product-like compounds, occupying the same chemical space, are ideally suited to explore and to facilitate understanding of biological pathways.

MCE provides a unique collection of 689 natural product-like compounds that are structurally like Steroids, Tannins, Flavonoids, Quinones, Isoquinolines, etc. This library is an important source of lead compounds for drug discovery.

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 covalent inhibitor library contains 5,794 small molecules including identified covalent inhibitors and other molecules having common covalent reactive groups as warheads, such as acrylamides, activated terminal acetylenes, sulfonyl fluorides/esters, cloracetamides, alkyl halides, epoxides, aziridines, disulfides, etc.

MCE Covalent inhibitor Library plus, with more powerful screening capability, further complement Covalent inhibitor Library (HY-L036) by adding some fragment compounds with covalent warheads.