and drug development

An inactive ingredient is any component of a drug product other than the active ingredient. Inactive ingredients are added during the manufacturing process of pharmaceutical products such as tablets, capsules, suppositories, and injections. In new drug development, once an inactive ingredient has appeared in an approved drug product for a particular route of administration, the inactive ingredient is not considered new and may require a less extensive review the next time it is included in a new drug product.

MCE offers a unique collection of 168 inactive ingredients, which only contain inactive ingredients of the final dosage forms of the drug. MCE Inactive Ingredient library is a powerful tool for aiding in the development of the drug and saving unnecessary time.

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 1,755 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.

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 1,411 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.

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 3,331 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.

New drug development is a time-consuming and high-cost process. Drug repurposing (also called drug repositioning, reprofiling or re‑tasking) offers various advantages over developing an entirely new drug for a given indication. First, the risk of failure is lower. Second, the time frame for drug development can be reduced. Third, less investment is needed. Approved drugs have identified bioactivities, good pharmacokinetic characteristics and safety which are suitable for drug repurposing.

MCE owns a unique collection of 3,074 approved compounds which have been completed extensive preclinical and clinical studies and have well-characterized bioactivities, safety and bioavailability properties. MCE FDA-Approved Drug Library is a good tool for drug repurposing which could dramatically accelerate drug development.

New drug development is a time-consuming and high-cost process. Drug repurposing (also called drug repositioning, reprofiling or retasking) offers various advantages over developing an entirely new drug for a given indication. First, the risk of failure is lower. Second, the time frame for drug development can be reduced. Third, less investment is needed. Approved drugs and pharmacopoeia collected compounds have identified bioactivities, good pharmacokinetic characteristics and safety which are suitable for drug repurposing.

MCE owns a unique collection of 3,585 compounds from approved institutions such as FDA, EMA, NMPA, PMDA, etc. or pharmacopoeia such as USP, BP, JP, etc. These compounds have well-characterized bioactivities, safety and bioavailability properties. MCE FDA Approved & Pharmacopeial Drug Library is a good tool for drug repurposing which could dramatically accelerate drug development.

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 2,305 high-structurally diverse 'RO3' compliant fragment molecules from large-scale fragment molecules, which can be applied to fragment based drug development.

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

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 2,832 small molecules targeting GPCRs that can be used in the screening for various GPCRs-related research and drug development projects.

New drug development is a time-consuming and high-cost process. Drug repurposing (also called drug repositioning, reprofiling or re‑tasking) offers various advantages over developing an entirely new drug for a given indication. First, the risk of failure is lower. Second, the time frame for drug development can be reduced. Third, less investment is needed. Approved and clinical drugs, especially after phase I drugs, have identified bioactivities, good pharmacokinetic characteristics and safety which are suitable for drug repurposing.

MCE Drug Repurposing Compound Library contains 5,080 approved drugs and passed phase Ⅰclinical drugs, which have been completed extensive preclinical and clinical studies and have well-characterized bioactivities, safety and bioavailability properties.

New drug development is a time-consuming and high-cost process. Drug repurposing (also called drug repositioning, reprofiling or re‑tasking) offers various advantages over developing an entirely new drug for a given indication, such as lower risk and less investment. Clinical drugs have confirmed bioactivities, clear mechanisms and high safety that are suitable for drug repurposing.

MCE owns a unique collection of 2,641 clinical compounds that refer to various research areas including anti-cancer, anti-infection, anti-inflammation, nervous disease. Those compounds are of detailed information on clinical development status, research area, targets, etc.

The occurrence of diseases is often associated with multiple targets and pathways, and the factors of disease formation are complex and diverse, so the development of more powerful drugs is needed. According to statistics, 21% of the FDA-approved drugs in 2015-2017 were multi-target compounds. Multi-target compounds refer to a drug targeting multiple disease-related targets or multiple subtypes of a target. Multi-target compounds can be applied to drug screening or targeted ligand design. Because the targets of such compounds are diverse and clear, they have the characteristics of saving time and drug cost during the mechanism research of new drug research and development. In addition, due to the diversity of drug targets, multiple strategies can be applied to pharmacological studies.

MCE supplies a unique collection of 4,883 multi-target compounds that targets two or more different targets or different subtypes of the same target. MCE Multi-Target Compound Library can be used for target protein ligand screening or drug development.

MCE EMA-Approved Drug Library consists of 694 EMA-approved drugs with high pharmacological diversity. All drugs in this library have been completed extensive preclinical and clinical studies and have well-characterized bioactivities, safety and bioavailability properties. MCE EMA-Approved Drug Library is a useful tool for drug repurposing which could dramatically accelerate drug development.

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 4,727 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 6,164 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.

New drug development is a time-consuming and high-cost process. Drug repurposing (also called drug repositioning, reprofiling or re‑tasking) offers various advantages over developing an entirely new drug for a given indication. First, the risk of failure is lower. Second, the time frame for drug development can be reduced. Third, less investment is needed. Approved drugs have identified bioactivities, good pharmacokinetic characteristics and safety which are suitable for drug repurposing.

MCE owns a unique collection of 3,074 approved compounds which have been completed extensive preclinical and clinical studies and have well-characterized bioactivities, safety and bioavailability properties. The package of this library is 96-well microplate with peelable foil seal, which makes the screening process easier and faster.

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

Rare diseases are an important public-health issue and a challenge for the medical community. Most rare diseases are genetic disorders, which are often severely disabling, substantially affect life expectancy, and impair physical and mental abilities. Currently, there are about 7,000 identified rare diseases, together affecting 10% of the population. However, fewer than 6% of all rare diseases have an approved treatment option, highlighting their tremendous unmet needs in drug development. The process of repurposing drugs for new indications, compared with the development of novel orphan drugs, is a time-saving and cost-efficient method resulting in higher success rates, which can therefore drastically reduce the risk of drug development for rare diseases.

MCE carefully collects a unique of 1,793 compounds studied in preclinical, clinical trials or approved used in rare diseases treatment. MCE rare diseases drug library is a useful tool for the research of rare diseases. All compounds can provide corresponding indications for rare diseases.

New drug development is a time-consuming and high-cost process. Drug repurposing (also called drug repositioning, reprofiling or re‑tasking) offers various advantages over developing an entirely new drug for a given indication. First, the risk of failure is lower. Second, the time frame for drug development can be reduced. Third, less investment is needed. Approved drugs have identified bioactivities, good pharmacokinetic characteristics and safety which are suitable for drug repurposing.

MCE owns a unique collection of 3,436 approved compounds which have been completed extensive preclinical and clinical studies and have well-characterized bioactivities, safety and bioavailability properties. MCE FDA-Approved Drug Library Plus, with more powerful screening capability, further complements FDA-Approved Drug Library (HY-L022) by adding some compounds with low solubility or solution stability (Part B) to this library. All those supplementary are supplied in powder form.

New drug development is a time-consuming and high-cost process. Drug repurposing (also called drug repositioning, reprofiling or re‑tasking) offers various advantages over developing an entirely new drug for a given indication. First, the risk of failure is lower. Second, the time frame for drug development can be reduced. Third, less investment is needed. Approved and clinical drugs, especially after phase I drugs, have identified bioactivities, good pharmacokinetic characteristics and safety, which are suitable for drug repurposing.

MCE Drug Repurposing Compound Library plus contains 5,933 approved and passed phase I clinical drugs, which have been completed extensive preclinical and clinical studies and have well-characterized bioactivities, safety and bioavailability properties.

MCE Drug Repurposing Compound Library plus, with more powerful screening capability, further complement MCE Drug Repurposing Compound Library (HY-L035) by adding some compounds with low solubility or stability (Part B) to this library. All those supplementary compounds are supplied in powder form.

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 50 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.

COVID-19 poses a serious threat to people's health, and it is urgent to develop drugs to treat COVID-19 quickly. The screening of anti-COVID-19 drugs by using the clinical and approved compounds can greatly shorten the research and development cycle. In addition, the virtual screening technology can effectively narrow the scope of screening and improve the screening efficiency in the pre-screening of new drugs.

Taking advantage of our virtual screening, we conduct virtual screening of approved compound library and clinical compound library based on the 3CL protease (PDB ID: 6LU7), Spike Glycoprotein (PDB ID: 6VSB), NSP15 (PDB ID: 6VWW), RDRP, PLPro and ACE2 (Angiotensin Converting Enzyme 2) structure. We design a unique collection of 1,463 compounds which may have anti-COVID-19 activity. Anti-COVID-19 Compound Library will be a powerful tool for screening new anti-COVID-19 activity drugs.

New drug development is a time-consuming and high-cost process. Drug repurposing (also called drug repositioning, reprofiling or re‑tasking) offers various advantages over developing an entirely new drug for a given indication, such as lower risk and less investment. Clinical drugs have confirmed bioactivities, clear mechanisms and high safety that are suitable for drug repurposing.

MCE owns a unique collection of 3,285 clinical compounds that refer to various research areas including anti-cancer, anti-infection, anti-inflammation, nervous disease. Those compounds are of detailed information on clinical development status, research area, targets, etc. Clinical Compound Library Plus, with powerful screening capability, further complements Clinical Compound Library (HY-L026) by adding some compounds with low solubility or solution stability (Part B) to this library. All those supplementary are supplied in powder form.

Drug repurposing (also called drug repositioning, reprofiling, or re‑tasking) offers various advantages over developing an entirely new drug for a given indication, for example, lower risk of failure, less investment, and shorter development timelines. But drug repositioning projects are also subject to several risks, including regulatory and intellectual property issues. So the off-patent drugs are optimal for repositioning because of their immediate availability for clinical studies, with high feasibility and relatively low risk.

MCE carefully prepared a unique collection of 2,760 off-patent drugs, which is a good choice for drug repurposing.

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 1,450 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.

Resistance refers to the decrease in the effectiveness of drugs in treating diseases or symptoms. Due to the increasing global antibiotic resistance, it may threaten our ability to treat common infectious diseases. Drug resistance is also the main cause of chemotherapy failure in malignant tumors. In approximately 50% of cases, drug resistance exists even before chemotherapy begins. There are many mechanisms of anticancer drug resistance, including increased protein expression that leads to drug removal, mutations in drug binding sites, recovery of tumor protein production, and pre-existing genetic heterogeneity in tumor cell populations. In addition, the issue of drug resistance seems to have affected the development of new anticancer drugs. Drug resistance may be caused by various conditions, such as mutations, epigenetic modifications, and upregulation of drug efflux protein expression. Overcoming multidrug resistance in cancer treatment is becoming increasingly important.

MCE designs a unique collection of 456 anti-drug-resistant compounds. It is a good tool to be used for research on cancer and other diseases.

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

MCE contains 495 mitochondrial toxic compounds, which can be used as tool compounds for drug development and disease mechanism research.

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 656 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.

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

MCE offers a unique collection of 4,040 compounds with confirmed high oral bioavailability. MCE Orally Active Compound Library is a useful tool for discovering new drugs with oral bioavailability.

Normal mitochondrial function is critical for maintaining cellular homeostasis because mitochondria produce ATP and are the major intracellular source of free radicals. Cellular dysfunctions induced by intracellular or extracellular insults converge on mitochondria and induce a sudden increase in permeability on the inner mitochondrial membrane, the so-called mitochondrial membrane permeability transition (MMPT). MMPT is caused by the opening of pores in the inner mitochondrial membrane, matrix swelling, and outer membrane rupture. The MMPT is an endpoint to initiate cell death because the pore opening together with the release of mitochondrial cytochrome c activates the apoptotic pathway of caspases.

The normal operation of mitochondrial function is important for maintaining normal cell death and treatment of mitochondrial diseases. MCE offers a unique collection of 758 compounds with identified and potential mitochondrial protective activity. MCE Mitochondrial Protection Compound Library is critical for drug discovery and development.

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 255 small molecules target amino acid metabolizing enzymes, which is an important tool for studying studying amino acid metabolism processes or metabolism-related drug development.

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

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

MCE has sorted out 211 drug compounds withdrawn from the market through FDA, EMA and other authoritative platforms. Each compound has withdrawal records in at least one country/market. It is a useful tool for conducting research on drug side effects or drug toxicity mechanisms and discovering new indications of drugs.

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 4,770 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).

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

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

MCE Drug-induced Liver Injury (DILI) Compound Library contains a unique collection of 1,443 hepatotoxicity causing compounds and is a powerful tool to research DILI and other drug toxicities. This library can be used to understand the mechanisms of DILI, identify biomarkers for early DILI prediction, and allow timely recognition during drug development, thus finally achieving successful DILI prevention and assessment in the pre-marketing phase.

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 796 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.

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 1,745 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.

The lack of availability of appropriate medicines for children is an extensive and urgent problem. A variety of obstacles hinder children's drug development, including the limited commercial interest, lack of suitable infrastructure and competence for conducting paediatric clinical trials, difficulties in trial design, ethical worries and many others. Because of these factors, unlicensed and off-label prescribing is very common in children which may lead to safety concern.

MCE offers a unique collection of 684 Pediatric medicines, all of which have been approved or studied in clinical trials for children diseases. MCE children’s drug library is a useful tool for drug repurposing to discover new children’s indications.

Unlike the 20 natural amino acids commonly found within living organisms, unnatural 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, unnatural 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.

MCE included 119 unnatural amino acids and relative derivatives, serving as valuable tools for drug development and pesticide research.

Tuberculosis (TB), usually caused by bacteria (Mycobacterium tuberculosis), is an infectious disease that mainly affects the lungs. According to the statistics of the World Health Organization (WHO), 10 million people suffer from tuberculosis every year, and 1.5 million people die of tuberculosis every year, which makes tuberculosis the number one killer of infectious diseases.

Tuberculosis can be cured through the standard 6-month course of treatment of four kinds of antibiotics. Common drugs include rifampicin and isoniazid. In some cases, TB bacteria do not respond to standard drugs, that is, patients with drug-resistant tuberculosis. The treatment of drug-resistant tuberculosis takes longer and is more complex. In the face of the resurgence of tuberculosis in the world and the rapid emergence of multi drug resistant tuberculosis, it is very important to develop new anti-tuberculosis drugs or new clinical treatment schemes for existing anti mycobacterium drugs.

MCE supplies a unique collection of 116 compounds with clear anti-tuberculosis activity. MCE Anti-tuberculosis Compound Library is a useful tool for anti-tuberculosis related research and anti-tuberculosis drug 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 2,707 RO5 drug-like natural products, which is an important tool for drug discovery.

Protein Kinases (PTKs) are a class of phosphotransferases that phosphorylate proteins. Protein kinases participate in many signal transduction pathways including those involved with growth, differentiation, and cell division. Protein kinase not only plays an important role in the process of cell activation, but also its abnormal expression is closely related to the pathogenesis of many diseases. So far, the protein kinase family has become one of the most important drug targets. The most common drug targets include ALK, B-Raf, BCR-Abl, EGFR, and VEGFR.

MCE designs a unique collection of 3,261 bioactive compounds targeting protein kinases, which is an important tool for the development of drug targeting protein kinases.

Antibody inhibitors are compounds with the same activity as the original therapeutic antibodies, which can be used as positive controls for drug efficacy evaluation and other studies. Antibody inhibitors can also assist in verifying the functional activity of the target protein. These antibody inhibitors are active in vivo and can achieve certain physiological functions by blocking or neutralizing target proteins, such as CD20, HER2, EGFR, VEGFR, TNF-α, etc. In drug screening, antibody inhibitor-based screening can be carried out to identify active compounds targeting target proteins and target diseases.

MCE can provide 1,015 antibody inhibitors that can be used for drug development in cancer, immunity, infection and other hot research areas.

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

MCE offers a unique collection of 409 compounds with validated antifungal activities. MCE antifungal compound library is an effective tool for drug repurposing screening, combination screening and biological investigation.

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

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

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 332 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.

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 1,454 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.

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.

With the progress of modern cancer therapy, the life of cancer patients has been extended. However, after initial treatment and recovery, the development of secondary tumors often leads to cancer recurrence. Cancer stem cells are a small number of cells that tumor growth and reproduction depend on.

Cancer stem cells have strong self-renewal ability, which is the direct cause of tumor occurrence. In addition, cancer stem cells also have the ability to differentiate into different cell types, playing a crucial role in tumor metastasis and development. Chemotherapy and radiotherapy induced DNA damage and apoptosis are common cancer treatments. However, cancer stem cells can effectively protect cancer cells from apoptosis by activating DNA repair ability. Cancer stem cells are regarded as the key "seed" of tumor occurrence, development, metastasis and recurrence. Since its first discovery in leukemia in 1994, cancer stem cells have been considered a promising therapeutic target for cancer treatment.

MCE supplies a unique collection of 2,525 compounds targeting key proteins in cancer stem cells. MCE Cancer Stem Cells Compound Library is a useful tool for cancer stem cells related research and anti-cancer drug development.

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

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

MCE supplies a unique collection of 55 molecular glues which target various proteins. MCE Molecular Glue Compound Library is a useful tool to conduct scientific research and disease mechanism study.

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 5,630 natural compounds that contains Saccharides and Glycosides, Phenylpropanoids, Quinones, Flavonoids, Terpenoids and Glycosides, Steroids, Alkaloid, Phenols, Acids and Aldehydes. Natural Product Library Plus, with more powerful screening capability, further complements Natural Product Library (HY-L021) by adding some compounds with low solubility or solution stability (Part B) to this library. All those supplementary are supplied in powder form.