and neuroprotective effects.（±）-儿茶素(±)-Catechin 是Catechin的外消旋体。(±)-Catechin，从 <i>Acacia catechu</i> L. 中提取，具有两种形式( )-Catechin及其对映体（-）-Catechin。( )-Catechin 抑制环氧合酶-1（COX-1）的IC50为1.4μM。 (±)-Catechin 具有抗肿瘤，抗肥胖，抗糖尿病，抗心血管，抗感染，保肝和神经保护作用。

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.

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 Once the drug is withdrawn from the market, it will cause heavy losses to the original research company that invested a lot of time, finance and other costs to develop the drug.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 199 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.

Non-steroidal anti-inflammatory drugs (NSAIDs) are members of a therapeutic drug class with potent anti-inflammatory, analgesic and antipyretic activity, and are among the most widely used drugs worldwide. The most prominent NSAIDs are aspirin, ibuprofen, and naproxen.

The main mechanism of action of NSAIDs is the inhibition of the enzyme cyclooxygenase (COX), based on which NSAIDs can be classified into two types: non-selective and COX-2 selective. Most NSAIDs are non-selective and inhibit both COX-1 and COX-2 activity.

MCE offers a unique collection of 598 non-steroidal compounds with identified anti-inflammatory activity. MCE non-steroidal anti-inflammatory library is a useful tool for the study of anti-inflammatory drugs and pharmacology.

Pancreatic cancer is a devastating disease with a low overall survival rate. Chemotherapy is the most common treatment for patients presenting with advanced pancreatic cancer. More recently, the era of targeted therapies has generated a lot of interest in discovering better approaches for patients with pancreatic cancer. Commonly mutated genes in pancreatic cancer include K-ras (in 74-100% of cases), p16INK4a (up to 98%), p53 (43 to 76%), DPC4 (about 50%), HER-2/neu (in about 65%) and FHIT (found in 70% of cases). Other genes involved are notch1, Akt-2, BRCA2 and COX-2. These proteins are important targets of target therapies for pancreatic cancer.

MCE offers a unique collection of 2713 compounds with identified and potential anti- pancreatic cancer activity. These compounds target K-Ras, p53, HER2, Notch, AKT, etc. MCE anti-pancreatic cancer compound library is a useful tool for anti-pancreatic cancer drugs screening and other related research.

Coagulation, also known as clotting, is the process in which blood changes from a liquid to a solid gel to form a blood clot. Thrombin, which is accurately and evenly generated in the injured part of blood vessels, is a key effector enzyme of the blood coagulation system and participates in many important biological processes, such as platelet activation, fibrinogen conversion to fibrin network, coagulation feedback amplification, etc. At the same time, to avoid the accidental formation of thrombus in the body, there is also an anticoagulant mechanism that inhibits blood coagulation.

Normal coagulation mechanism represents a balance between the pro-coagulant pathway in the injured site and anti-coagulant pathway beyond it. The blood coagulation system may be out of balance during the perioperative period or critical illness, which may lead to thrombosis or excessive bleeding. Therefore, the physiological study of coagulation balance is an important basis for clinical diagnosis and treatment of the abnormal coagulation process.

MCE supplies a unique collection of 973 compounds targeting key proteins in coagulation and anti-coagulation system. MCE Coagulation and Anti-coagulation Compound Library is a useful tool for study the mechanism of coagulation and anticoagulation.

Aging is a complex biological process characterized by functional decline of tissues and organs, structural degeneration, and reduced adaptability and resistance, all of which contribute to an increase in morbidity and mortality caused by multiple chronic diseases, such as Alzheimer's disease, cancer, and diabetes. Many theories, which fall into two main categories: programmed and error theories, have been proposed to explain the process of aging, but neither of them appears to be fully satisfactory. The programmed theories imply that aging relies on specific gene regulation, and the error theories emphasize the internal and environmental damages accumulated to living organisms. The damage theories proposed the nine hallmarks that were generally considered to contribute to the aging process: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient-sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication.

MCE Anti-Aging Compound Library contains 4417 compounds, mainly targeting Sirtuin, mTOR, IGF-1R, AMPK, p53, Telomerase, Mitophagy, Mitochondrial Metabolism, COX, Cytochrome P450, Oxidase, etc. This library is a useful tool for anti-aging research.

Flavonoids are an important class of natural products; particularly, they belong to a class of plant secondary metabolites having a polyphenolic structure, widely found in fruits, vegetables and certain beverages. Flavonoids can be subdivided into different subgroups depending on the carbon of the C ring on which the B ring is attached and the degree of unsaturation and oxidation of the C ring. These subgroups are: flavones, flavonols, flavanones, flavanonols, flavanols or catechins, anthocyanins and chalcones. Flavonoids are now considered as an indispensable component in a variety of nutraceutical, pharmaceutical, medicinal and cosmetic applications. This is attributed to their anti-oxidative, anti-inflammatory, anti-mutagenic and anti-carcinogenic properties coupled with their capacity to modulate key cellular enzyme function. Naturally occurring flavonoids are known to have biological activities for use as drugs, for example, in diseases like cancer, Alzheimer’s disease (AD), atherosclerosis, etc.

MCE offers a unique collection of 519 natural flavonoid compounds which is a useful tool for drug discovery as an important source of lead compounds.

The immune system is a host defense system comprising many biological structures and processes within an organism that protects against disease. To function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, and distinguish them from the organism's own healthy tissue. Inflammation is also the body's attempt at self-protection to remove harmful stimuli and begin the healing process. It’s part of the body's immune response. The immune system recognizes damaged cells, irritants, and pathogens, and inflammation begins the healing process. Inflammatory abnormalities are a large group of disorders that underlie a vast variety of human diseases. The immune system is often involved with inflammatory disorders, demonstrated in both allergic reactions and some myopathies, with many immune system disorders resulting in abnormal inflammation.

MCE designs a unique collection of 5054 compounds that are useful tool for Immunology/Inflammation research or autoimmune inflammatory diseases 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 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.

According to reports, most known kinase inhibitors exert their effects through competitive binding in highly conserved ATP pockets. Although genetic techniques such as RNA interference can inactivate specific genes, most kinases are multi domain proteins, each of which has an independent function. Highly selective inhibitors have higher efficiency than non-selective inhibitors, and the selectivity to the target is at least 100 times higher. Therefore, ensuring the validation of targets with the most selective inhibitors is crucial for a more thorough understanding of the pharmacology of the kinase field. The Highly Selective Inhibitors Library contains 4694 compounds, covering multiple targets and subtypes, such as GPCR protein family, Ion channel, multiple kinases, etc. The Highly Selective Inhibitors Library is an effective tool for screening different phenotypes

Oxidative stress is an imbalance of free radicals and antioxidants in the body, which can lead to cell and tissue damage. Oxidative stress can be responsible for the induction of several diseases, both chronic and degenerative, as well as speeding up body aging process and cause acute pathologies. Antioxidants are a class of compounds able to counteract oxidative stress and mitigate its effects on individuals’ health, gained enormous attention from the biomedical research community. Antioxidants have long been substantial and amenable therapeutic arsenals for multifarious diseases such as AD and cancer.

MCE Antioxidant Compound Library contains 1498 compounds that act as antioxidants for high throughput screening (HTS) and high content screening (HCS). This library is a useful tool for discovery new antioxidants and oxidative stress research.

Lipids are a diverse and ubiquitous group of compounds which have many key biological functions, such as acting as structural components of cell membranes, serving as energy storage sources and participating in signaling pathways. Several studies suggest that bioactive lipids have effects on the treatment of some mental illnesses and metabolic syndrome. For example, DHA and EPA are important for monoaminergic neurotransmission, brain development and synaptic functioning, and are also correlated with a reduced risk of cancer and cardiovascular disease in clinical and animal studies.

MCE supplies a unique collection of 1363 lipid and lipid derivative related compounds including triglycerides, phospholipids, sphingolipids, steroids and their structural analogues or derivatives. MCE lipid compound library can be used for research in bioactive lipids, and high throughput screening (HTS) and high content screening (HCS).

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 3516 compounds with confirmed high oral bioavailability. MCE Orally Active Compound Library is a useful tool for discovering new drugs with oral bioavailability.

Antibacterial agents are a group of materials that fight against pathogenic bacteria. Thus, by killing or reducing the metabolic activity of bacteria, their pathogenic effect in the biological environments will be minimized. The most widely used antibacterial agents exert their effects on bacterial cell wall synthesis, protein synthesis, DNA replication and metabolic pathways. However, resistance to antimicrobial agents has become a major source of morbidity and mortality worldwide. The main mechanisms of resistance are limiting uptake of a drug, modification of a drug target, inactivation of a drug, and active efflux of a drug. Therefore, it is an urgent need to develop new drugs targeted at resistant organisms.

MCE offers a unique collection of 1315 compounds with validated antibacterial activities. MCE antibacterial compound library is an effective tool for drug repurposing screening, combination screening and biological investigation.

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 680 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).

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 1590 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.

Radiation sickness is a general term for various types and degrees of damage (or disease) occurring in the human body after exposure to ionizing radiation. Although small amounts of ionizing radiation can also cause the body to produce free radicals and ROS, causing oxidative stress, resulting in DNA damage and chromosomal aberration. Radioprotector are compounds with radiation protection that can be used to prevent/protect non-tumor cells from the harmful effects of radiation. Radioprotective compounds can prevent the damage of radioactive substances to the human body and reduce the clinical symptoms of various radioactive diseases. In addition, radioprotectors can protect normal cells from damage during radiation therapy. The ideal anti-radiation drug should not affect the sensitivity of tumor cells to radiation therapy while protecting normal cells.

MCE designs a unique collection of 1809 radioprotectors. Radioprotector Library is an effective tool for acute Radiation Syndrome, drug combination research with radiation drugs.

Cancer is a multi-step process which involves initiation, promotion and progression. Chemical carcinogens can alter any of these processes to induce their carcinogenic effects. People are continuously exposed exogenously to varying amounts of chemicals that have been shown to have carcinogenic or mutagenic properties in experimental systems. Exposure can occur exogenously when these agents are present in food, air or water, and also endogenously when they are products of metabolism or pathophysiologic states such as inflammation. The administration of chemical carcinogens is one of the most commonly used methods to induce tumors in several organs in laboratory animals in order to study oncologic diseases of humans. MCE offers a unique collection of 130 chemical carcinogens which have been identified with carcinogenic activity either in humans or in animal models. MCE Tumorigenesis-Related Compound Library is a powerful tool for studying oncologic diseases of humans. Standard opration based on safety data sheet will not cause harm to the body.

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 23000 compounds with confirmed biological activities and clear targets. These compounds include natural products, innovative compounds, approved compounds, and clinical compounds. This library is a useful tool for signal pathway research, drug discovery and drug repurposing, etc.

Bioactive Compound Library Plus, with more powerful screening capability, further complements Bioactive Compound Library (HY-L001) by adding some compounds with low solubility or solution stability (Part B) and some novel, rare or exclusive compounds (Part C) to this library. All those supplementary are supplied in powder form.

Medicine Food Homology (MFH) means that some food themselves are medicines and there is no absolute boundary between them. MFH theory combines the function of food and medicine together scientifically and MFH materials can be used both for food and medicine. Besides nutritional value, MFH materials also have the functions in the prevention and treatment of disease and many other healthcare effects. Food as medicines has many benefits because of their safety while taking drugs will bring inevitable side effect to people. In order to ensure the safe use of functional food, National Health Commission of People's Republic of China made specific provisions on MFH items. More than 100 kinds of widely used MFH materials have been released.

Based on MFH items released by National Health Commission, PRC, MCE carefully designs a unique collection of 1717 Medicine Food Homology Compounds with high safety that can be used for high throughput and high content screening for drug discovery.

Pain is a kind of distressing feeling caused by the stimulation of tissue damage. According to the International Association for the Study of Pain (IASP), pain is defined as ”An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”.

Pain is usually classified according to its location, duration, underlying causes, and intensity. For example, acute and chronic pain, muscle pain, and nerve pain. Pain is the main symptom of most diseases, which seriously affects the quality of life and body function of patients. In the medical treatment of pain, anti-inflammatory drugs and opioid analgesic agents have traditionally been used, but the side effects are serious. In recent years, targeted drugs targeting the ERK/MAPK pathway or other targets have gradually become a research hotspot.

MCE supplies a unique collection of 1930 compounds targeting key proteins in the pain system. MCE Pain-Related Compound Library is a useful tool for pain related research and anti-pain drug development.

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 333 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.

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.

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.

Chinese herbal therapy is an important part of Traditional Chinese Medicine (TCM). It has been used for centuries in China, where herbs are considered fundamental therapy for many acute and chronic conditions. Many studies indicated TCM exerted an overall regulatory effect via multi-component and multi-target network. Active components from Traditional Chinese Medicine possess many medicinal properties such as antioxidant, anti-cancer, and anti-bacterial effects, which makes it an important source of new drugs. Nearly 200 modern medicines have been developed either directly or indirectly from the plants used as medicines in China. For example, artemisinin, used in multidrug resistant malaria, was first isolated from the Chinese herb Artemisia annua L. Today, scientists continue to identify compounds in Chinese herbal remedies that may be useful in the development of new therapeutic agents applicable in Western medicine.

MCE designs a unique collection of 2861 active compounds of Chinese Herbal Medicines. MCE Traditional Chinese Medicine Active Compound Library is a useful tool for discovery new drugs from TCM.

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.

Hepatitis C virus (HCV) is a hepatotropic enveloped positive- strand RNA virus (family Flaviviridae) that infects the parenchymal cells of the liver. HCV infection is a significant public health burden. Globally, an estimated 71 million people have chronic hepatitis C virus infection. A significant number of those who are chronically infected will develop cirrhosis or liver cancer. To date, there is no vaccine against HCV, and combination pegylated alpha interferon (pIFN-) and ribavirin, the main standard-of-care treatment for HCV, is effective in only a subset of patients and is associated with a wide spectrum of toxic side effects and complications. More recently, new therapeutic approaches that target essential components of the HCV life cycle have been developed, including direct-acting antiviral (DAA) that specifically block a viral enzyme or functional protein and host-targeted agents (HTA) that block interactions between host proteins and viral components that are essential to the viral life cycle. However, the genetic diversity of HCV viruses and the stage of liver disease (i.e., cirrhosis) are revealing themselves as obstacles for effective, pan-genotypic treatments. There still exists a need for the discovery and development of new HCV inhibitors. In particular, since the future of HCV therapy will likely consist of a cocktail approach using multiple inhibitors that target different steps of infection, new antivirals targeting all steps of the viral infection cycle.

MCE offers a unique collection of 283 compounds with identified and potential anti-HCV activity. MCE Anti- Hepatitis C Virus Compound Library is a useful tool for discovery new anti-HCV drugs and other anti-infection research.