Small molecules

CRBN, namely cereblon, is the substrate recognition subunit of the E3 ubiquitin ligase complex in the ubiquitin-proteasome system. A CRBN ligand library refers to a collection of numerous fragments that can specifically bind to the CRBN protein.

These ligands are mostly designed based on validated CRBN-binding warheads and modified through AI-driven molecular generation optimization systems. They not only include classic lenalidomide-derived structures but also cover novel non-lenalidomide scaffolds. After drug-likeness filtering, these ligands exhibit structural diversity and favorable druggable properties. They can be further optimized and modified to facilitate the development of novel molecular glue degraders, accelerate the discovery of molecular glues that induce interactions between CRBN and new substrate proteins, and enable the exploration of novel CRBN substrates for identifying previously unknown CRBN-binding proteins.

MCE compiles 122 fragments that can specifically bind to the CRBN protein, with molecular weights ranging from 200 to 500. Compounds developed based on the library ligands target multiple disease targets such as cancer and autoimmune diseases, further advancing the development of Molecular Glues and PROTACs therapeutic agents.

Owing to the widespread transmission and frequent mutation of viral diseases, as well as the continuous emergence of new viruses and drug-resistant strains, antiviral drug development is facing increasingly stringent requirements. Antiviral compound libraries serve as important tools for drug screening, mechanism research and development, enabling the discovery and investigation of various antiviral drugs.

These compounds act through diverse antiviral mechanisms, targeting key steps in viral replication, assembly and invasion. They exert antiviral effects by inhibiting viral nucleic acid synthesis, blocking viral protein processing, and preventing viral binding to host cells. This library covers various types of antiviral compounds, including nucleosides, non-nucleosides, protease inhibitors and integrase inhibitors. It supports research on influenza virus, herpes virus, hepatitis virus, emerging respiratory viruses and other pathogens, and enables high-throughput screening of novel antiviral candidates to rapidly identify potential active compounds against diverse viruses. It also facilitates mechanistic studies to elucidate drug-target interactions and viral resistance mechanisms, and supports the screening of effective compounds against mutant strains for research on viral variation and drug resistance.

This antiviral library consists of 6,804 compounds with lead-like physicochemical properties. The core sources of the compounds include analogs of known antiviral molecues with a similarity score ≥ 0.6. MCE has collected more than 1450 antiviral molecules. As a small-molecule collection with both activity potential and structural modifiability, it provides strong support for antiviral drug research and development.

Protein ubiquitination is an enzymatic post-translational modification in which an ubiquitin protein is attached to a substrate protein. Ubiquitination involves three main steps: activation, conjugation, and ligation, performed by ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s), and ubiquitin ligases (E3s), respectively. Ubiquitination affects cellular processes such as apoptosis, cell cycle, DNA damage repair, and membrane transportation, etc. by regulating the degradation of proteins (via the proteasome and lysosome), altering the cellular localization of proteins, affecting proteins activity, and promoting or preventing protein-protein interactions. Deregulation of ubiquitin pathway leads to many diseases such as neurodegeneration, cancer, infection and immunity, etc.

MCE offers a unique collection of 507 small molecule modulators with biological activity used for ubiquitination research. Compounds in this library target the key enzymes in ubiquitin pathway. MCE Ubiquitination Compound Library is a useful tool for the research of ubiquitination regulation and the corresponding diseases.

Metabolomics, positioned as the systemic characterization of small-molecule metabolites within biological systems, has emerged as an indispensable analytical platform in both fundamental research and translational applications across plant sciences, microbial biotechnology, and biomedical investigations. Functioning as a critical component in multi-omics integration, this discipline deciphers the intricate molecular networks operating downstream of genomic, transcriptomic, and proteomic regulation, thereby capturing the dynamic biochemical phenotype closest to organismal functionality. The metabolome, comprising endogenous compounds with molecular weights typically below 1500 Da, serves as the functional readout of cellular processes and environmental interactions, where perturbations in metabolic networks are frequently implicated in disease pathogenesis. Such unique attributes have propelled metabolomics into a pivotal role in pharmacological research, particularly in target deconvolution, pharmacodynamic assessment, and mechanistic elucidation of pathological processes.

MCE can provide 6,077 mass spectrometry human metabolites that can be used for metabolite identification and quantification, functional cell detection and phenotypic screening of mass spectrometry.

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 282 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.

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 5,121 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).

Proteolysis-targeting chimera (PROTAC) has been developed to be a useful technology for targeted protein degradation. PROTACs consist of a ligand for E3 ligase (E3 ligase binder), a linker and a ligand (mostly small-molecule inhibitor) for protein of interest（target binder）. Upon binding to the target protein, the PROTACs can recruit E3 for target protein ubiquitination, which is subjected to proteasome-mediated degradation. Therefore, PROTACs execute their functions by degrading the target proteins rather than inhibiting them, which has a great superiority in overcoming resistance caused by target mutation or overexpression. To date, PROTAC technology has been applied to a variety of targets, including AR, ER, BTK, BET, and BCR-ABL to overcome resistance.

MCE carefully prepared a unique collection of 128 ligands for target proteins, which have been reported to be used in PROTAC design. MCE Target Protein Ligand Library is a useful tool for PROTAC development.

Gastric Cancer (GC) is one of the most common malignant tumors in the world, ranking fourth in mortality rate globally. Because the early symptoms of stomach neoplasm are usually not obvious, are diagnosed with gastric cancer at terminal stage, and the relative survival rate within 5 years is very low. With the further understanding of the molecular characteristics of stomach neoplasm, many therapeutic targets for gastric cancer have been identified, and molecular targeted therapies such as CTLA-4, HER2 and immune checkpoint inhibitors have made rapid progress. Although survival rates for patients with gastric neoplasm have improved over the past few decades, the prognosis is still worrying. Therefore, there is an urgent need for new drugs to treat gastric cancer.

MCE designs a unique collection of 1,203 small molecules with definite or potential anti-gastric cancer activity, which is an important tool for studying the pathological mechanism of stomach neoplasm and developing drugs for stomach neoplasm.

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 1,182 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.

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

The biology of exosomes in disease is still emerging, and the number of studies addressing their utility in the diagnosis and treatment of various pathologies has increased substantially. MCE supplies a unique collection of 58 compounds with the activity of inhibiting or stimulating exsomes secretion/biosynthesis. MCE Exosomes Compound Library is a useful tool for exsomes research.

Mechanoreceptors convert different stimuli from the outside into electrical signals, enabling us to quickly respond to our environment. Mechanoreceptors are distributed throughout the body, including in the skin, tendons, muscles, joint capsules and viscera. In addition to the channels of TRP and Piezo mentioned in the Nobel Prize, there are also targets such as KCNK, ENaC and ASIC2, which play an important role in the environment perception and homeostasis of living organisms.

MCE offers a unique collection of 391 compounds related to mechanoreceptors, which targeting different mechanoreceptors, such as TRP, Piezo, KCNK, ENaC, etc. MCE mechanoreceptors compound library is a powerful tool for studying mechanoreceptors and life perception.

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 3,728 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.

Natural products are small-molecule compounds produced in nature, derived from animals, plants, and microorganisms, including both primary and secondary metabolites. With their structural diversity and favorable biological activities, natural products have long been an important source for drug discovery. Traditional natural product research has often focused on isolating single active components, whereas metabolomics emphasizes a holistic approach—comprehensively detecting all metabolites in a sample and systematically capturing both known and unknown constituents. Consequently, mass spectrometry‑based metabolomics databases have become a key technological support for screening known components and identifying unknown compounds from natural sources.

MCE Mass Spectrometry Natural Product Library contains 4,412 natural products, covering multiple structural classes, including sugars and glycosides, phenylpropanoids, quinones, flavonoids, terpenoids, etc. All compounds have undergone rigorous quality control by LC/MS and other analytical methods, and can serve as high‑purity reference standards for metabolite identification.