chemical structure

MCE 5K Scaffold Library consists of 5,000 lead-like compounds. Each compound represents one unique scaffold. All compounds are compatible with Lipinski’s rule (Rule of 5) with multiple characteristics such as calculated good solubility (-3.2 < logP < 5), oral bioavailability (RotB <= 10), drug transportability (PSA < 120). Compounds contained within the library have been screened to remove any inappropriate chemical structures, avoiding “false hits”. The sufficient diverse of compound structure makes this library a powerful tool for drug screening.

Designed to maximize efficiency in hit discovery and optimization, this compound library is built on a foundation of diverse Bemis-Murcko scaffolds, with each scaffold is represented by two specifically derived molecules. This strategy ensures broad chemical space through scaffold diversity while enabling preliminary functional group exploration. This approach provides early structure-activity relationship (SAR) insights for every scaffold, making it a valuable tool for accelerating drug discovery.

In modern medicinal chemistry and chemical biology research, alkyne (-C≡C-) structures play an important role in click chemistry, bioorthogonal labeling, and the construction of functional molecules due to their unique linear geometry and high reactivity. In particular, driven by the development of copper-catalyzed azide-alkyne cycloaddition (CuAAC) and copper-free click reactions (SPAAC), terminal alkyne groups have become important “chemical handles” for building complex biomolecular systems.

The MCE Alkyne Compound Library contains 385 compounds designed for the construction of click chemistry reaction systems and the development of diverse functional molecules. In drug discovery, these structures serve as key reactive sites that can efficiently undergo click reactions with azide groups, enabling modular assembly of PROTAC molecules, construction of ADC linkers, and rapid synthesis of bioorthogonal labeling probes. In addition, alkyne groups exhibit high stability, mild reaction conditions, and excellent biocompatibility, allowing them to maintain reactivity in complex biological environments. This contributes to improved efficiency and controllability in drug development, making them indispensable chemical building blocks in modern drug design and functional molecular engineering.

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

MCE provides a unique collection of 45 natural product-like compounds that are structurally like Steroids, Tannins, Flavonoids, Quinones, Isoquinolines, etc. This library is an important source of lead compounds for drug discovery.

At the forefront of innovative drug discovery, every medicinal chemist faces the challenge of rapidly identifying high-quality hit compounds from vast repositories of chemical resources.

The MCE Natural Product Diversity Scaffold Library is the result of a streamlined optimization process built upon our existing natural product collection. Adhering to the rigorous selection principle of "retaining only one representative compound per BMS scaffold", we have concentrated the diversity of thousands of compounds into a high-value, low-redundancy core set containing 2,285 compounds. All compounds are derived from natural sources, inheriting their inherent advantages of structural complexity and drug-likeness. By eliminating redundancy, the library size is significantly reduced without any compromise to chemical diversity. This approach effectively lowers the cost and time required for primary screening while simplifying downstream data analysis and structure-activity relationship (SAR) studies.

Liposomes are spherical or multilayered spherical vesicles formed by the self-assembly of diacyl chain phospholipids (lipid bilayers) in aqueous solutions, which can be made from natural or synthetic phospholipids and exhibit good biocompatibility and low toxicity. They can serve as delivery carriers for various bioactive substances (such as drugs, proteins, nucleic acids, etc.) and are widely used in biomedical and chemical research. The main advantages of liposomes include 1) Protective effect: Their bilayer structure can protect encapsulated molecules from enzymatic degradation, oxidation, and other influences, extending stability and activity; 2) Active targeting: Surface modifications enable active targeting, enhancing the concentration of drugs or molecules in specific tissues or cells; 3) Customizability: The composition and structure of liposomes can be adjusted according to needs, such as altering phospholipid types or adding targeting ligands. These properties make liposomes highly valuable in developing novel drug delivery systems, serving as nucleic acid carriers for gene transfection, studying cellular uptake mechanisms and drug release kinetics, as well as developing functional food additives to improve the bioavailability of nutritional components.

MCE contains 190 liposome compounds, which is a good tool for lipidomic-related studies.

The discovery of hit molecule is a cornerstone of drug development. Among the diverse tools available, DNA-encoded libraries have emerged a revolutionary platform for high-throughput screening. Compared with traditional HTS, DEL features shorter screening processes, lower costs, simpler assays, and larger library capacities.

DEL Construction utilizes split-and-pool synthesis, a combinatorial chemistry approach that involves iterative splitting, reaction, and pooling. This strategy enables rapid, exponential assembly of fragments in minimal steps without the need for individual compound synthesis andassoicicated isolation or purification steps, thus greatly reducing overall costs. The technology enables simultaneous affinity screeningof massive compound collections to target proteins in a single step. By coupling chemical structures with unique DNA barcodes, each compound is tagged with a distinct DNA sequence for convenient tracking and decoding.DELs readily enable the construction and efficient screening of libraries containing millions to billions of compounds. As a result, DEL screening combines the dual advantages of high efficiency and low cost, making DEL a transformative technology in modern drug discovery.

The DEL kit consists of 50 independent libraries with a total scale of 100 billion compounds. It is constructed through stepwise combinatorial chemistry strategies involving 2-, 3-, and 4-round synthesis. By employing diverse scaffolds and flexible linking strategies, it encompasses various ring systems, linear frameworks, and heterocyclic structures. Screening can be achieved solely through affinity, independent of target-specific activity detection methods. This library is suitable for DEL screening against a wide range of targets.

Fragment-based drug discovery (FBDD) is well suited for discovering both drug leads and chemical probes of protein function. 3-dimensionality (3D) diversity is pivotal because the molecular shape is one of the most important factors in molecular recognition by a biomolecule. There is a developing appreciation that 3D fragments could offer opportunities that are not provided by 2D fragments.

MCE 3D Diverse Fragment Library consists of 5,400 non-flat fragment-like molecules (average Fsp3 value 0.58). More than 4,700 fragment compounds contain at least one chiral center in the structure. The key concepts that underlie the library design were 3D shape, structural diversity, reactive functionality and fragment-like. This 3D Diverse Fragment Library brings higher fragment hit optimization and increases the likelihood to find innovative hits in FBDD.

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

MCE 10K Natural Product-like Compound Library consists of 10,000 natural product-like compounds. Each compound has scaffold of natural products or Tanimoto coefficient >0.6 with natural products. The natural-likeness scoring of these compounds is >-2. What’s more, compounds in the library are drug-like and readily available for re-supply, making it a powerful tool for new drug research and development. It can be widely applied in high-throughput screening (HTS) and high-content screening (HCS).

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

MCE 5K Natural Product-like Compound Library consists of 5,000 natural product-like compounds. Each compound has scaffold of natural products or Tanimoto coefficient >0.6 with natural products. The natural-likeness scoring of these compounds is >-2. What’s more, compounds in the library are drug-like and readily available for re-supply, making it a powerful tool for new drug research and development. It can be widely applied in high-throughput screening (HTS) and high-content screening (HCS).

Macrocyclic compounds (≥12-atom cyclic small molecules/peptides) have unique physicochemical properties. They form preorganized conformations with high binding affinity/selectivity, target traditional small-molecule-inaccessible proteins, and bridge small-molecule drugs and biological agents. As key protein phosphorylation enzymes, kinases are linked to tumors, COPD, etc., and are critical therapeutic targets. Traditional small-molecule kinase inhibitors lack selectivity, causing off-target toxicity, low bioavailability, and acquired resistance. Macrocycles’ semi-rigid structure restricts conformations, boosts binding selectivity, optimizes pharmacokinetics, and makes macrocyclization a core kinase inhibitor optimization strategy.

Thousands of bioactive macrocycles were curated from ChEMBL. Via Transformer, macrocyclization was converted into a chemical language translation task, enabling end-to-end macrocycle generation from linear precursors with simplified inputs. Macformer achieves efficient, automated linear molecule macrocyclization via deep learning; generated macrocycles have diversity, novelty, biocompatibility, and cover broader chemical space.

MCE collected thousands of marketed/clinical kinase inhibitors, using their fragments for macrocyclization to generate derivatives. After evaluating synthetic accessibility and physicochemical properties, a million-scale virtual macrocyclic library was built for kinase-related virtual and AI-driven screening.

Macrocyclic compounds (≥12-atom cyclic small molecules/peptides) have unique physicochemical properties. They form preorganized conformations with high binding affinity/selectivity, target traditional small-molecule-inaccessible proteins, and bridge small-molecule drugs and biological agents. As key protein phosphorylation enzymes, kinases are linked to tumors, COPD, etc., and are critical therapeutic targets. Traditional small-molecule kinase inhibitors lack selectivity, causing off-target toxicity, low bioavailability, and acquired resistance. Macrocycles’ semi-rigid structure restricts conformations, boosts binding selectivity, optimizes pharmacokinetics, and makes macrocyclization a core kinase inhibitor optimization strategy.

Thousands of bioactive macrocycles were curated from ChEMBL. Via Transformer, macrocyclization was converted into a chemical language translation task, enabling end-to-end macrocycle generation from linear precursors with simplified inputs. Macformer achieves efficient, automated linear molecule macrocyclization via deep learning; generated macrocycles have diversity, novelty, biocompatibility, and cover broader chemical space.

MCE collected thousands of marketed/clinical kinase inhibitors, using their fragments for macrocyclization to generate derivatives. After evaluating synthetic accessibility and physicochemical properties, a million-scale virtual macrocyclic library was built for kinase-related virtual and AI-driven screening.

Sulfonyl fluoride (-SO₂F) overcomes the poor target selectivity of traditional covalent warheads that rely heavily on cysteine. With high stability and tunable electrophilicity under physiological conditions, it targets multiple nucleophilic residues including Lys, Tyr, Ser and His, offering expanded druggable space, lower off-target risks and prolonged efficacy. It is widely used in covalent inhibitors, molecular glues, PROTACs and chemical probes.

MCE has built a highly diverse sulfonyl fluoride fragment library with 1,162 structurally diverse, drug-like fragments. Designed for balanced reactivity, stability and compatibility, these molecules feature tunable electrophilicity, simple scaffolds and high derivatization potential. Combined with SuFEx click chemistry, the library enables efficient modular modification and rapid structure optimization.

Ideal for targeting non-cysteine residues, this library improves covalent screening and probe development efficiency, serving as a precise tool for early-stage covalent drug discovery and chemical biology research.

Polysaccharides are long chains of carbohydrate molecules, consisting of multiple smaller monosaccharides. Polysaccharides are found mainly in natural sources such as plants, microorganisms, algae and animals. Polysaccharides have a large number of active functional groups, different chemical compositions and different molecular weight ranges, which determines their diversity in nature and structure. Also in the field of medical research, polysaccharides act as a class of functional compounds and thus play a role. For example, nanocarrier construction, immunomodulation and vaccine development, new strategies for antitumor therapy, tissue regeneration engineering applications and disease diagnosis. With the advancement of glycomics and synthetic biotechnology, human beings are moving from “knowing polysaccharides” to “designing polysaccharides”, which will provide innovative solutions for materials science, precision medicine and sustainable development.

MCE offers 67 polysaccharides that can be used in biomedical studies.

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 63 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.

The RNA-targeted bioactive compound library is a high-quality collection of small molecules specifically designed and curated to target RNA structures and functions. It is widely applied in cutting-edge drug discovery and life science research. Unlike traditional strategies that focus on protein targets, RNA-targeted compounds can directly modulate various functional RNA molecules by influencing their splicing, translation, stability, or structural conformation, thereby enabling precise intervention in key biological processes. In the field of drug development, these compounds provide a novel approach to addressing previously “undruggable” targets and have demonstrated significant potential in areas such as oncology, antiviral therapies, and neurodegenerative diseases. For example, by targeting disease-associated RNA structural domains or regulating the aberrant expression of non-coding RNAs, these compounds can effectively inhibit disease progression or restore normal cellular function. In mechanistic studies, RNA-targeted compounds serve as valuable chemical biology tools to elucidate the roles of RNA in gene expression regulation, cellular signaling pathways, and disease development.

The MCE RNA-targeted bioactive compound library contains 857 compounds, sourced from databases such as TargetRX Atlas and R-BIND. The library features excellent structural diversity and biological activity, making it suitable for high-throughput screening (HTS), target validation, phenotypic screening, and lead compound discovery. It represents a valuable resource for RNA-related research and innovative drug development.

19F-NMR has proved to be a detection mode in fragment-based drug discovery (FBDD) for studies of protein structure and interactions. 19F shows high sensitivity for NMR detection, and the exquisite sensitivity of 19F chemical shifts and linewidths to ligand binding all make it a valuable approach in FBDD.F (Fluorine) -Fragments can be used for 19F-NMR detection after binding to target proteins, and can be used as an effective 19F-NMR tool for FBDD.

MCE designs a unique collection of 5,134 F-fragments, all of which obey a heuristic rule called the “Rule of Three (RO3)”, in which molecular weight ≤300 Da, the number of hydrogen bond donors (H-donors) ≤3, the number of hydrogen bond acceptors (H-acceptors) is ≤3 and cLogP is ≤3. This F-fragments library is an important source of lead-like drugs.

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 559 compounds with validated antifungal activities. MCE antifungal compound library is an effective tool for drug repurposing screening, combination screening and biological investigation.

Boronic acid and boronic ester represent a relatively novel and promising chemical structure in drug design. Boronic acid exists in an sp²-hybridized state, possessing an empty p-orbital that can act as a Lewis acid to accept lone pairs from heteroatoms (O, N, or S). This Lewis acidity enables it to form reversible covalent bonds with amino acid residues such as lysine, serine, threonine, and histidine. Currently, five FDA-approved drugs containing boronic acid or boronic ester predominantly involve such covalent binding mechanisms in their interactions with target proteins. Furthermore, boronic acid can serve as a bioisostere for carboxylic acids, phosphates, and phenolic groups, utilized to improve pharmacokinetic properties and enhance drug efficacy.

To date, five boron-containing drugs have been approved by the FDA. The unique properties of boronic acids and boronic esters confer significant potential in drug design, with applications spanning cancer therapy (e.g., multiple myeloma), anti-infectives (e.g., fungal infections, tuberculosis), anti-inflammatory treatments (e.g., atopic dermatitis), antibacterial agents (e.g., carbapenem-resistant bacterial infections), and Reactive Oxygen Species (ROS)-responsive prodrugs, among others. The MCE Boronic Acid/Boronic Ester Fragment Library, which contains 1,488 compounds, serves as a valuable tool for the development of boron-containing drugs.

DEL technology enables the simultaneous screening of millions or billions of compounds in a single tube by covalently linking each small molecule with a unique DNA sequence. Traditional DEL screening primarily focuses on identifying non-covalent binding molecules, where interactions with the target are reversible. In contrast, DNA‑encoded covalent library is an ultra‑high‑throughput screening library developed on the basis of conventional DNA‑encoded library technology. It incorporates controllable electrophilic covalent warheads capable of forming irreversible covalent bonds with amino acid residues at the active sites of target proteins, including Cys, Lys, Ser, Tyr, and others. This covalent binding enhances binding affinity, prolongs residence time at the target site, and has the potential to overcome challenges associated with traditional non-covalent inhibitors, such as drug resistance or off-target effects.

Each compound in the library contains both a binding domain and an electrophilic warhead. It first recognizes and binds to the target through non covalent interactions, and then forms a stable covalent bond with key amino acid residues to achieve irreversible inhibition. This library is specifically designed for the discovery of potent, long lasting, and highly selective covalent inhibitors, particularly for undruggable targets such as kinases, GPCRs, proteases, and mutant oncoproteins. Each molecule is uniquely labeled with a DNA barcode for molecular identification and sequencing decoding.

This library is an advanced and highly diverse collection, consists of 35 independent sub-libraries with a total scaleof 14 million compounds, It incorporates over 14 experimentally validated covalent warheads capable of targeting cysteine, lysine, arginine, aspartic acid and glutamic acid. This library is constructed with diverse drug like core scaffolds and integrated controllable covalent warheads, it features structural diversity, reaction spec

Cyclic peptide library have advantages such as high affinity, high selectivity, and suitability for targeting protein–protein interactions. Through DEL synthesis technology, the library size can achieve hundreds of millions. DEL cyclic peptide library have advantages like low cost andhigh screeing efficiency, making them valuable for discovering lead compounds against challenging drug targets.

This cyclic peptide library is constructed with unnatural amino acids as building block, synthesized through DNA-compatible chemical reactions. Each cyclic peptide consist of six amino acids and constrained conformations such as side-chain cross-linking, disulfide bonds, and macrocyclization. These cyclic peptides exhibit significantly improved stability and druggability compared with linear peptides, filling the gap between small molecules and macromolecular biologics. Each cyclic peptide is uniquely conjugated to a DNA barcode sequence for molecular identification and sequencing decoding.

MCE’s cyclic peptide library has8 independent sub-libraries, with a total molecular diversity of 1.2 billion. It is constructed via multi-round combinatorial assembly of building blocks and diverse cyclization strategies, facilitating the discovery of cyclic peptide leads for undruggable targets.

KRAS (Kirsten Rat Sarcoma Viral Oncogene Homolog) is one of the most important oncogenic driver genes in oncology, with high mutation frequencies in pancreatic cancer, non‑small cell lung cancer, and colorectal cancer. For a long time, KRAS was considered "undruggable" due to the lack of suitable small‑molecule binding pockets on its protein surface. In recent years, with the discovery of the switch‑II pocket and the successful approval of KRAS G12C inhibitors, KRAS‑targeted research has achieved groundbreaking progress, which has also spurred a wave of development targeting non‑G12C mutants such as G12D and G12V, as well as upstream and downstream regulatory factors including SOS1 and SHP2.

MCE KRAS Targeted Compound Library contains 32 small‑molecule compounds targeting the KRAS, serving as high‑quality research tools for mechanistic studies of KRAS‑mutant tumors, combination therapy development, resistance mechanism exploration, and high‑throughput drug screening, thereby providing robust support for KRAS‑targeted drug discovery.

Cell death is a core biological process that maintains homeostasis in multicellular organisms, playing a dual role in life activities. On one hand, cell death participates in physiological processes such as cell renewal and damage repair through precise regulation; on the other hand, it actively eliminates damaged, infected, or cancerous cells, thereby blocking pathological progression and preserving organism health. Cell death not only ensures the normal development and growth regulation of organisms but is also closely associated with the occurrence and development of various diseases. Numerous studies have shown that specific types of programmed cell death play critical roles in disease progression, providing an important theoretical basis for developing novel therapeutic strategies by regulating cell death pathways.

MCE offers 23 types of commonly used cell death inhibitors, such as apoptosis, ferroptosis, pyroptosis, and cuproptosis, suitable for use as positive controls in the study of novel cell death mechanisms.

Amino acids are indispensable building blocks for life activities and are widely involved in key biological processes such as cell signal transduction, energy metabolism, gene expression regulation, and neurotransmitter synthesis. As components of proteins, 20 kinds of amino acids make up over one million kinds of proteins in the human body. These amino acids can be classified into nine types of "essential amino acids" that the human body cannot synthesize on its own and must obtain from food, as well as eleven types of "non-essential amino acids" that the human body can synthesize on its own.

MCE offers 20 kinds of amino acids provided which can be applied in research fields such as the study of amino acid metabolic processes, metabolite identification, food/cosmetic ingredient research, and the development of nutritional supplements.

Epigenetics involves heritable phenotypic changes that occur without alterations to the underlying DNA sequence. Key mechanisms include DNA methylation, histone modifications, and regulation by small non-coding RNAs such as microRNAs. By modifying DNA, histones, or RNA—while leaving their primary sequences intact—these processes influence molecular function and regulation, thereby playing critical roles in cellular differentiation, embryonic development, gene expression control, aging, and diseases such as cancer.

MCE provide a unique collection of 297 epigenetics-related compounds. For each regulatory target and its subtype, 3 to 5 highly specific representative compounds have been retained, which can be used in epigenetic and related disease research.

Epigenetics refers to changes in phenotype that are not rooted in DNA sequence. Many types of epigenetic processes have been identified, including DNA methylation, alteration in the structure of histone proteins and gene regulation by small noncoding microRNAs. Modification of DNA, protein, or RNA, resulting in changes to the function and/or regulation of these molecules, without altering their primary sequences, reveals the complexities of cellular differentiation, embryology, the regulation of gene expression, aging, cancer, and other diseases.

MCE provide a unique collection of 1,970 epigenetics-related compounds that can be used in the research of the related diseases.

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

MCE 50K Diversity Library consists of 50,000 lead-like compounds with multiple characteristics such as calculated good solubility (-3.2 < logP < 5), oral bioavailability (RotB <= 10), drug transportability (PSA < 120). These compounds were selected by dissimilarity search with an average Tanimoto Coefficient of 0.52. There are 36,857 unique scaffolds and each scaffold 1 to 7 compounds. What’s more, compounds with the same scaffold have as many functional groups as possible, which make abundant chemical spaces. This exceptionally diverse library is highly recommended for random screening against new as well as popular targets based its novel, diverse scaffolds, abundant chemical spaces and the convenience for subsequent modification.

The TCA cycle (tricarboxylic acid cycle)—is also known as the Krebs cycle or the citric acid cycle (CAC). The TCA cycle is a series of chemical reactions that release stored energy through the oxidation of acetyl-CoA in carbohydrates, fats, and proteins.

For decades, the TCA cycle has been considered as the central pathway for cell oxidative phosphorylation to produce energy and biosynthesis. Research shows that TCA cycle is associated with many diseases, especially cancer. In colon carcinoma, liver cancer and other cancers, there are mutations that lead to the imbalance of TCA cycle metabolites, indicating that TCA cycle may be related to the occurrence of cancer. Understanding the role and molecular mechanism of TCA cycle in inhibiting or promoting cancer progression will promote the development of new metabolite-based cancer treatment methods in the future.

MCE supplies a unique collection of 26 key intermediates of the TCA cycle, which can be utilized for TCA-related research and metabolomics identification studies.

Plant hormones are natural signaling molecules synthesized by plants themselves, serving as crucial chemical messengers that exert physiological effects on plants at extremely low concentrations. They coordinate cellular growth, division, differentiation, and organ formation, helping plants adapt to environmental changes. Major categories include abscisic acid, auxins, gibberellins, cytokinins, ethylene, and brassinosteroids, among others.

MCE has included 45 plant hormones, which can be used for identification in plant metabolomics and related botanical research.

Nucleoside and nucleotide analogues are synthetic, chemically modified compounds that have been developed to mimic their physiological counterparts in order to exploit cellular metabolism and subsequently be incorporated into DNA and RNA to inhibit cellular division and viral replication. In addition to their incorporation into nucleic acids, nucleoside and nucleotide analogues can interact with and inhibit essential enzymes such as human and viral polymerases (that is, DNA-dependent DNA polymerases, RNA-dependent DNA polymerases or RNA-dependent RNA polymerases), kinases, ribonucleotide reductase, DNA methyltransferases, purine and pyrimidine nucleoside phosphorylase and thymidylate synthase. These actions of nucleoside and nucleotide analogues have potential therapeutic benefits — for example, in the inhibition of cancer cell growth, the inhibition of viral replication as well as other indications.

MCE offers a unique collection of 575 nucleotide compounds including nucleotide, nucleoside and their structural analogues. MCE Nucleotide Compound Library is a useful tool to discover anti-cancer and antiviral drugs for high throughput screening (HTS) and high content screening (HCS).

Flavors and fragrances serve as indispensable enhancing elements in modern industries, playing multidimensional roles in the fields of food, cosmetics, and pharmaceutical development. In the food industry, flavors and fragrances are not only used to compensate for flavor loss during processing but also to create novel sensory experiences and enhance product appeal. Natural flavors such as vanilla and citrus oils impart rich, layered aromas to foods, while synthetic flavors can precisely replicate specific tastes, meeting the demands of standardized production and extending the flavor stability of food products. In the cosmetics sector, flavors and fragrances are key to emotional design. They enhance product recognition and elevate the pleasure of use through pleasant scents. In pharmaceutical development, the application of flavors and fragrances focuses on improving compliance. Especially in formulations such as oral liquids and chewable tablets, the addition of mint, fruit, and other flavoring components effectively masks the bitter or irritating taste of medications, increasing patient acceptance. Additionally, some natural flavors may themselves possess auxiliary therapeutic benefits.

MCE contains 496 kinds of flavors and fragrances, which can be used in fields such as food, cosmetics and drug development.

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 144 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.

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 1,274 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).

Glycosides are compounds in which a sugar group is bonded through its anomeric carbon to another group via a glycosidic bond. Many biologically active compounds are glycosides. Glycosides comprise several important classes of compounds such as hormones, sweeteners, alkaloids, flavonoids, antibiotics, etc. The glycosidic residue can be crucial for their activity or can only improve pharmacokinetic parameters. Glycosides, which exhibit anti-inflammatory, anti-infection, anti-cancer and anti-oxidative properties, play numerous important roles in living organisms, such as streptomycin, as an aminoglycoside antibiotic, has anti-infection activity. Anthracyclines possess good antibacterial and anti-cancer activities.

MCE Glycoside Compound Library contains a unique collection of 896 glycoside compounds and is a useful tool to discovery glycoside drugs.

Chinese Baijiu is one of the oldest alcoholic beverages in the world, with a history of over 2,000 years. It can be classified into 12 aroma types based on its fragrance and flavor characteristics. The specific flavor profile of Baijiu is determined by the composition and concentration of certain compounds. These trace compounds, present in low concentrations yet rich in esters, alcohols, acids, lactones, aldehydes, ketones, acetals, alkenes, and others, significantly influence the flavor of Baijiu. Additionally, some active components in Baijiu possess antioxidant properties, and moderate consumption may help reduce the risk of cardiovascular diseases, dementia, and insulin resistance. Therefore, studying the chemical composition of Baijiu is crucial for promoting its fermentation process and enhancing its flavor and quality.

MCE has compiled included 669 Chinese Baijiu components, which can be used for drug development, Baijiu fermentation, and research related to Baijiu flavor and aroma.

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

MCE offers a unique collection of 451 macrocyclic compounds which can be used for drug discovery for high throughput screening (HTS) and high content screening (HCS). MCE Macrocyclic Compound Library is a useful tool for discovering new drugs, especially for “undruggable” targets and protein–protein interactions.

In the progression of various diseases, metabolic reprogramming has emerged as a key hallmark. Lactate, as an important metabolic signaling molecule, is widely involved in tumorigenesis, immune regulation, and inflammatory responses. Particularly within the tumor microenvironment, the abnormal accumulation of lactate not only affects cellular energy metabolism but also promotes disease progression by modulating immune cell functions and mediating protein lactylation, thereby participating in epigenetic regulation and signaling networks. Therefore, systematic investigation of lactate metabolic pathways and their associated metabolites is of great significance for understanding disease mechanisms and developing novel therapeutic strategies.

The MCE lactic acid metabolite compound library contains 63 compounds and is constructed around key metabolic pathways involving lactate production, transport, and utilization. This library systematically includes core intermediates from glycolysis, the tricarboxylic acid (TCA) cycle, and the lactate cycle. Focusing on disease-associated metabolic reprogramming, it is suitable for research in oncology, inflammation, and metabolic disorders. The library can be used to elucidate the roles of lactate in tumor microenvironment regulation, immune evasion, and epigenetic modifications (such as protein lactylation). In addition, it provides high-quality small-molecule resources for drug screening, facilitating the discovery of potential modulators targeting key enzymes (such as LDH) or transporters (such as MCTs) involved in lactate metabolism.

Protein lactylation, an emerging post-translational modification identified in recent years, plays a critical role in linking cellular metabolic reprogramming, epigenetic regulation, and signaling networks. Based on a systematic framework encompassing lactate metabolism, lactylation, and downstream signaling pathways, this compound library comprehensively targets multiple regulatory layers, including histone modification enzymes (such as p300 and HDACs), key glycolytic enzymes (such as PKM2, LDHA, and GAPDH), transcriptional regulators (such as STAT3, HMGB1, and p53), as well as central signaling pathway nodes including HIF-1α, NF-κB, and PI3K-AKT-mTOR. This integrated design enables a comprehensive representation of the regulatory roles of lactylation across the “metabolism–epigenetics–signaling” axis.

MCE has assembled a collection of 5,946 known bioactive compounds and potential functional molecules, making this library suitable for a wide range of applications, including high-throughput drug screening, inhibitor identification, and mechanistic studies. It can be used to systematically evaluate the functional roles of lactylation in biological processes such as tumor metabolism, immune regulation, and inflammatory responses, and to efficiently identify small-molecule candidates with regulatory potential, thereby facilitating the development of innovative therapeutics targeting the interplay between metabolism and epigenetic regulation.

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 3,402 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.

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

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

MCE Anti-diabetic Compound Library owns a unique collection of 1,125 compounds, which mainly target SGLT, PPAR, DPP-4, AMPK, Dipeptidyl Peptidase, Glucagon Receptor, etc. This library is a useful tool for discovery anti-diabetes drugs.

Peptides, composed of amino acids, serve as crucial building blocks for proteins and have gained significant attention in drug development over the past decade. The advancements in production, modification, and analytical technologies have led to a surge in the potential applications of peptides in medicine. Peptides offer a number of advantages over small molecule drugs, including: greater target specificity and efficacy, more predictable metabolic profiles, easier delivery to where they are needed in the body, and fewer side effects. Peptides are increasingly appearing in all branches of medicine as components of innovative drugs, imaging agents, diagnostic agents, and other complex drugs such as peptide-drug conjugates. To date, more than 80 peptide drugs have been approved to treat a variety of diseases, including microbial infections, obesity, anti-diabetes, and cancer, as well as to develop cell targeting platforms and improve cell penetration properties.

MCE designs a unique collection of 832 peptide compounds. HY-L105S is a peptide compound library that can be provided with solution form based on HY-L105, and can be applied to peptides-based drug development.