LC/MS

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.

Environmental pollution refers to the process where human activities release harmful chemicals or energy (such as industrial waste, pesticides, and plastic particles) into the natural environment at a rate that exceeds the ecosystem's capacity for self-purification, leading to deterioration in the composition or state of the atmosphere, water bodies, and soil. Environmental pollution is not only a direct threat to biodiversity but also ultimately impacts human health through the bioaccumulation effect of the food chain. Therefore, the accurate identification and dynamic monitoring of pollutants constitute the scientific cornerstone for formulating environmental policies, assessing ecological risks, and promoting green chemistry transformation.

MCE features a collection of 296 environmental pollutants, covering categories such as air pollutants, water pollutants, and pesticides, for research in the field of environmental chemistry.

MCE Classic FDA-Approved Drug Library features a curated selection of marketed drugs that have achieved the highest prescription volumes and greatest clinical impact in global practice since 2006. The collection covers eight major therapeutic areas, including cardiovascular diseases, oncology, metabolic disorders, infectious diseases, central nervous system disorders, respiratory diseases, digestive system diseases, and immunological conditions. All compounds have been validated through long‑term clinical use and possess well‑defined molecular targets, well‑established pharmacokinetic properties, quantifiable efficacy endpoints, and comprehensive toxicological safety profiles.

The library currently contains 167 representative drugs and is designed to serve as an efficient tool for drug repurposing, phenotypic screening, mechanism‑of‑action studies, and combination therapy strategy development.

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 82 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.

Built on druggable heterocyclic backbones with tunable electrophilic warheads (halogens, cyano groups), our electrophilic heterocyclic fragment library targets non-conserved cysteine/lysine residues and screens covalent ligands through an electrophile-first workflow. It generates high-quality dual-functional fragments for KRAS, BTK and other popular targets, supporting MS and DEL high-throughput screening to accelerate covalent drug lead discovery.

MCE Electrophilic Heterocyclic Fragment Library Built on druggable heterocyclic backbones with tunable electrophilic warheads (halogens, cyano groups), our electrophilic heterocyclic fragment library targets non-conserved cysteine/lysine residues and screens covalent ligands through an electrophile-first workflow. It generates high-quality dual-functional fragments for KRAS, BTK and other popular targets, supporting MS and DEL high-throughput screening to accelerate covalent drug lead 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 18 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.

Energy metabolism is the most fundamental biochemical process in living organisms, encompassing glycolysis, the TCA cycle, oxidative phosphorylation, the pentose phosphate pathway, and fatty acid oxidation. These core pathways directly regulate cell survival, proliferation, differentiation, and apoptosis. Dysregulation of energy metabolism is closely linked to major diseases including cancer, diabetes, obesity, cardiovascular diseases, neurodegenerative disorders, and ischemia‑reperfusion injury. Targeting these metabolic pathways has become a frontier in drug discovery and mechanistic research.

The MCE Energy Metabolite Compound Library features 89 structurally defined small‑molecule compounds. It covers energy substrates, pathway intermediates, coenzymes and redox carriers, nucleotide derivatives, and microenvironmental modulators. This library is applicable to research areas including tumor metabolism, insulin resistance, mitochondrial dysfunction, oxidative stress, neuroprotection, and cardiometabolic diseases, providing a high‑quality tool for mechanistic studies, biomarker discovery, and high‑throughput drug screening.

In drug discovery and development (R&D) area, target binding and druggability optimization are core processes. Among these attributes, high solubility is critical for a compound to achieve druggability, as it directly impacts the progress of drug R&D. Superior solubility ensures the rapid dissolution and uniform distribution of drug molecules in vivo, thereby enhancing bioavailability and effectively mitigating issues such as suboptimal efficacy, increased dosage requirements, or exacerbated toxic and side effects arising from insufficient solubility.

From the perspective of medicinal chemistry, high-solubility drug fragments serve as high-quality "molecular building blocks". Based on these fragments, lead compounds with potential druggability can be rapidly screened out, which significantly shortens the drug R&D cycle and reduces R&D costs. Meanwhile, the high-solubility drug fragment library can provide diverse options for drug development in different therapeutic areas, offer solutions for the solubility defects of existing clinical drugs, and facilitate the development of novel, highly effective targeted drugs with higher bioavailability and better safety profiles.

MCE has collected and compiled 2,527 experimentally validated small-molecule fragments with high solubility. These fragments can be directly used for drug molecular design, providing high-quality pre-validated solubility fragments that significantly improve the efficiency of lead compound screening and accelerate the progress of drug R&D.

Macrocyclic scaffolds are increasingly valued in modern drug discovery for their exceptional activity against undruggable targets (proteases, kinases, PPIs). 2026 marks a key commercial breakthrough for oral macrocyclic peptides: enlicitide, the world’s first oral PCSK9 macrocyclic peptide, has received FDA approval. Macrocyclic candidates targeting KRAS and other classic undruggable targets have also entered clinical development, validating macrocyclization as an effective strategy to overcome druggability barriers.

Two core R&D directions lead current macrocyclic drug design: AI-driven de novo generation and structural optimization of small-molecule macrocycles, and macrocyclic peptides based on sequence design and conformational engineering. Macrocycle druggability hinges on embedded linkers, which determine cyclization efficiency, final conformation and drug-like properties. Bifunctional reaction orthogonality is the core linker selection criterion. Our linker library enables stepwise intramolecular cyclization with suppressed side reactions, accommodates varied ring sizes, and covers three key reaction systems: amide condensation, nucleophilic substitution and CuAAC click chemistry.

Built on classical macrocyclization systems, the library is processed through reaction classification, bifunctional orthogonality evaluation, novelty clustering and redundancy removal, with PROTAC long-chain and ADC cleavable linkers explicitly excluded. Featuring rigid, semi-rigid and flexible scaffolds, it is widely applicable to small-molecule macrocycle synthesis and linear peptide cyclization.

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 25 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 44 plant hormones, which can be used for identification in plant metabolomics and related botanical research.

Cysteine proteases (CPs), a key enzyme family regulating physiological metabolism and mediating pathological processes (e.g., abnormal bone resorption, tumour invasion, and pathogen infection), represent a core therapeutic target for disease intervention via the development of specific inhibitors. Currently reported CP covalent inhibitors encompass diverse structural types, including epoxides, aziridine, and activated double bonds (vinyl sulphones, α,β-unsaturated ketones), providing clear structural references for the development of novel CP covalent inhibitors.

This compound library contains multiple warheads that specifically target cysteine proteases, serving as a powerful tool for the efficient discovery of novel covalent inhibitors against this enzyme family.

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

Unnatural amino acids (UAAs), also referred to as non-canonical amino acids (ncAAs) or non-proteinogenic amino acids, are a class of amino acids that are distinct from the 20 standard natural amino acids. They can be obtained through chemical synthesis, biosynthesis, and other approaches, with structural diversity far exceeding that of natural amino acids. UAAs are mainly including naturally occurring non-canonical amino acids, chemically synthesized amino acids, and biosynthetic amino acids, which provide a molecular basis for protein function design.

UAAs exhibit significant value in multiple fields. They can optimize the pharmacokinetic properties of peptide drugs and peptidomimetics, modify enzyme functions and endow them with new biological activities, thereby overcoming the limitations of traditional peptide drugs and expanding the chemical space . Meanwhile, UAAs can serve as molecular probes to analyze protein-protein interactions and investigate the regulatory mechanisms of protein functions.

MCE has compiled a UAAs Fragment Library comprising nearly a thousand unnatural amino acid fragments with extensive coverage of chemical space and enhanced structural diversity. This compound library can be widely applied in peptide synthesis, drug design, and protein engineering.

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 147 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.

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.

Although there are more than 600 E3 ubiquitin ligases, only several with small molecule ligands have been used for designing PROTACs, including Skp1-Cullin-F box complex containing Hrt1 (SCF), Von Hippel-Lindau tumor suppressor (VHL), Cereblon (CRBN), inhibitor of apoptosis proteins (IAPs), and mouse double minute 2 homolog (MDM2).

MCE carefully prepared a unique collection of 187 ligands for E3 ligase, which have been reported to be used in PROTAC design. MCE E3 ligase ligand library is a useful tool for PROTAC development.

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

MCE offers a unique collection of 100 cyclic peptides, all of which have good bioactivities. MCE Cyclic Peptide Library is a powerful tool for drug discovery and PPI inhibitor screening.