Drug design

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.

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.

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.

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 5,259 compounds with confirmed high oral bioavailability. MCE Orally Active Compound Library is a useful tool for discovering new drugs with oral bioavailability.

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

MCE supplies a unique collection of 6,758 multi-target compounds that targets two or more different targets or different subtypes of the same target. MCE Multi-Target Compound Library can be used for target protein ligand screening or drug development.

Fragment-based drug discovery (FBDD) offers a strategic advantage by categorizing fragment hits according to their functional groups. This approach facilitates both the further optimization of these hits and the rational design of larger compounds through fragment combination. The amine functional group plays a vital role in drug development, as evidenced by its presence in many marketed drugs like Galantamine, Tacrine, and Rivastigmine. It is instrumental in enhancing solubility, improving bioavailability, and ensuring shelf-life stability—all critical factors for drug efficacy.

MCE offers a collection of 19,532 amine fragments for drug discovery. All of these compounds adhere to the Rule of Three (RO3) criteria for drug-likeness, which MCE offers a collection of 19,532 amine fragments for drug discovery, all of which stipulates a molecular weight ≤ 300 Da, ≤ 3 hydrogen bond donors, ≤ 3 hydrogen bond acceptors, and a cLogP ≤ 3.

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 3,601 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.

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 5,112 compounds with different covalent warheads that target cysteine. The MCE Cysteine Targeted Covalent Library is designed using the following covalent warheads: Acrylamides, Propiolic acid ester, Dimethylamine functionalized acrylamides, Chloroacetamides, Acrylonitrile, 2-Cyanoacrylamide, Aziridine, Haloacetamide, etc.

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.

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

MCE offers a unique collection of 705 Pediatric medicines, all of which have been approved or studied in clinical trials for children diseases. MCE children’s drug library is a useful tool for drug repurposing to discover new children’s indications.

Kinase is an enzyme that adds phosphate groups to other molecules. This process is known as phosphorylation. Protein phosphorylation is a key aspect in the regulation of a large number of cellular processes including cellular division, metabolism, signal transduction, and so on. There are over 500 kinases encoded by the human genome and it has been estimated that kinases regulate approximately 50% of cellular functions. Kinases are a large group of drug targets in drug discovery. Kinase inhibitors are an important class of drugs that block certain enzymes involved in diseases such as cancer and inflammatory disorders.

Kinase inhibitor library designed by MCE contains 3,849 kinase inhibitors and regulators mainly targeting protein kinases (VEGFR, EGFR, BTK, CDK, Akt, etc.), lipid kinases (PI3K, PI4K, SK, etc.) and carbohydrate kinases (Hexokinase), and is a useful tool for kinase drug discovery and related research.

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

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

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 250 small allosteric modulators. It is a good tool to be used for research on metabolize, cancer and other diseases.

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

MCE covalent inhibitor library contains 1,546 small molecules including identified covalent inhibitors and other bioactive molecules having common covalent reactive groups as warheads, such as acrylamides, activated terminal acetylenes, Sulfonyl fluorides/esters, cloracetamides, alkyl halides, epoxides, aziridines, disulfides, etc.

“BioDesign” approach incorporates key structural features of known pharmacologically relevant natural products (e.g. alkaloids and other secondary metabolites) into synthetically feasible medicinal chemistry scaffolds. In order to identify the privileged pharmacophores, ring systems and linkers, we have carried out statistical analysis of structural features of natural products, marketed drugs, and drug candidates.

Saturated, fused ring, spiro, and bridged systems with a tendency towards multiple chiral centers are highly privileged among natural products and marketed drugs yet these structures are very poorly represented in commercial libraries. This library addressed this market need by incorporating these privileged elements into the design of novel synthetic molecules with high molecular framework diversity, multiple stereogenic centers (≥2), and degree of saturation (Fsp3 > 0.5).

Protein protein interactions (PPI) have pivotal roles in life processes. The studies showed that aberrant PPI are associated with various diseases, including cancer, infectious diseases, and neurodegenerative diseases. The classic drug targets are usually enzymes, ion channels, or receptors, the PPI indicate new potential therapeutic targets. Therefore, targeting PPI is a new direction in treating diseases and an essential strategy for the development of new drugs.

However, the design of modulators targeting PPI still faces tremendous challenges, such the difficult PPI interfaces for the drug design, lack of ligands reference, lack of guidance rules for the PPI modulators development and high-resolution PPI proteins structures.

With the development of high-throughput technology, high-throughput screening is also gradually used for the identification of PPI inhibitors, but the compound library used for conventional target screening is not very effective in screening PPI inhibitors. To improve screening efficiency, MCE carefully selected 782 PPI inhibitors and mainly targeting MDM2-p53, Keap1-Nrf2, PD-1/PD-L1, Myc-Max, etc. MCE Protein-protein Interaction Inhibitor Library is a useful tool for PPI drug discovery and related research.

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

Taking advantage of our virtual screening, we conduct virtual screening of approved compound library and clinical compound library based on the 3CL protease (PDB ID: 6LU7), Spike Glycoprotein (PDB ID: 6VSB), NSP15 (PDB ID: 6VWW), RDRP, PLPro and ACE2 (Angiotensin Converting Enzyme 2) structure. We design a unique collection of 1,384 compounds which may have anti-COVID-19 activity. Anti-COVID-19 Compound Library will be a powerful tool for screening new anti-COVID-19 activity drugs.

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

MCE covalent inhibitor library contains 5,994 small molecules including identified covalent inhibitors and other molecules having common covalent reactive groups as warheads, such as acrylamides, activated terminal acetylenes, sulfonyl fluorides/esters, cloracetamides, alkyl halides, epoxides, aziridines, disulfides, etc.

MCE Covalent inhibitor Library plus, with more powerful screening capability, further complement Covalent inhibitor Library (HY-L036) by adding some fragment compounds with covalent warheads.

Owing to the high conservation of orthosteric sites, conventional orthosteric drugs frequently suffer from poor subtype selectivity, off-target toxicity, and drug resistance, severely restricting their clinical application. In contrast, allosteric sites feature low conservation, high hydrophobicity, weak polarity, confined spatial geometry, and dynamic cryptic properties. These characteristics endow allosteric modulators with distinct advantages including high selectivity, functional tunability, and improved safety, making allosteric therapy a key direction in modern drug discovery.

MCE has curated nearly 1,000 structurally disclosed clinical-stage allosteric modulators. By analyzing allosteric protein–ligand complex structures from the PDB database, we extracted core pharmacophores and privileged scaffolds. Adopting a rational design strategy of “scaffold derivation + allosteric physicochemical filtering”, we performed secondary screening on the derived compounds strictly following the optimal physicochemical principles for allosteric binding based on universal allosteric pocket properties: molecular weight 300–500 Da, HBD ≤ 3, HBA = 3–8, PSA = 70–120 Ų, rotatable bonds ≤ 6, highly rigid scaffolds, cLogP = 1.0–3.8, and no strongly ionizable groups. The selected compounds exhibit high rigidity and shape complementarity, making them well-suited for targeting shallow, dynamic, and hydrophobic-dominated allosteric pockets.

This allosteric modulator library contains 4,315 structurally diverse, lead-like compounds dedicated to allosteric drug development, allosteric site targeting, and allosteric modulator screening. It is suitable for kinases, GPCRs, and other important drug targets. All compounds are analogs of clinical-stage allosteric modulators with a similarity score > 0.6, combining excellent druggability and allosteric binding potential. It provides a highly efficient tool for early-stage allosteric drug discovery.

Peptidomimetics are compounds whose essential elements (pharmacophore) mimic a natural peptide or protein in 3D space and which retain the ability to interact with the biological target and produce the same biological effect. Peptidomimetics are designed to circumvent some of the problems associated with a natural peptide: e.g. stability against proteolysis (duration of activity) and poor bioavailability. Certain other properties, such as receptor selectivity or potency, often can be substantially improved. The design and synthesis of peptidomimetics are most important because of the dominant position peptide and protein-protein interactions play in molecular recognition and signaling, especially in living systems. Hence mimics have great potential in drug discovery.

MCE Peptidomimetic Library contains 370 compounds including peptoid, α-helix mimetics, β-turn/sheets mimetics, etc. This library is an indispensable tool of structure-activity relationships in drug discovery.

The incidence and significance of central nervous system diseases are increasing at an alarming rate all over the world. Although substantial research efforts have been applied to develop new CNS-active drugs, only a few CNS disorders are addressed satisfactorily, while the remaining ones pose significant clinical challenges. Blood-brain barrier (BBB) permeability is one of the most important limiting factors in the design and development of novel CNS-targeted pharmaceuticals for the treatment of neurological disorders.

Carefully selected from the HTS Compound Collection to meet the parameters optimized for high BBB-permeability, our CNS Focused Screening Library comprising over 30,300 structurally-diverse and potentially CNS-active screening compounds. This original Screening Compound Library is aimed at supporting CNS drug design projects and HTS efforts in search for novel neurotherapeutics.

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 1,100 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.

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.

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.

Protein protein interactions (PPI) have pivotal roles in life processes. The studies showed that aberrant PPI are associated with various diseases. However, the design of modulators targeting PPI still faces tremendous challenges, such the difficult PPI interfaces for the drug design, lack of ligands reference, lack of guidance rules for the PPI modulators development and high-resolution PPI proteins structures.

The PPI Library comprises molecules of various sizes, frameworks, and shapes ranging from fragment-like entities to macrocyclic derivatives designed as secondary structure mimetics or as epitope mimetics. The designs cover β-turn / loop mimetics and α-helix mimetics. Since helices present at the interface in 62% of all protein-protein interactions. This library focused on designs including mimics with the substitution geometry of an a-helices, as well as designs that mimic the location of “hot-spot” side chains in helix-mediated PPIs.

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 125 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.

Sulfonyl fluoride (-SO₂F) overcomes the bottleneck of target selectivity in traditional covalent warheads through its unique chemical and biological properties, which rely heavily on cysteine (Cys) residues. Featuring high stability and tunable electrophilicity under physiological conditions, it can target a wide range of nucleophilic residues including lysine (Lys), tyrosine (Tyr), serine (Ser), and histidine (His). It offers the advantages of a broader druggable space, lower off-target risks, and long-lasting efficacy, with numerous reported cases in the research of covalent inhibitors, Molecular glue, PROTACs, and chemical biology probe development.

MCE constructs a highly diverse sulfonyl fluoride fragment library based on the reactivity, stability and physiological compatibility of sulfonyl fluoride. The library contains 1000 efficiently synthesized and stable sulfonyl fluoride fragments, which ensure precise reactivity of the warhead and retain sufficient derivatization space for subsequent optimization. Combined with the modular strategy of SuFEx click chemistry, it enables versatile modification of compounds and functionalization of complex molecules, improves the efficiency of structural optimization and rapidly expands druggability, making it suitable for high-throughput probe and custom covalent library construction. It provides an efficient research tool for the development of broad-spectrum covalent inhibitors targeting Lys/Tyr/Ser/His, covalent PROTACs for E3 ligases and chemical biology probe development, meeting the requirements of modern drug research for high throughput, high success rate and high derivatization potential.

This library contains 1,162 sulfonyl fluoride fragments with high structural diversity, favorable drug-like properties and tunable electrophilicity. It is well suited for precise targeting of non-Cys residues and meets the criteria of simple structure and high derivatization potential. It effectively improves

Macrocycles are promising scaffolds for the design of novel RNA targeting molecules. This collection of macrocycles for RNA consists of very diverse, drug-like molecules which incorporate certain known RNA-recognition elements (e.g. nucleobase ring systems and analogs) distributed within macrocyclic rings or peripheral fragments. As macrocyclic molecules tend to be larger than traditional screening molecules, it is vital to carefully assess and control their physicochemical properties. All macrocycles have been tested for aqueous and DMSO solubility with cutoffs applied at 10 mM in DMSO and 50 µM in PBS (pH 7.4); PAMPA permeability has also been tested for representative set of macrocycles.

Research has shown that drugs targeting aging pathways demonstrate promising potential in models of age-related diseases such as Alzheimer's disease, cardiovascular diseases, metabolic syndrome, osteoarthritis, and various malignancies. This suggests that intervening in the biological processes of aging may enable synergistic prevention and treatment of multiple chronic diseases. Against the backdrop of the gradual elucidation of core aging mechanisms-including cellular senescence, telomere attrition, epigenetic dysregulation, and chronic inflammation anti-aging research has shifted from traditional phenotypic interventions toward targeting key pathways that regulate biological age.

The MCE Anti-Aging Compound Library Mini is precisely built upon this cutting-edge concept. It focuses on aging-related targets validated through genetic or functional studies, comprising 381 compounds designed to provide systematic research tools for aging biology and intervention strategy development. The library covers core mechanisms such as mTOR, SIRT, energy metabolism, clearance of senescent cells, optimization of mitochondrial function, and telomere maintenance. For each target, 1-5 compounds with clear activity and strong representativeness have been carefully selected, spanning the entire translational spectrum from preclinical tool molecules to clinically investigational drugs.

In contrast to the high conservation of conventional orthosteric sites, allosteric sites possess structural characteristics of low conservation, high hydrophobicity, weak polarity, confined spatial geometry, and dynamic cryptic properties. There is a significant difference between their core structures and orthosteric pockets — allosteric pockets are mostly dynamic grooves formed by protein conformational changes, subunit interface clefts, or shallow depressions, rather than the rigid "keyhole" structure of orthosteric sites. With looser spatial constraints, allosteric sites have the advantages of high selectivity and low off-target risk, and have become an important direction in new drug discovery.

Based on the dynamic, hydrophobic, and narrow-long spatial characteristics of allosteric pockets, MCE has performed targeted modification and screening of fragments. The screening criteria strictly conform to the requirements of allosteric binding: molecular weight is controlled at 120–280 Da (to meet the core needs of small molecules in fragment libraries and high derivatization), hydrogen bond donors (HBD ≤ 2), hydrogen bond acceptors (HBA ≤ 3), polar surface area (PSA = 30–80 Ų), rotatable bonds (≤ 2), moderate hydrophobicity (cLogP = 1–3.5), no strongly ionizable groups, and both appropriate rigidity and conformational flexibility to adapt to the dynamic changes of the pocket. Meanwhile, combined with the results of principal moment of inertia (PMI) analysis, fragments with high 3D diversity were obtained. Such fragments have good shape complementarity with allosteric pockets, ensuring that the fragments can smoothly enter the allosteric pockets and form stable binding, while providing room for subsequent optimization and derivation.

This library contains 1,800 structurally diverse fragment molecules with excellent drug-like properties, suitable for allosteric drug development and the design and optimization of allosteric sites. It combines the

Unlike the 20 natural amino acids commonly found within living organisms, non-natural amino acids are synthesized through chemical or biosynthetic methods, thereby being endowed with unique chemical properties or biological activities. In drug development, these amino acids can be utilized to design novel pharmaceutical molecules that may exhibit superior pharmacological characteristics, such as increased selectivity, improved pharmacokinetic profiles, or reduced toxicity. In biomedical research, uon-natural amino acids can act as biological markers or probes for investigating biological processes like cell signaling, protein conformation, and protein-protein interactions. In addition, non-natural amino acids can also be used in the field of agriculture to develop new pesticides, plant growth regulators and so on.

Targeted Protein Degradation (TPD) is a novel and promising approach to drug development. It shows great potential for targeting proteins traditionally considered "undruggable" due to the lack of enzymatic function and absence of binding sites by tagging them for degradation or recruiting natural degradation mechanisms.

Molecular glues are a type of small-molecule degraders that primarily induce novel interactions between E3 ubiquitin ligases and target proteins, forming ternary complexes that lead to protein ubiquitination and subsequent proteasomal degradation. Compared with PROTACs, molecular glues generally have lower molecular weights, higher cell permeability, and better drug-like properties. Additionally, the design of molecular glues is relatively simple, without the requirements for complex linkers and ligand optimization. As a result, molecular glues have gradually emerged as a promising therapeutic approach for various diseases.

Multiple types of molecular glues have been reported previously. Analysis of co-crystal complex structures reveals that CRBN-related molecular glues are more versatile. Therefore, MCE researchers select active molecules related to these targets as probes for artificial intelligence (AI) screening.Subsequently, molecular docking technology was used to verify whether the screened molecules retained the key pharmacophore features. Ultimately, we obtained 317 molecular glue analogs, and these compounds serve as powerful tools for the research of molecular glues.

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

Lysine is the second most common target residue used in the design of TCIs and related covalent ligands. Its appeal lies in its abundance in human proteins, which is approximately three times higher than that of cysteine (5.8% vs. 1.9%). This significantly increases the number of proteins suitable for covalent targeting, especially given that many human proteins lack ligandable cysteine residues. Moreover, it has been suggested that functional lysines have a lower probability of being replaced by mutation, as they often play a crucial role in catalysis by acting as bases or nucleophiles. Additionally, lysines are essential for maintaining the structural integrity of proteins and for regulating post-translational modifications (PTMs). Consequently, targeting lysine has garnered significant interest in recent years.

Through careful selection, we constructed a structural filter containing over 110 electrophilic groups. By analyzing the electrophilic fragments selected by the structural filter, we removed any molecules with trivial or undesirable structural features. Ultimately, we obtained 445 fragment molecules which can target lysine residue and can be used for fragment-based covalent drug discovery.

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

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 5,860 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.