Efficient

Unlike highly conserved orthosteric sites, allosteric sites exhibit low conservation, high hydrophobicity, weak polarity, confined geometry, and dynamic cryptic properties. Rather than rigid keyhole-like cavities, they typically appear as flexible grooves, subunit interface clefts, or shallow depressions formed by protein conformational changes.

Based on the dynamic, hydrophobic, and elongated nature of allosteric pockets, MCE has carried out targeted fragment modification and screening under strict physicochemical criteria: MW 120–280 Da, HBD ≤ 2, HBA ≤ 3, PSA 30–80 Ų, rotatable bonds ≤ 2, cLogP 1–3.5. High 3D diversity was further ensured by PMI analysis, yielding fragments with excellent shape complementarity to allosteric pockets.

This library contains 1,800 structurally diverse, drug-like fragments, this library supports allosteric drug development and pocket optimization. It significantly improves screening hit rates and enables efficient, precise early-stage R&D of allosteric drugs.

Linkers, as key structural units in PROTAC molecules that connect the two functional ends, not only determine the overall molecular conformation and spatial compatibility but also directly influence the stability of the ternary complex, as well as cellular permeability and degradation efficiency. In recent years, with the widespread application of click chemistry in medicinal chemistry, the incorporation of bioorthogonal reactive groups such as azides (-N₃) into PROTAC linker design has become an emerging research focus, providing an important tool for modular assembly and rapid structural optimization.

The MCE Azide PROTAC Linker Library contains 0 linkers specifically designed for targeted protein degradation molecule design and optimization. These linkers serve as efficient “click handles,” enabling rapid and highly selective covalent coupling with alkyne reaction partners, thereby facilitating modular assembly and structural diversification of PROTAC molecules. In drug development, this design not only improves the efficiency of molecular construction but also significantly accelerates the screening and optimization of lead compounds. Meanwhile, by tuning linker properties such as length, flexibility, and polarity, the ability to form ternary complexes and degradation activity can be optimized.

Orthosteric sites are highly conserved, leading to poor subtype selectivity, off-target toxicity and drug resistance in traditional drugs. By contrast, allosteric sites show low conservation, high hydrophobicity, weak polarity, confined geometry and dynamic cryptic properties, granting modulators high selectivity, functional tunability and safety. Thus, allosteric therapy has become a major focus in drug discovery.

MCE curated nearly 1,000 clinical-stage allosteric modulators, analyzed PDB complex structures to identify key pharmacophores and privileged scaffolds, then designed and filtered compounds using rational “scaffold derivation + physicochemical screening” with strict property criteria. The resulting compounds show high rigidity and shape complementarity to shallow, dynamic, hydrophobic allosteric pockets.

This library comprises 4,315 diverse, lead-like compounds ideal for allosteric drug discovery and target screening, covering kinases, GPCRs and more. All are analogs of clinical-stage molecules with similarity > 0.6, combining high druggability and allosteric binding potential to support efficient early-stage R&D.

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 437 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.

In this era of rapid advancement in gene-editing technology, the CRISPR-Cas system, with its powerful programmability, is leading a transformation in life sciences research. It enables efficient and precise targeted modification of an organism's genome, providing a robust tool for studying gene function, treating genetic diseases, and improving crop varieties. However, bottlenecks such as insufficient editing efficiency, low homologous directed repair efficiency, and potential off-target risks remain major challenges in achieving precise genetic modifications and developing gene therapies.

To overcome these limitations, the MCE High-Efficiency Gene Editing Compound Library systematically includes 761 small molecules that are known or have the potential to enhance gene-editing efficiency. These compounds work by targeting and modulating the DNA damage repair network, mechanistically inhibiting non-homologous end joining, promoting homologous directed repair, or regulating chromatin states and cellular responses, thereby significantly optimizing editing outcomes. This library is suitable for developing "CRISPR-small molecule" combination therapy strategies, improving gene-editing efficiency, and providing a powerful tool for in-depth research into the mechanisms of DNA damage repair in gene editing.

Techniques for reprogramming somatic cells create new opportunities for drug screening, disease modeling, artificial organ development, and cell therapy. The development of reprogramming techniques has grown exponentially since Yamanaka reprogrammed somatic cells to become induced pluripotent stem cells (iPSCs) using four transcription factors, OCT4, SOX2, KLF4, and c-MYC in 2006. Despite the development of efficient reprogramming methods, most methods are inappropriate for clinical applications because they carry the risk of integrating exogenous genetic factors or use oncogenes. Alternative approaches, such as those based on miRNA, non-viral genes, non-integrative vectors, and small molecules, have been studied as possible solutions to the problems. Among these alternatives, small molecules are attractive options for clinical applications. Reprogramming using small molecules is inexpensive and easy to control in a concentration- and time-dependent manner. It offers a high level of cell permeability, ease of synthesis and standardization, and it is appropriate for mass-producing cells.

MCE Reprogramming Compound Library contains a unique collection of 3,231 compounds that act on reprogramming signaling pathways. These compounds are potential stimulators for reprogramming. This library is a useful tool for researching reprogramming and regenerative medicine.

Ionizable lipids are a class of specialized, functional lipid molecules with pH-sensitive charge characteristics. They are primarily divided into two major categories: ionizable cationic lipids and ionizable anionic lipids, though the term typically specifies ionizable cationic lipids within the biomedical field. Structurally, these lipids consist of an ionizable hydrophilic headgroup, a biodegradable linker, and hydrophobic tails. Their primary application is serving as the key delivery vehicle in lipid nanoparticles (LNPs) to encapsulate negatively charged nucleic acid macromolecules, such as mRNA vaccines, siRNA therapeutics, and CRISPR gene-editing components. In a physiological, neutral environment, they remain electrically neutral to minimize systemic toxicity and prolong circulation time. Upon entering the acidic microenvironment of cellular endosomes, however, they undergo protonation to become positively charged, thereby inducing membrane fusion and enabling the highly efficient intracellular release of the nucleic acid cargo. Consequently, they serve as the technological cornerstone for bringing nucleic acid therapies into clinical application.

To accelerate the translational process of cutting-edge nucleic acid drugs, MCE has meticulously constructed an ionizable lipid compound library containing 93 high-performance molecules, aiming to provide researchers and pharmaceutical professionals with a high-throughput, multi-dimensional lipid screening platform.

PD-1/PD-L1 are key immune checkpoint targets that suppress T-cell-mediated anti-tumor immunity, representing a major focus in cancer immunotherapy. While antibody drugs dominate the clinic, they are limited by administration challenges and immune-related side effects. Small-molecule PD-1/PD-L1 inhibitors, with oral availability, good tissue penetration and low cost, have emerged as a promising next-generation strategy.

A PD-1/PD-L1 lead-like library was built via a five-step virtual screening process. After collecting 8,947 inhibitors from BindingDB and PubChem and filtering by activity and duplicates, AI similarity screening was performed using GeminiMol. Key pharmacophores were extracted from the PPI interface of co-crystal structures, and molecular was screened via a pharmacophore model, effectively enhancing target activity.

Containing 10,000 structurally diverse and drug-like molecules well-matched to the PD-L1 pocket, the library supports virtual docking, high-throughput screening and hit discovery, enabling efficient and rapid development of small-molecule immunotherapies.

In PROTAC drug development, linkers are often one of the key variables determining drug-likeness and degradation efficiency. Since PROTAC systems must simultaneously satisfy target protein binding, E3 ligase recruitment, and intracellular spatial conformational matching, their structural design is essentially a multi-parameter optimization problem. Differences in linker rigidity, flexibility, and spatial extension can significantly influence the formation pathway and stability of the ternary complex, leading to substantial variations in degradation activity. Therefore, the development of linker systems with modular tunability and high structural expandability has become an important direction in PROTAC optimization.

The MCE Alkyne PROTAC Linker Library contains 0 linkers based on terminal and internal alkyne scaffolds, forming a highly derivatizable linker module system. These linkers serve as standardized building blocks for rapid assembly and iterative optimization of PROTAC molecules, and support efficient conjugation with azide-containing functional groups via click chemistry. In practical drug development, this type of structure not only facilitates the construction of diverse linker space libraries, accelerating lead compound screening, but also enables systematic tuning of molecular geometry and physicochemical properties, thereby improving ternary complex stability and targeted protein degradation efficiency.

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.

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 6,182 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.

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.

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.

MCE-18 stands for Medicinal Chemistry Evolution 2018, which was first published in Journal of Medicinal Chemistry in 2019 for assessing molecular novelty and three-dimensional complexity. Developed based on Clarivate global pharmaceutical patent database, this descriptor was constructed via big-data analysis covering 28,161 patented lead compounds, 1,370 approved drugs and nearly 30,000 preclinical-to-phase III drug candidates from 23 top pharmaceutical companies worldwide between 1950 and 2018, followed by structural clustering and removal of redundant outdated scaffolds for data denoising. Its scoring system integrates five core structural features including aromatic ring (AR), aliphatic heterocycle (NAR), chiral center (CHIRAL), spiro atom (SPIRO), cyclic and acyclic sp³ carbon ratio together with a quadratic topological correction factor. Breaking the limitations of the single Fsp³ parameter, MCE-18 effectively distinguishes conventional flat aromatic scaffolds from modern 3D-enriched novel chemotypes, overcoming typical drawbacks of traditional compound libraries such as scaffold redundancy, low screening hit rates and poor compatibility with allosteric and PPI-related difficult targets.

This library contains over 37,000 structurally diverse compounds with favorable overall drug-likeness, suitable for high-throughput screening against canonical targets including kinases, GPCRs and proteases as well as challenging allosteric and PPI targets. Compounds comply with the developmental trend of modern novel drug discovery, supporting routine primary screening as well as early hit identification of allosteric modulators and PPI inhibitors, serving as an efficient screening resource for early-stage innovative drug discovery.