lead candidates

Currently,the incidence and mortality rates of clinical fungal infections remain high. Existing antifungal drugs are limited in variety and associated with numerous adverse effects, creating an urgent demand for the development of novel antifungal agents. Antifungal compound libraries can support the screening and development of new antifungal drugs.

The mechanisms of action of antifungal drugs cover key processes such as fungal cell membrane synthesis, cell wall synthesis, and cell division. They exert fungicidal or fungistatic effects by specifically targeting different molecular pathways. This library includes a variety of core analogs of antifungal drugs, making it adaptable to antifungal research in diverse scenarios. It can be used for the high-throughput screening of novel antifungal drug candidates, enabling the rapid identification of compounds with potential antifungal activity and facilitating the elucidation of drug-target interactions and resistance mechanisms. Additionally, it supports the screening of compounds and combinations that reverse drug resistance, thereby uncovering the novel antifungal potential of existing compounds.

The library comprises 8350 compounds with a well-defined screening strategy. The core sources of the compounds include analogs of known antifungal active moleculeswith a similarity score of ≥ 0.6 MCE has collected more than 500 antifungal molecules.All screened compounds conform to lead-like physicochemical properties, exhibiting both structural diversity and drug-like characteristics, and providing valuable support for the research and development of novel antifungal drugs.

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

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

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

The rising prevalence of multidrug-resistant and extensively drug-resistant bacteria, combined with emerging resistance mechanisms and the limitations of existing antibacterial drugs, creates an urgent need for novel antibacterial agents. Antibacterial compound libraries serve as key tools to support antibacterial drug screening and development.

This library features structurally diverse compounds, including small-molecule scaffolds and natural product derivatives, and exhibits diverse antibacterial mechanisms of action. For example, these compounds exert antibacterial effects by disrupting bacterial cell structures, interfering with bacterial metabolic processes, and inhibiting nucleic acid synthesis. The derivation of scaffold structures enhances their activity against drug-resistant bacteria and their selectivity against different types of bacteria. This library can be used for the high-throughput screening of novel antibacterial drug candidates and the identification of potent compounds against drug-resistant and multidrug-resistant bacteria. Additionally, it provides a reference for compound structural modification, enabling further in-depth research on the structure-activity relationships(SARs) of antibacterial drugs. It can also be applied to the exploration of bacterial resistance mechanisms and reversal strategies, as well as the discovery of antibacterial molecules that inhibit efflux pumps and restore drug susceptibility.

The library contains 10855 structurally diverse drug-like compounds. Its core compound sources include analogs of known antifungal active moleculeswith a similarity score of ≥ 0.6. MCE has collected more than 1900 antibacterial molecules. All screened compounds conform to lead-like physicochemical properties, providing valuable support for the research and development of novel antibacterial drugs.

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 5,488 compounds with confirmed high oral bioavailability. MCE Orally Active Compound Library is a useful tool for discovering new drugs with oral bioavailability.

Seven-membered rings are privileged medium-sized scaffolds with distinct twist-chair conformations and greater 3D diversity than five- and six-membered rings. Their flexible conformations allow induced-fit protein binding and precise pharmacophore positioning. They also modulate Fsp³, pKa and logP to enhance solubility and permeability. Azepanes, oxepanes and benzodiazepines serve as bioisosteres for hit discovery against GPCRs, ion channels and kinases.

Widely found in plant and microbial alkaloids, seven-membered heterocycles show excellent biocompatibility and target affinity. They underpin many approved drugs for CNS, cancer and infectious diseases, including diazepam, imipramine and carbamazepine. Clinical candidates further highlight their unique value. However, high transannular strain and synthetic difficulty limit their availability, leaving them rare in standard screening libraries.

MCE 7 Membered Scaffold Library contains 2,792 structurally diverse, lead-like molecules covering azepanes, oxepanes, benzodiazepines and dibenzazepines. With varied substitutions, chiral centers and synthetic accessibility, it fills the shortage of medium-ring scaffolds. Ideal for HTS, virtual screening and SAR studies, these novel, patent-clear compounds offer a distinctive starting point for drug discovery in CNS disorders, oncology, antivirals and challenging targets such as PPIs.

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.

MCE 18 stands for Medicinal Chemistry Evolution 2018. This metric was established based on structural data of 28,161 patented lead molecules, 1,370 marketed innovative drugs, and nearly 30,000 investigational candidates from preclinical to Phase III stages across 23 major global pharmaceutical companies from 1950 to 2018. After scaffold clustering analysis, a scoring model was constructed by integrating five three dimensional scaffold characteristics, including aromatic rings (AR), non aromatic heterocycles (NAR), chiral centers (CHIRAL), spirocycles (SPIRO), and the sp³ carbon ratio in cyclic and acyclic moieties, enabling quantitative assessment of molecular scaffold novelty and three dimensional complexity.

According to the score distribution of patented molecules, the top 25% of the original patent dataset was defined as the high novelty region. MCE 18 high scoring compounds selected based on this criterion can effectively avoid scaffold patent conflicts and intellectual property risks from the source. Molecules in this range typically feature a high sp³ carbon ratio, abundant chiral centers, spirocycles, and fused heterocycles with prominent three dimensional conformations. Their spatial properties allow precise matching to complex non traditional undruggable target pockets such as PPI interfaces and allosteric sites, making them ideal structural types for early stage screening of First in class drugs.

MCE‑18 Novelty Focused drug‑Like library strictly selects molecules from the aforementioned high scoring range, containing more than 10,000 premium drug like molecules with highly diverse scaffolds and rich 3D diversity. It can be used for high throughput screening of well established targets such as kinases, GPCRs, and proteases, and is especially suitable for hit identification in allosteric modulation, protein–protein interactions, and various undruggable orphan targets, fully supporting early stage drug discovery for cutting edge innovat