Structural modifications

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.

Dipeptide compounds have attracted extensive attention in drug discovery and life science research due to their simple structures, ease of modification, and favorable biocompatibility. As small peptides composed of two amino acids, dipeptides exhibit diverse biological activities, including anti-inflammatory, antioxidant, antimicrobial, anticancer, and immunomodulatory effects, showing significant application potential in metabolic disorders, neurological diseases, and cancer research. Compared with traditional small molecules, dipeptide compounds possess favorable target-binding properties and high structural plasticity, making them valuable tools for drug screening and mechanism studies.

The MCE Dipeptide Compound Library contains 72 dipeptide compounds and can be applied to peptide drug discovery and development.

A histone modification, a covalent post-translational modification (PTM) to histone proteins, includes methylation, phosphorylation, acetylation, ubiquitylation, and sumoylation, etc. In general, histone modifications are catalyzed by specific enzymes that act predominantly at the histone N-terminal tails involving amino acids such as lysine or arginine, as well as serine, threonine, tyrosine, etc. The PTMs made to histones can impact gene expression by altering chromatin structure or recruiting histone modifiers. Histone modifications act in diverse biological processes such as transcriptional activation/inactivation, chromosome packaging, and DNA damage/repair. Deregulation of histone modification contributes to many diseases, including cancer and autoimmune diseases.

MCE owns a unique collection of 931 bioactive compounds targeting Epigenetic Reader Domain, HDAC, Histone Acetyltransferase, Histone Demethylase, Histone Methyltransferase, Sirtuin, etc. Histone Modification Research Compound Library is a useful tool for histone modification research and drug screening.

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

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

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

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.

Protein phosphorylation is a key post-translational modification underlying the regulation of many cellular processes. Phosphatases and kinases contribute to the regulation of protein phosphorylation homeostasis in the cell. This reversible regulation of protein phosphorylation is critical for the proper control of a wide range of cellular activities, including cell cycle, proliferation and differentiation, metabolism, cell-cell interactions, etc.

Protein phosphatases have evolved in separate families that are structurally and mechanistically distinct. Based on substrate specificity and functional diversity, protein phosphatases are classified into two superfamilies: Protein serine/threonine phosphatases and Protein tyrosine phosphatases. Ser/Thr phosphatases are metalloenzymes belonging to two major gene families termed PPP (phosphoprotein phosphatase) and PPM (metal-dependent protein phosphatases), whereas protein tyrosine phosphatases (PTPs) belong to distinct classes of enzymes that utilize a phospho-cysteine enzyme intermediate as a part of their catalytic action.

MCE supplies a unique collection of 185 phosphatase inhibitors that mainly targeting protein tyrosine phosphatases (PTPs) and serine/threonine-specific protein phosphatases. MCE Phosphatase Inhibitor Library is a useful tool for phosphatase drug discovery and related research.