1. Screening Libraries
  2. Virtual Screening

Virtual Screening

In the last decades, high-throughput screening (HTS), which refers the experimental screening of large libraries of chemicals against a biological target, plays a crucial role in the identification of new lead compounds in the early-stage drug discovery. However, HTS requires expensive equipment and facilities, and its success depends on the size of the

compound library. The high cost and low hit rate associated with HTS have stimulated the development of in silico virtual screening (VS). Virtual screening is a computational technique used to search libraries of small molecules in order to identify those structures which are most likely to bind to a drug target. Nowadays, it has become a crucial step in early-stage drug discovery owing to its unique advantages over experimental HTS: drug target-relevant, competitive price and efficient.

MedChemExpress (MCE) provides high quality virtual screening service that enables researchers to identify most promising candidates. Based on the laws of quantum and molecular physics, our virtual screening services can achieve highly accurate results. Our optimized virtual screening protocol can reduce the size of chemical library to be screened experimentally, increase the likelihood to find innovative hits in a faster and less expensive manner, and mitigate the risk of failure in the lead optimization process.


The virtual screening methods are mainly divided into two types: structure-based virtual screening (SBVS) and ligand-based virtual screening (LBVS).

•   SBVS

The general scheme of a SBVS strategy starts with processing the 3D target structural information of pharmaceutical protein interested (determined either experimentally or computationally through homology modeling) and then dock the small molecules to targeted binding sites. These docked compounds are then ranked based on their predicted binding affinity or complementarity to the binding site, as well as other criteria. Usually only a few top-ranked compounds are selected as candidates for further experimental assays. Our fast and accurate ligand docking and scoring procedures lead to efficient virtual screening.

•   LBVS

In the absence of 3D structures of potential drug targets, LBVS is one of the most popular approaches for drug discovery and lead optimization. Biological data are explored in order to identify known active or inactive compounds that will be used to retrieve other potentially active molecular scaffolds for experimental evaluation. LBVS methods include approaches such as similarity and substructure searching, quantitative structure-activity relationships (QSAR), pharmacophore mapping, and machine learning.

Screening Process

•    Target research

•    Model building

•    Preparation of small molecule compound library

•    Molecular docking/pharmacophore mapping

•    Scoring/ranking

•    Compound selection


•    Ligand-based and structure-based virtual screening

•    Super high-performance computer

•    Compound database containing over 2 million purchasable compounds

•    3D pharmacophore model building

•    Consideration of water and solvation effects

Compound Databases

MCE Bioactive Compound Library 5,147 A unique collection of 5,147 bioactive and structurally diverse compounds. Bioactivity and safety confirmed by preclinical research and clinical trials. Some have been approved by FDA.
MCE Fragment Library 8,511 Latest release of Ro3 Fragment Library comprising over 8,511 high-quality molecules. A useful tool for the fragment-based approach to drug discovery (FBDD).
HTS Compound Library 1,971,081 Enamine HTS Collection contains 1,971,081 diverse screening compounds. These compounds frequently have unusual structures and unique properties.  The collection is particularly recommended for the researchers looking for most diverse screening set.
Advanced Library 486,874 Enamine Advanced Collection contains 486,874 compounds that have lead-like properties with MW ≤ 350, ClogP ≤ 3, and RotBonds ≤ 7 and/or valuable pharmacophores such carboxylic, primary amino and amide groups.
Premium Library 137,597 Enamine Premium Collection contains over 137,597 compounds having most favorable molecular properties (high Fsp3, low logP and MW).

MCE virtual screening services can significantly improve the hit rates and reduce the costs of compound screening. If you have any questions, please do not hesitate to contact us via email [email protected]