Behind the Scenes of Enamine’s REAL Space


Behind the Scenes of Enamine’s REAL Space

April 15, 2024 16:43 CEST

Since its launch in 2018, Enamine’s REAL Space has made a significant impact in revolutionizing the landscape of compound collections. The initial version contained approximately 650 million compounds, establishing itself as one of the expansive catalogs of commercially available molecules for drug discovery. Notably, the first release rivaled even the esteemed ZINC15 database in terms of sheer scale and accessibility. Over time, Enamine’s REAL Space has continued to evolve and expand, further solidifying its position as a cornerstone resource for researchers seeking diverse and readily accessible compound libraries to expand their drug discovery hunting grounds.

Figure 1. Evolution of Enamine’s REAL Space over the years. Different version of the ZINC database are included for comparison.


The recipe for its success is both straighforward and captivating: Enamine utilizes a large number of common and proprietary building blocks, combining them with robust chemical reactions. The latest version of Enamine’s REAL Space which was released in February 2024 features 48,078,672,450 virtual products based on 154,119 on-stock reagents and building blocks, as well as 166 defined chemical rules to combine them. The constant validation of synthethic procedures and fine-tuning of the reaction rules with machine learning methods achieves constant synthesis success rates of over 80%. For this, Enamine experimentally checks for yields and success rates for representative reagents, functional group tolerance, as well as purification and product stability issues.

Figure 2. Numbers of building blocks featuring particular functional groups commonly used in the synthesis of drug-like molecules.


The orchestrated machinery of Enamine’s compound synthesis enables them to fulfill orders for as many as 300 compounds within a timeframe of just three to four weeks. This streamlined process not only ensures rapid delivery but also maintains the high quality and reliability synonymous with Enamine’s services, providing researchers with swift access to the compounds they need for their scientific endeavors.

At BioSolveIT, we specialize in developing algorithms hand in hand with academic institutions and pharmaceutical companies. These algorithms are specifically designed to swiftly extract relevant chemistry from ultra-vast Chemical Spaces, such as the REAL Space. The ligand-based methods include fuzzy pharmacophore screening (FTrees/Scaffold Hopper), fingerprint similarity search (SpaceLight/Analog Hunter) and substructure matching (SpaceMACS/Motif Matcher). Each results provides you with relevant molecules based on the needs of the project. Try out our Chemical Space navigation platform infiniSee to check for yourself for accessible compounds for your ligand of interest.

Figure 3. Search results retrieved with different algorithms for the drug Risdiplam.


As a matter of fact, the REAL Space represents only a subgroup of the comprehensive REAL compounds containing drug-like molecules with respective properties. With each successive iteration the REAL Space will grow even further and provide even more diverse chemistry. We eagerly anticipate the unfolding developments within the REAL Space and are looking into a bright future in the ongoing collaboration with Enamine!