ZINC26:Help

This is the help page for ZINC26. It is written specifically as guidance for using the interactive and batch features of ZINC26. Other information about ZINC26 can be found via the ZINC26 page.

ZINC26 is a search tool for purchasable and precedented bioactive chemical space. It uses Smallworld and Arthor technology from NextMove Software to allow billions of molecules to be searched in seconds. There are three ways to use ZINC26: Interactive, Batch, and an API.

Batch interface

ZINC26 batch allows you to search all purchasable molecules to find the most similar in a short transaction. The resulting zip file can be downloaded and opened with DataWarrior (openmolecules.org, free). A guide on using DataWarrior to navigate the results is available ZINC26:DataWarrior.

Interactive interface

ZINC26 has many catalogs of both purchasable and bioactive compounds, which allow many interesting questions to be answered almost instantly. The interactive interface searches specific databases subsets you select, from a few to a few billion molecules each.

Organization

• Top level: Purchasable and Bioactive
• within purchasable:
  • aristoInStock - our preferred sources for inStock compounds
  • aristoOnDemand - our preferred sources for onDemand compounds
  • bBlocks - building blocks for synthesis
  • commons - chemistry commons
  • covalent - covalent
  • inStock
  • onDemand
  • Sundry
• within bioactive: inVitro (e.g. ChEMBL), inVivo (e.g. drugs), natural (natural products, metabolites)

Anonymous users can search for one molecule at a time in the batch interface, while logged in users may search for up to 10 molecules in a single transaction.

We throttle usage in other (so far undisclosed) ways that allow us to offer a free public service without overloading.

Collectively, ZINC26 allows "what if" type searches of purchasable and biologically precedented chemical space. It allows the following questions.

• what are the most similar molecules I can purchase?
• what the most most similar molecules I can purchase from a particular vendor (within a particular HAC range)?
• Does vendor X sell compounds that look like my compound?
• what is the nearest drug to my compound?
• what is the nearest chembl bioactive 1uM or better to my compound?
• what is the nearest ligand for some gene product, say DRD4, 1uM or better, to my compound?
• what is the nearest natural product to my compound?
• what is the nearest metabolite to my compound?

Updates / Status

• As of July 2, 2026, zinc26 is in production at zinc26.docking.org.
• We have indexed most of the commercially available libraries that are distributed as enumerated libraries. Synthon-based libraries will be enumerated, but it takes time (ask the vendor to enumerate up to HAC29 and send it to us, and we will index it)
• We are aiming to offer "all purchasable to HAC29" and "all bioactives" as one-click interactive databases. So far, we are not quite there, but we are close. Use the batch interface until that is ready. It may turn out that we need to offer.
• all-purchasable-to-HAC25, and then one by one by HAC after that, in order to provide good interactive service. But we are trying to do it to HAC29.

how to report suggestions / problems

Please use our usual form for reporting problems: https://forms.gle/LZV1FCmLWxUWznVi9

• Please send us catalogs that you do not see indexed.