Yet Another Free Chemistry Database: Heterocycles Web Edition

Yet another free chemistry database comes in the form of a service run by the journal Heterocycles. The Heterocycles Web Edition offers two ways to search for heterocylic ring systems: by structure or by synthesis.

You may assume that these services would only search the contents of Heterocycles. It would then be a pleasant surprise to find a number of highly-regarded journals being covered. Here are some of titles:

• Angew. Chem. Int. Ed. Engl.
• Chem. Eur. J.
• Eur. J. Org. Chem.
• Heterocycles
• J. Am. Chem. Soc.
• J. Med. Chem.
• J. Nat. Prod.
• J. Org. Chem.
• Org. Lett.
• Synlett
• Tetrahedron
• Tetrahedron Lett.

The current query interface supports text only, although a number of important criteria can be used. I haven't searched for many heterocyles, but my results for indolizidine give a flavor for what you might expect (the actual number of hits was 115):

It would be interesting to know how Heterocycles populated its database. Is it text-mining, manual curation, both, or something else? Regardless of how it's done, Heterocycles Web Edition is definitely worth looking at.