Resources

A resource is the type of thing you are asking for (substance, catalog, gene, etc). Resources are written as plurals in the URL, indicating that the result is always a selection from among them. Each ZINC URL may specify only one resource. The URL syntax here covers both the web pages and the API. We currently support the following resources:

Resource	Is a set of	Approximate Number	Example use of this resource when the answer to your question is: a) a list of these things b) one of these things, or c) things derived from a single one of these things.
substances	molecules	200,000,000	a) purchasable compounds [1] b) ZINC ID 53 [2] c) All genes hit by compound ZINC597013 [3]
catalogs	vendor and annotated catalogs	400	a) catalogs whose members are biogenic (but see also endogenous, metabolite) [4] b) The ChEMBL20 catalog [5] c) Items in the DrugBank FDA catalogs [6] Interestingly, this shows clearly when a DrugBank ID has been expanded into multiple ZINC IDs.
genes	UniProt Gene Symbols	2800	a) All Class A GPCR genes [7] b) The BTK gene [8] c) SEA Predicted ligands for 5-HT2A [9]
catitems	What they are called in the source catalog	1 billion	a) All molecules where the original supplier code begins with B1234 [10] b) N.B. There is no unique key for supplier codes, so you cannot necessairily select one. The purpose of the catitem code allows you to write queries that originate in another catalog Items in the HMDB database, where the catalog code starts with HMDB1 and the gene it is active against starts with ADR. [11] Compounds sold by Frontier, beginning with B123 and containing a pyridine ring. [12]
protomers	3D representations	6 million and growing	various protonated and tautomerized forms of the molecule in 3D
targets	UniProt accession codes	3800	species-specific molecular targets
activities	Observed	220,000	about individual observations of biological activity of small molecules.
clusterreps	Cluster representatives	3900	about chemical diversity of ligands for genes
clusters	Clustered compounds by gene	220,000	about compounds for genes organized by chemotype.
majorclasses	asdf asdf	15	asdfasfd sadf
subclasses	asdf asdf	44	asdfasfd sadf
organisms	asdf asdf	5	asdfasfd sadf
tools	asdf asdf	10,000	Reserved for future use
ecfp4s	lala	100,000,000	fingerprints
predictions	SEA predictions	1 billion	sea
atccodes	atc codes	1500	atccodes
generelations	gene_relations	250,000	gene_relations
observations	obs	280,000	obs

Historical note: In ZINC 12, the reference-table was always substances, and thus the result of any query was always a set of molecules. A few reports such as vendor and target listings were available via the webpages, but were not supported by the API. This is a substantial change that appeared first in ZINC 15.