What is loaded in ZINC?

Starting in 2004, we loaded molecules that pass basic Filtering rules and are also under 500 Daltons.

By 2008, we started loading molecules that were biologically active (as annotated in public databases) up to 800 Daltons, with very few filtering rules, since biologically active often means interesting regardless of hot chemical functionality or value as a lead.

By 2014, we realized that we had been omitting an important subclass of compounds that are biologically active, exceed the original 2004 rules, but are found in commercially available and not annotated catalogs. What this means, for instance, is that we used to load maltotriose (mwt 505) if it was in an annotated database such as ChEBI, but failed to load it from Sigma Aldrich. As a result, compounds over 500 Daltons that are commercially available exceed the 2004 filter

(incomplete, working)