We revoked 12M ZINC compounds from Pubchem this week. We thought you might like to know more about this. If so, read on...

ZINC includes about 12M make-on-demand compounds. These are not just mindless virtual combichem. The companies involved (Enamine is the biggest) predict likelihood of synthetic success by systematically making some of the compounds. The success rate for acquisition of these make-on-demands is often as high as the on-the-shelf compounds (perhaps 60-80%, varies a lot) because of depletion, bookkeeping errors, out of date catalogs, etc. Thus it is ZINC's policy to include make-on-demands in ZINC. Still, Pubchem's rules require that compounds have been made somewhere before they be included. Thus the recent Pubchem revocation is in response, which I was happy to accommodate. Correspondingly, ZINC offers make-on-demand-free "leads-now" and "fragments-now" subsets for the "shelfers".

ZINC is supposed to serve the community, and I am happy to accommodate, when I learn what people want.