I am tired of searching compounds online. So far, more than 140 Millons substances have been registered for CAS registry number. However, it doesn’t mean CAS has covered all the compounds. In fact, at least three identifiers have been used to let someone find the compounds’ information online.

The first one is CAS registry number. This number is quiet useful to buy standards. However, it’s not free to get access to the full list of CAS registry number. Furthormore, this number is for substance, which is different from compounds. For example, <a href=“https://www.ncbi.nlm.nih.gov/p