PubChem, released in 2004, provides information on the biological activities of small molecules. It is a component of NIH's Molecular Libraries Roadmap Initiative. PubChem is organized as three linked databases within the NCBI's Entrez information retrieval system. These are PubChem Substance, PubChem Compound, and PubChem BioAssay.
First you need to enable extensions, instructions are here.
After you have downloaded the extension from here simply double click and install and it is ready to use.
If a page contains a drug name (this page describes AOX1 substrates), select the name and right click (or control click) and an option appears to search for the highlighted drug on PubChem.
Click the “Search for ... on PubChem” and a page will be opened in another tab showing the search results from PubChem.
If you go to the Safari preferences and select the “Extensions” tab you can alter any preferences that may be available for a particular extension. In this case you can use this extension to search three different PubChem Databases PubChem compound records comprise a non-redundant set of standardized and validated chemical structures. A compound record may link to more than one PubChem Substance record, if different depositors supplied the same structure. Chemical names shown in PubChem Compound records are a composite derived from all linked substances, with default ranking of names by weighted frequency of use. PubChem Substance records contain substance information electronically submitted to PubChem by depositors. This includes any chemical structure information submitted, as well as chemical names, comments, and links to the depositor's web site. The PubChem BioAssay Database contains BioActivity screens of chemical substances described in PubChem Substance. It provides searchable descriptions of each BioAssay, including descriptions of the conditions and readouts specific to that screening procedure.
You can also choose how you want the results displayed, whether in a new window or the current window etc.