Fig. 23

Differences between PubChem-standardized and InChI-derived structures—tautomeric preference in functional groups. Examples for tautomeric preferences of characteristic functional groups. a Amide (SID 75764); b Thioamide (SID 108898); c Amidine (SID 132494); d Functional groups and their preferences can occur simultaneously (SID 5856091). In all cases: (i) InChI-derived structure; (ii) structure after subsequent PubChem standardization