Table 3.

Various rulesets for medicinal chemistry along with key results PAINs, Brenk and Lead-likeness rules.

Ruleset	Key Results	Criteria
PAINS	Identifies frequent hitters and promiscuous compounds that can interfere with assay results or exhibit undesirable properties.	- Consists of substructural patterns associated with problematic behavior. - Alerts against compounds with potential for false positives or misleading data. - Does not guarantee drug-likeness.
Brenk	Filters out compounds that violate certain chemical rules associated with undesirable properties.	- Based on chemical fragments and structural motifs. - Identifies compounds with potential for toxicity, reactivity, or instability. - Does not ensure drug-like properties.
Leadlikeness	Screens compounds based on structural features commonly found in lead compounds.	- Identifies compounds with desirable properties for further development. - Considers molecular weight, lipophilicity, and structural complexity. - Aims to prioritize compounds with lead-like characteristics.