Rule of three

{
  "id": "MLC-T-CHM-010453",
  "term": "Rule of three",
  "field": "Chemistry",
  "definition": "A set of guidelines used in fragment-based lead discovery to define a chemical fragment suitable for screening against a biological target. These criteria state that a fragment should have a molecular weight less than 300 daltons, a maximum of three hydrogen bond donors, and a maximum of three hydrogen bond acceptors. The calculated logarithm of the octanol-water partition coefficient (cLogP) should also be less than or equal to three.",
  "subject": "Chemistry and Human Health",
  "see_also": [
    "fragment-based lead discovery",
    "fragment",
    "hit",
    "lead",
    "molecular descriptor"
  ],
  "references": [
    "PAC, 2013, 85, 1725. 'Glossary of terms used in medicinal chemistry. Part II (IUPAC Recommendations 2013)' on page 1750 (https://doi.org/10.1351/PAC-REC-12-11-23)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/rule-of-three/"
}