Chart of CNS med chem mnemonic rules

[S.J.B.]

References can be found here.

 

[sekio]

Some definitions for the less academic:
PSA: polar surface area
TPSA: total polar surface area
SASA: solvent accessible surface area
MW: molecular weight
HBD: hydrogen bond donors
HBA: hydrogen bond acceptor
HAC: heavy atom count (number of non-hydrogen atoms)
NRotB: number of rotatable bonds
NArR: number of aromatic rings
XlogP / ClogP: calculated logarithm of partition coefficient
XlogD / ClogD: calculated logarithm of partition coefficient at a certain pH


also

https://www.criver.com/sites/default/files/resource-files/DS-medicinal-chemistry-reference-sheet.pdf

 

[clubcard]

For a decade, Pfizer would not even try to develop any drug that did not meet RO5. It has to be said that the attrition-rate among candidates IS substantially lower. As sekio points out, their are other 'rules' that provide a 'druglikeness' value. One of the more obscure ones involves how achiral a compound is. Well, the way it was put to me was that a telephone directory might be 2000 pages but they use minimal space because the pages tessellate. Make 2000 paper hats and they will occupy significantly more space..
A drug that occupies more space but doesn't have to many rotatable bonds is more 'druglike'.

I've seen Javascripts that take a SMILES string and provide a 'druglikeness' value. Not something I would trust, but if something failed, I would at least look again.

Don't forget that the number of possible compounds with a MW under 300 is simply massive. We have only just grazed the surface. I have a friend who is a virologist and I just cannot work unless I can see the molecule in my head. Lucky I can manage the RO5!