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Pyrrolysine

Athanor · official

C12H21N3O3 · 255.31 g/mol

IUPAC name: (2R)-2-amino-6-[[(2R,3R)-3-methyl-3,4-dihydro-2H-pyrrole-2-carbonyl]amino]hexanoic acid

Also called Pyl, O, the 22nd amino acid

Open in Athanor
The structure of Pyrrolysine
Drawn from its SMILES with RDKit

Names and identifiers

IUPAC name
(2R)-2-amino-6-[[(2R,3R)-3-methyl-3,4-dihydro-2H-pyrrole-2-carbonyl]amino]hexanoic acid
Synonyms
Pyl, O, the 22nd amino acid
Molecular formula
C12H21N3O3
Empirical formula
C4H7NO
Molecular weight
255.31 g/mol
Exact mass
255.15829
CAS number
448235-52-7
PubChem CID
20831703
Canonical SMILES
CC1CC=NC1C(=O)NCCCCC(C(=O)O)N
Isomeric SMILES
C[C@@H]1CC=N[C@H]1C(=O)NCCCC[C@H](C(=O)O)N
InChI
InChI=1S/C12H21N3O3/c1-8-5-7-14-10(8)11(16)15-6-3-2-4-9(13)12(17)18/h7-10H,2-6,13H2,1H3,(H,15,16)(H,17,18)/t8-,9-,10-/m1/s1
InChIKey
ZFOMKMMPBOQKMC-OPRDCNLKSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Calculated

Heavy atoms
18
Rings
1
Aromatic rings
0
Fraction sp³ carbons (Fsp3)
0.75
H-bond donors
3
H-bond acceptors
4 computed here · PubChem 5
Rotatable bonds
7
TPSA (Ų)
104.8 computed here · PubChem 105
Formal charge
0
XLogP3
-2.8 PubChem
Complexity
331 PubChem
Stereocenters
3 definedCIP: C2: R · C6: R · C14: R
Double-bond geometry
None specified
Point group
C1 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

  • C56.45%
  • H8.29%
  • N16.46%
  • O18.80%

Isotope pattern

100%255.15814%256.1611.6%257.163258.166

Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.

Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.

Predicted

log P
0.16 Crippen (Wildman and Crippen 1999)
log S (water solubility)
-1.06 ESOL (Delaney 2004), log mol/L
Synthetic accessibility
3.79 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

  • Molecular weight ≤ 500: 255.32
  • log P ≤ 5 (Crippen): 0.16
  • H-bond donors ≤ 5: 3
  • H-bond acceptors ≤ 10: 4

Passes all four rules.

¹³C NMR shifts, predicted

Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.

Safety

No GHS hazard classification was found in the sources.

Always read the supplier’s safety data sheet before working with it.

Literature

Reading PubChem, OpenAlex and GSRS…

Bioactivity

Reading ChEMBL…

References

  1. ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
  2. ·Literature on PubChem

Data last updated 2026-10-14.