Wikipedia:  

Guanine

2-Amino-6-hydroxypurine; CI Natural white 1; Hypoxanthine, 2-amino-; Guanin; Mearlmaid; Guanine enol; GUANINE; 2-Aminohypoxanthine; 2-Amino-6-purinol; 6H-Purin-6-one, 2-amino-1,7-dihydro-; C.I. Natural White 1
Molecular Formula
C5 H5 N5 O
Natural Isotopic Abundance Mass
151.1261000000
Mono-Isotopic Molecular Masses
C12N14:   151.049409809
C13N14:   156.066183998
C12N15:   156.034584275
C13N15:   161.0513584636
Guanine image
Guanine
InCHi String:
InChI=1S/C5H5N5O/c6-5-9-3-2(4(11)10-5)7-1-8-3/h1H,(H4,6,7,8,9,10,11)

isomeric and canonical SMILES:
C1=NC2=C(N1)C(=O)N=C(N2)N


IUPAC: IUPAC traditional: IUPAC cas: IUPAC openeye: IUPAC systematic
2-amino-3,7-dihydropurin-6-one



PubChem Substance (SID):   85164931   149248   3541
PubChem Compound (CID):   764
KEGG: Compound ID   C00242
CAS Registry IDs:   11006-44-3   15986-36-4   37432-34-1   492-33-1   54435-87-9   69257-39-2   73-40-5   8039-79-0
PDB Chemical Component   GUN
Miscellaneous Databases and IDs:   CHEBI 16235   HSDB 2127   EINECS 200-799-8

Reference data were obtained primarily from the PubChem database.

Three dimensional molecular rendering uses Jmol.