1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate

C108H159Br3I2N20O13 — CID 161132988

IUPAC1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate
SMILESCC(=O)c1cc(Br)cnc1N1CC[C@@H](NC2CCCCC2)[C@H](O)C1.COC(=O)c1cc(C)cnc1N1CC[C@@H](NC2CCCCC2)[C@H](O)C1.COC(=O)c1cc(I)cnc1N1CCC(NC2CCCCC2)C(O)C1.COC(=O)c1cc(I)cnc1N1CCC(NC2CCCCC2)C(OC)C1.[H]/N=C/c1cc(Br)cnc1N1CCC(NC2CCCCC2)C(O)C1.[H]/N=C/c1cc(Br)cnc1N1CCC(NC2CCCCC2)C(O)C1
InChIInChI=1S/C19H28IN3O3.C19H29N3O3.C18H26BrN3O2.C18H26IN3O3.2C17H25BrN4O/c1-25-17-12-23(9-8-16(17)22-14-6-4-3-5-7-14)18-15(19(24)26-2)10-13(20)11-21-18;1-13-10-15(19(24)25-2)18(20-11-13)22-9-8-16(17(23)12-22)21-14-6-4-3-5-7-14;1-12(23)15-9-13(19)10-20-18(15)22-8-7-16(17(24)11-22)21-14-5-3-2-4-6-14;1-25-18(24)14-9-12(19)10-20-17(14)22-8-7-15(16(23)11-22)21-13-5-3-2-4-6-13;2*18-13-8-12(9-19)17(20-10-13)22-7-6-15(16(23)11-22)21-14-4-2-1-3-5-14/h10-11,14,16-17,22H,3-9,12H2,1-2H3;10-11,14,16-17,21,23H,3-9,12H2,1-2H3;9-10,14,16-17,21,24H,2-8,11H2,1H3;9-10,13,15-16,21,23H,2-8,11H2,1H3;2*8-10,14-16,19,21,23H,1-7,11H2/b;;;;2*19-9+/t;2*16-,17-;;;/m.11.../s1
InChIKeyUMKZYNCUPBERSI-CFDVUOQBSA-N
MW2439.11 g/mol
LogP15.68
Rot. Bonds25

About 1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate

1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate (PubChem CID 161132988) has the molecular formula C108H159Br3I2N20O13 and a molecular weight of 2439.11 g/mol. Its IUPAC name is 1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate.

Molecular Properties

Compound Name1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate
PubChem CID161132988
Molecular FormulaC108H159Br3I2N20O13
Molecular Weight2439.11 g/mol
Exact Mass2434.80
IUPAC Name1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate
SMILESCC(=O)c1cc(Br)cnc1N1CC[C@@H](NC2CCCCC2)[C@H](O)C1.COC(=O)c1cc(C)cnc1N1CC[C@@H](NC2CCCCC2)[C@H](O)C1.COC(=O)c1cc(I)cnc1N1CCC(NC2CCCCC2)C(O)C1.COC(=O)c1cc(I)cnc1N1CCC(NC2CCCCC2)C(OC)C1.[H]/N=C/c1cc(Br)cnc1N1CCC(NC2CCCCC2)C(O)C1.[H]/N=C/c1cc(Br)cnc1N1CCC(NC2CCCCC2)C(O)C1
InChIInChI=1S/C19H28IN3O3.C19H29N3O3.C18H26BrN3O2.C18H26IN3O3.2C17H25BrN4O/c1-25-17-12-23(9-8-16(17)22-14-6-4-3-5-7-14)18-15(19(24)26-2)10-13(20)11-21-18;1-13-10-15(19(24)25-2)18(20-11-13)22-9-8-16(17(23)12-22)21-14-6-4-3-5-7-14;1-12(23)15-9-13(19)10-20-18(15)22-8-7-16(17(24)11-22)21-14-5-3-2-4-6-14;1-25-18(24)14-9-12(19)10-20-17(14)22-8-7-15(16(23)11-22)21-13-5-3-2-4-6-13;2*18-13-8-12(9-19)17(20-10-13)22-7-6-15(16(23)11-22)21-14-4-2-1-3-5-14/h10-11,14,16-17,22H,3-9,12H2,1-2H3;10-11,14,16-17,21,23H,3-9,12H2,1-2H3;9-10,14,16-17,21,24H,2-8,11H2,1H3;9-10,13,15-16,21,23H,2-8,11H2,1H3;2*8-10,14-16,19,21,23H,1-7,11H2/b;;;;2*19-9+/t;2*16-,17-;;;/m.11.../s1
InChIKeyUMKZYNCUPBERSI-CFDVUOQBSA-N
XLogP15.68
TPSA423.01 Ų
H-Bond Donors13
H-Bond Acceptors33
Rotatable Bonds25
Heavy Atoms146
Complexity—

Lipinski Rule of Five

4 violations

RuleValue
MW ≤ 5002439.11
LogP ≤ 515.68
H-Bond Donors ≤ 513
H-Bond Acceptors ≤ 1033

Computed Properties (RDKit)

Structural Alerts{'alert_name': '>_2_ester_groups', 'substructure': 'N/A'}, {'alert_name': 'imine_1', 'substructure': 'N/A'}, {'alert_name': 'iodine', 'substructure': 'N/A'}

Analyze 1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate with MolForge

Explore ADMET properties, 3D molecular structure, drug-likeness score, and discover similar compounds using our AI-powered platform.

Launch Full Analysis

Related Compounds

Methyl 5-bromo-2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]pyridine-3-carboxylate
CID 60156214
methyl 5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]pyridine-3-carboxylate
CID 73295685
Methyl 5-bromo-2-[3-hydroxy-4-[(2-methoxycyclohexyl)amino]piperidin-1-yl]pyridine-3-carboxylate
CID 118263634
CID 118264113
CID 118264113
Methyl 5-bromo-2-[4-(cyclohexylamino)-3,5-dihydroxypiperidin-1-yl]pyridine-3-carboxylate
CID 118263638
methyl 5-bromo-6-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]pyridine-3-carboxylate
CID 118266933
Methyl 5-bromo-6-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]pyridine-3-carboxylate
CID 118267238
Ethyl 5-bromo-2-[4-(cyclohexylamino)-3-(hydroxymethyl)piperidin-1-yl]pyridine-3-carboxylate;ethyl 5-chloro-2-[4-(cyclohexylamino)-3-(hydroxymethyl)piperidin-1-yl]pyridine-3-carboxylate;methyl 5-bromo-2-[3-(cyclohexylamino)azetidin-1-yl]pyridine-3-carboxylate;methyl 5-bromo-2-[4-(cyclohexylamino)-3-(hydroxymethyl)piperidin-1-yl]pyridine-3-carboxylate;methyl 5-bromo-2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]pyridine-3-carboxylate;methyl 5-chloro-2-[4-(cyclohexylamino)-3-(hydroxymethyl)piperidin-1-yl]pyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)piperidin-1-yl]-5-fluoropyridine-3-carboxylate
CID 157366941
2-bromo-3-methyl-5-(oxiran-2-yl)pyridine;6-bromo-5-methylpyridine-3-carbaldehyde;1-(6-bromo-5-methyl-3-pyridinyl)-2-(2-hydroxyethylamino)ethanol;tert-butyl 2-[6-(benzhydrylideneamino)-5-methyl-3-pyridinyl]morpholine-4-carboxylate;tert-butyl N-[2-(6-bromo-5-methyl-3-pyridinyl)-2-hydroxyethyl]-N-(2-hydroxyethyl)carbamate;tert-butyl 2-(6-bromo-5-methyl-3-pyridinyl)morpholine-4-carboxylate;methanamine;methane
CID 157394715
bis([1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-yl]methanol);3-O-ethyl 5-O-methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-6-methylpyridine-3,5-dicarboxylate;methyl 5-bromo-2-[4-(cycloheptylamino)-3-methoxycarbonylpiperidin-1-yl]pyridine-3-carboxylate;methyl 5-bromo-2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]pyridine-3-carboxylate;methyl 5-bromo-2-[4-(cyclopentylamino)-3-methoxycarbonylpiperidin-1-yl]pyridine-3-carboxylate
CID 157584327
ethyl 5-bromo-2-[4-[[(2S)-2-hydroxycyclohexyl]amino]piperidin-1-yl]pyridine-3-carboxylate;ethyl 4-chloro-2-[4-[[(2R)-2-hydroxycyclohexyl]amino]piperidin-1-yl]-6-methylpyridine-3-carboxylate;methyl 5-bromo-2-[4-(cyclohexylamino)piperidin-1-yl]pyridine-3-carboxylate;methyl 5-bromo-2-[4-[[(2R)-2-hydroxycyclohexyl]amino]piperidin-1-yl]pyridine-3-carboxylate;methyl 5-bromo-2-[4-[(3-hydroxycyclohexyl)amino]piperidin-1-yl]pyridine-3-carboxylate;methyl 5-bromo-2-[4-[(2-hydroxycyclopentyl)amino]piperidin-1-yl]pyridine-3-carboxylate;methyl 5-bromo-2-[4-(2-hydroxyethylamino)piperidin-1-yl]pyridine-3-carboxylate
CID 158000688
1-[5-bromo-2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-N-cyclohexylpiperidin-4-amine);1-(3-bromo-5-methyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol;[1-(3-bromo-5-methyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-yl]methanol;bis(carbon dioxide);ethanol;3-O-ethyl 5-O-methyl 2-[3-(cyclohexylamino)pyrrolidin-1-yl]-6-methylpyridine-3,5-dicarboxylate;methanol
CID 158202469

Frequently Asked Questions

What is the IUPAC name of 1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate?
The IUPAC name of 1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate (CID 161132988) is 1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate.
What is the SMILES notation for 1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate?
The canonical SMILES for 1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate is CC(=O)c1cc(Br)cnc1N1CC[C@@H](NC2CCCCC2)[C@H](O)C1.COC(=O)c1cc(C)cnc1N1CC[C@@H](NC2CCCCC2)[C@H](O)C1.COC(=O)c1cc(I)cnc1N1CCC(NC2CCCCC2)C(O)C1.COC(=O)c1cc(I)cnc1N1CCC(NC2CCCCC2)C(OC)C1.[H]/N=C/c1cc(Br)cnc1N1CCC(NC2CCCCC2)C(O)C1.[H]/N=C/c1cc(Br)cnc1N1CCC(NC2CCCCC2)C(O)C1.
What is the InChIKey of 1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate?
The InChIKey is UMKZYNCUPBERSI-CFDVUOQBSA-N. The full InChI is InChI=1S/C19H28IN3O3.C19H29N3O3.C18H26BrN3O2.C18H26IN3O3.2C17H25BrN4O/c1-25-17-12-23(9-8-16(17)22-14-6-4-3-5-7-14)18-15(19(24)26-2)10-13(20)11-21-18;1-13-10-15(19(24)25-2)18(20-11-13)22-9-8-16(17(23)12-22)21-14-6-4-3-5-7-14;1-12(23)15-9-13(19)10-20-18(15)22-8-7-16(17(24)11-22)21-14-5-3-2-4-6-14;1-25-18(24)14-9-12(19)10-20-17(14)22-8-7-15(16(23)11-22)21-13-5-3-2-4-6-13;2*18-13-8-12(9-19)17(20-10-13)22-7-6-15(16(23)11-22)21-14-4-2-1-3-5-14/h10-11,14,16-17,22H,3-9,12H2,1-2H3;10-11,14,16-17,21,23H,3-9,12H2,1-2H3;9-10,14,16-17,21,24H,2-8,11H2,1H3;9-10,13,15-16,21,23H,2-8,11H2,1H3;2*8-10,14-16,19,21,23H,1-7,11H2/b;;;;2*19-9+/t;2*16-,17-;;;/m.11.../s1.
What are the key properties of 1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate?
1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate has a molecular weight of 2439.11 g/mol, XLogP of 15.68, 25 rotatable bonds, 13 hydrogen bond donors, and 33 hydrogen bond acceptors.
Where does this data come from?
All data for 1-[5-bromo-2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-3-pyridinyl]ethanone;bis(1-(5-bromo-3-methanimidoyl-2-pyridinyl)-4-(cyclohexylamino)piperidin-3-ol);methyl 2-[4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-iodopyridine-3-carboxylate;methyl 2-[(3R,4R)-4-(cyclohexylamino)-3-hydroxypiperidin-1-yl]-5-methylpyridine-3-carboxylate;methyl 2-[4-(cyclohexylamino)-3-methoxypiperidin-1-yl]-5-iodopyridine-3-carboxylate is sourced from PubChem (CID 161132988), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).