4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile

C126H144F7N27O9 — CID 158545700

About 4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile

4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile (PubChem CID 158545700) has the molecular formula C126H144F7N27O9 and a molecular weight of 2313.70 g/mol. Its IUPAC name is 4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile.

Molecular Properties

• Compound Name: 4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile
• PubChem CID: 158545700
• Molecular Formula: C126H144F7N27O9
• Molecular Weight: 2313.70 g/mol
• Exact Mass: 2312.15
• IUPAC Name: 4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile
• SMILES: C=C(F)C(=O)N1CCN(c2c(C#N)c(OC[C@@H]3CCCN3C)nc3c2CCN(c2c(C)ccc4[nH]ncc24)C3)C[C@@H]1C.C=C(F)C(=O)N1CCN(c2c(C#N)c(OC[C@@H]3CCCN3C)nc3c2CCN(c2cccc4cc(O)ccc24)C3)C[C@@H]1C.C=C(F)C(=O)N1CCN(c2c(C#N)c(OC[C@@H]3CCCN3C)nc3c2CCN(c2cccc4cnccc24)C3)C[C@@H]1C.C=C(F)C(=O)N1CCN(c2c(C#N)c(OC[C@@H]3CCCN3C)nc3c2CCN(c2ccccc2C(F)(F)F)C3)C[C@@H]1C
• InChI: InChI=1S/C33H37FN6O3.C32H36FN7O2.C31H37FN8O2.C30H34F4N6O2/c1-21-18-39(14-15-40(21)33(42)22(2)34)31-27-11-13-38(30-8-4-6-23-16-25(41)9-10-26(23)30)19-29(27)36-32(28(31)17-35)43-20-24-7-5-12-37(24)3;1-21-18-39(14-15-40(21)32(41)22(2)33)30-26-10-13-38(29-8-4-6-23-17-35-11-9-25(23)29)19-28(26)36-31(27(30)16-34)42-20-24-7-5-12-37(24)3;1-19-7-8-26-25(15-34-36-26)28(19)38-11-9-23-27(17-38)35-30(42-18-22-6-5-10-37(22)4)24(14-33)29(23)39-12-13-40(20(2)16-39)31(41)21(3)32;1-19-16-39(13-14-40(19)29(41)20(2)31)27-22-10-12-38(26-9-5-4-8-24(26)30(32,33)34)17-25(22)36-28(23(27)15-35)42-18-21-7-6-11-37(21)3/h4,6,8-10,16,21,24,41H,2,5,7,11-15,18-20H2,1,3H3;4,6,8-9,11,17,21,24H,2,5,7,10,12-15,18-20H2,1,3H3;7-8,15,20,22H,3,5-6,9-13,16-18H2,1-2,4H3,(H,34,36);4-5,8-9,19,21H,2,6-7,10-14,16-18H2,1,3H3/t2*21-,24-;20-,22-;19-,21-/m0000/s1
• InChIKey: HPBVONRGEKMMCL-SMMHSMBMSA-N
• XLogP: 16.65
• TPSA: 365.56 Ų
• H-Bond Donors: 2
• H-Bond Acceptors: 31
• Rotatable Bonds: 24
• Heavy Atoms: 169
• Complexity: —

Lipinski Rule of Five

3 violations

Rule	Value
MW ≤ 500	2313.70
LogP ≤ 5	16.65
H-Bond Donors ≤ 5	2
H-Bond Acceptors ≤ 10	31

Computed Properties (RDKit)

• Structural Alerts: {'alert_name': 'Michael_acceptor_1', 'substructure': 'N/A'}

Frequently Asked Questions

What is the IUPAC name of 4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile?

The IUPAC name of 4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile (CID 158545700) is 4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile.

What is the SMILES notation for 4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile?

The canonical SMILES for 4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile is C=C(F)C(=O)N1CCN(c2c(C#N)c(OC[C@@H]3CCCN3C)nc3c2CCN(c2c(C)ccc4[nH]ncc24)C3)C[C@@H]1C.C=C(F)C(=O)N1CCN(c2c(C#N)c(OC[C@@H]3CCCN3C)nc3c2CCN(c2cccc4cc(O)ccc24)C3)C[C@@H]1C.C=C(F)C(=O)N1CCN(c2c(C#N)c(OC[C@@H]3CCCN3C)nc3c2CCN(c2cccc4cnccc24)C3)C[C@@H]1C.C=C(F)C(=O)N1CCN(c2c(C#N)c(OC[C@@H]3CCCN3C)nc3c2CCN(c2ccccc2C(F)(F)F)C3)C[C@@H]1C.

What is the InChIKey of 4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile?

The InChIKey is HPBVONRGEKMMCL-SMMHSMBMSA-N. The full InChI is InChI=1S/C33H37FN6O3.C32H36FN7O2.C31H37FN8O2.C30H34F4N6O2/c1-21-18-39(14-15-40(21)33(42)22(2)34)31-27-11-13-38(30-8-4-6-23-16-25(41)9-10-26(23)30)19-29(27)36-32(28(31)17-35)43-20-24-7-5-12-37(24)3;1-21-18-39(14-15-40(21)32(41)22(2)33)30-26-10-13-38(29-8-4-6-23-17-35-11-9-25(23)29)19-28(26)36-31(27(30)16-34)42-20-24-7-5-12-37(24)3;1-19-7-8-26-25(15-34-36-26)28(19)38-11-9-23-27(17-38)35-30(42-18-22-6-5-10-37(22)4)24(14-33)29(23)39-12-13-40(20(2)16-39)31(41)21(3)32;1-19-16-39(13-14-40(19)29(41)20(2)31)27-22-10-12-38(26-9-5-4-8-24(26)30(32,33)34)17-25(22)36-28(23(27)15-35)42-18-21-7-6-11-37(21)3/h4,6,8-10,16,21,24,41H,2,5,7,11-15,18-20H2,1,3H3;4,6,8-9,11,17,21,24H,2,5,7,10,12-15,18-20H2,1,3H3;7-8,15,20,22H,3,5-6,9-13,16-18H2,1-2,4H3,(H,34,36);4-5,8-9,19,21H,2,6-7,10-14,16-18H2,1,3H3/t2*21-,24-;20-,22-;19-,21-/m0000/s1.

What are the key properties of 4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile?

4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile has a molecular weight of 2313.70 g/mol, XLogP of 16.65, 24 rotatable bonds, 2 hydrogen bond donors, and 31 hydrogen bond acceptors.

Where does this data come from?

All data for 4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(6-hydroxynaphthalen-1-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-isoquinolin-5-yl-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-7-(5-methyl-1H-indazol-4-yl)-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile;4-[(3S)-4-(2-fluoroprop-2-enoyl)-3-methylpiperazin-1-yl]-2-[[(2S)-1-methylpyrrolidin-2-yl]methoxy]-7-[2-(trifluoromethyl)phenyl]-6,8-dihydro-5H-1,7-naphthyridine-3-carbonitrile is sourced from PubChem (CID 158545700), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).