2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one

C161H104F30N20O16 — CID 162042872

About 2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one

2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one (PubChem CID 162042872) has the molecular formula C161H104F30N20O16 and a molecular weight of 3144.67 g/mol. Its IUPAC name is 2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one.

Molecular Properties

• Compound Name: 2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one
• PubChem CID: 162042872
• Molecular Formula: C161H104F30N20O16
• Molecular Weight: 3144.67 g/mol
• Exact Mass: 3142.75
• IUPAC Name: 2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one
• SMILES: Cc1ccc(N)c(N2C(=O)c3ccc(C(c4ccc5c(c4)C(=O)N(c4cc(C)ccc4N)C5=O)(C(F)(F)F)C(F)(F)F)cc3C2=O)c1.Cc1ccc2nc(-c3ccc(C(c4ccc(-c5nc6ccc(C)cc6[nH]5)c(C(=O)O)c4)(C(F)(F)F)C(F)(F)F)cc3C(=O)O)[nH]c2c1.Cc1ccc2nc(-c3ccc(C(c4ccc(-c5nc6ccc(C)cc6[nH]5)cc4)(C(F)(F)F)C(F)(F)F)cc3)[nH]c2c1.Cc1ccc2nc3n(c2c1)C(=O)c1cc(C(c2ccc4c(c2)C(=O)n2c-4nc4ccc(C)cc42)(C(F)(F)F)C(F)(F)F)ccc1-3.Nc1ccc(-c2ccc(N)c(N)c2)cc1N.O=C1OC(=O)c2cc(C(c3ccc4c(c3)C(=O)OC4=O)(C(F)(F)F)C(F)(F)F)ccc21
• InChI: InChI=1S/2C33H22F6N4O4.C33H18F6N4O2.C31H22F6N4.C19H6F6O6.C12H14N4/c1-15-3-9-23(40)25(11-15)42-27(44)19-7-5-17(13-21(19)29(42)46)31(32(34,35)36,33(37,38)39)18-6-8-20-22(14-18)30(47)43(28(20)45)26-12-16(2)4-10-24(26)41;1-15-3-9-23-25(11-15)42-27(40-23)19-7-5-17(13-21(19)29(44)45)31(32(34,35)36,33(37,38)39)18-6-8-20(22(14-18)30(46)47)28-41-24-10-4-16(2)12-26(24)43-28;1-15-3-9-23-25(11-15)42-27(40-23)19-7-5-17(13-21(19)29(42)44)31(32(34,35)36,33(37,38)39)18-6-8-20-22(14-18)30(45)43-26-12-16(2)4-10-24(26)41-28(20)43;1-17-3-13-23-25(15-17)40-27(38-23)19-5-9-21(10-6-19)29(30(32,33)34,31(35,36)37)22-11-7-20(8-12-22)28-39-24-14-4-18(2)16-26(24)41-28;20-18(21,22)17(19(23,24)25,7-1-3-9-11(5-7)15(28)30-13(9)26)8-2-4-10-12(6-8)16(29)31-14(10)27;13-9-3-1-7(5-11(9)15)8-2-4-10(14)12(16)6-8/h3-14H,40-41H2,1-2H3;3-14H,1-2H3,(H,40,42)(H,41,43)(H,44,45)(H,46,47);3-14H,1-2H3;3-16H,1-2H3,(H,38,40)(H,39,41);1-6H;1-6H,13-16H2
• InChIKey: YXMXLCFDUAIMLD-UHFFFAOYSA-N
• XLogP: 36.63
• TPSA: 576.72 Ų
• H-Bond Donors: 12
• H-Bond Acceptors: 28
• Rotatable Bonds: 19
• Heavy Atoms: 227
• Complexity: —

Lipinski Rule of Five

4 violations

Rule	Value
MW ≤ 500	3144.67
LogP ≤ 5	36.63
H-Bond Donors ≤ 5	12
H-Bond Acceptors ≤ 10	28

Computed Properties (RDKit)

• Structural Alerts: {'alert_name': 'aniline', 'substructure': 'N/A'}, {'alert_name': 'beta-keto/anhydride', 'substructure': 'N/A'}, {'alert_name': 'phthalimide', 'substructure': 'N/A'}

Frequently Asked Questions

What is the IUPAC name of 2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one?

The IUPAC name of 2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one (CID 162042872) is 2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one.

What is the SMILES notation for 2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one?

The canonical SMILES for 2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one is Cc1ccc(N)c(N2C(=O)c3ccc(C(c4ccc5c(c4)C(=O)N(c4cc(C)ccc4N)C5=O)(C(F)(F)F)C(F)(F)F)cc3C2=O)c1.Cc1ccc2nc(-c3ccc(C(c4ccc(-c5nc6ccc(C)cc6[nH]5)c(C(=O)O)c4)(C(F)(F)F)C(F)(F)F)cc3C(=O)O)[nH]c2c1.Cc1ccc2nc(-c3ccc(C(c4ccc(-c5nc6ccc(C)cc6[nH]5)cc4)(C(F)(F)F)C(F)(F)F)cc3)[nH]c2c1.Cc1ccc2nc3n(c2c1)C(=O)c1cc(C(c2ccc4c(c2)C(=O)n2c-4nc4ccc(C)cc42)(C(F)(F)F)C(F)(F)F)ccc1-3.Nc1ccc(-c2ccc(N)c(N)c2)cc1N.O=C1OC(=O)c2cc(C(c3ccc4c(c3)C(=O)OC4=O)(C(F)(F)F)C(F)(F)F)ccc21.

What is the InChIKey of 2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one?

The InChIKey is YXMXLCFDUAIMLD-UHFFFAOYSA-N. The full InChI is InChI=1S/2C33H22F6N4O4.C33H18F6N4O2.C31H22F6N4.C19H6F6O6.C12H14N4/c1-15-3-9-23(40)25(11-15)42-27(44)19-7-5-17(13-21(19)29(42)46)31(32(34,35)36,33(37,38)39)18-6-8-20-22(14-18)30(47)43(28(20)45)26-12-16(2)4-10-24(26)41;1-15-3-9-23-25(11-15)42-27(40-23)19-7-5-17(13-21(19)29(44)45)31(32(34,35)36,33(37,38)39)18-6-8-20(22(14-18)30(46)47)28-41-24-10-4-16(2)12-26(24)43-28;1-15-3-9-23-25(11-15)42-27(40-23)19-7-5-17(13-21(19)29(42)44)31(32(34,35)36,33(37,38)39)18-6-8-20-22(14-18)30(45)43-26-12-16(2)4-10-24(26)41-28(20)43;1-17-3-13-23-25(15-17)40-27(38-23)19-5-9-21(10-6-19)29(30(32,33)34,31(35,36)37)22-11-7-20(8-12-22)28-39-24-14-4-18(2)16-26(24)41-28;20-18(21,22)17(19(23,24)25,7-1-3-9-11(5-7)15(28)30-13(9)26)8-2-4-10-12(6-8)16(29)31-14(10)27;13-9-3-1-7(5-11(9)15)8-2-4-10(14)12(16)6-8/h3-14H,40-41H2,1-2H3;3-14H,1-2H3,(H,40,42)(H,41,43)(H,44,45)(H,46,47);3-14H,1-2H3;3-16H,1-2H3,(H,38,40)(H,39,41);1-6H;1-6H,13-16H2.

What are the key properties of 2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one?

2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one has a molecular weight of 3144.67 g/mol, XLogP of 36.63, 19 rotatable bonds, 12 hydrogen bond donors, and 28 hydrogen bond acceptors.

Where does this data come from?

All data for 2-(2-amino-5-methylphenyl)-5-[2-[2-(2-amino-5-methylphenyl)-1,3-dioxoisoindol-5-yl]-1,1,1,3,3,3-hexafluoropropan-2-yl]isoindole-1,3-dione;5-[2-[3-carboxy-4-(6-methyl-1H-benzimidazol-2-yl)phenyl]-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-(6-methyl-1H-benzimidazol-2-yl)benzoic acid;4-(3,4-diaminophenyl)benzene-1,2-diamine;5-[2-(1,3-dioxo-2-benzofuran-5-yl)-1,1,1,3,3,3-hexafluoropropan-2-yl]-2-benzofuran-1,3-dione;2-[4-[1,1,1,3,3,3-hexafluoro-2-[4-(6-methyl-1H-benzimidazol-2-yl)phenyl]propan-2-yl]phenyl]-6-methyl-1H-benzimidazole;2-[1,1,1,3,3,3-hexafluoro-2-(8-methyl-11-oxoisoindolo[2,1-a]benzimidazol-2-yl)propan-2-yl]-8-methylisoindolo[2,3-a]benzimidazol-11-one is sourced from PubChem (CID 162042872), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).