(E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one

C178H204ClN21O11S2 — CID 165054726

About (E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one

(E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one (PubChem CID 165054726) has the molecular formula C178H204ClN21O11S2 and a molecular weight of 2913.31 g/mol. Its IUPAC name is (E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one.

Molecular Properties

• Compound Name: (E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one
• PubChem CID: 165054726
• Molecular Formula: C178H204ClN21O11S2
• Molecular Weight: 2913.31 g/mol
• Exact Mass: 2910.52
• IUPAC Name: (E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one
• SMILES: CCCCC(=O)N(Cc1ccc(-c2ccccc2C2=NNNC2)cc1)[C@H](C(=O)C(C)(C)C)C(C)C.CCCCc1nc(Cl)c(C(=O)C(C)(C)C)n1Cc1ccc(-c2ccccc2C2=NCC=N2)cc1.CCCCc1ncc(/C=C(\Cc2cccs2)C(=O)C(C)(C)C)n1Cc1ccc(C(C)=O)cc1.CCCCc1ncc(/C=C(\Cc2cccs2)C(=O)O)n1Cc1ccc(C(=O)C(C)(C)C)cc1.CCCc1nc2c(C)cc(-c3nc4ccccc4n3C)cc2n1Cc1ccc(-c2ccccc2C(=O)C(C)(C)C)cc1.CCOc1nc2cccc(C(=O)C(C)(C)C)c2n1Cc1ccc(-c2ccccc2-c2cn[nH]n2)cc1
• InChI: InChI=1S/C37H38N4O.C29H29N5O2.C29H40N4O2.C28H31ClN4O.C28H34N2O2S.C27H32N2O3S/c1-7-12-33-39-34-24(2)21-27(36-38-30-15-10-11-16-31(30)40(36)6)22-32(34)41(33)23-25-17-19-26(20-18-25)28-13-8-9-14-29(28)35(42)37(3,4)5;1-5-36-28-31-24-12-8-11-23(27(35)29(2,3)4)26(24)34(28)18-19-13-15-20(16-14-19)21-9-6-7-10-22(21)25-17-30-33-32-25;1-7-8-13-26(34)33(27(20(2)3)28(35)29(4,5)6)19-21-14-16-22(17-15-21)23-11-9-10-12-24(23)25-18-30-32-31-25;1-5-6-11-23-32-26(29)24(25(34)28(2,3)4)33(23)18-19-12-14-20(15-13-19)21-9-7-8-10-22(21)27-30-16-17-31-27;1-6-7-10-26-29-18-24(30(26)19-21-11-13-22(14-12-21)20(2)31)16-23(27(32)28(3,4)5)17-25-9-8-15-33-25;1-5-6-9-24-28-17-22(15-21(26(31)32)16-23-8-7-14-33-23)29(24)18-19-10-12-20(13-11-19)25(30)27(2,3)4/h8-11,13-22H,7,12,23H2,1-6H3;6-17H,5,18H2,1-4H3,(H,30,32,33);9-12,14-17,20,27,30,32H,7-8,13,18-19H2,1-6H3;7-10,12-16H,5-6,11,17-18H2,1-4H3;8-9,11-16,18H,6-7,10,17,19H2,1-5H3;7-8,10-15,17H,5-6,9,16,18H2,1-4H3,(H,31,32)/b;;;;23-16+;21-15+/t;;27-;;;/m..0.../s1
• InChIKey: QFMZDIVMKDPSBQ-PJZBTKAJSA-N
• XLogP: 39.99
• TPSA: 395.96 Ų
• H-Bond Donors: 4
• H-Bond Acceptors: 31
• Rotatable Bonds: 52
• Heavy Atoms: 213
• Complexity: —

Lipinski Rule of Five

3 violations

Rule	Value
MW ≤ 500	2913.31
LogP ≤ 5	39.99
H-Bond Donors ≤ 5	4
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 (E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one?

The IUPAC name of (E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one (CID 165054726) is (E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one.

What is the SMILES notation for (E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one?

The canonical SMILES for (E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one is CCCCC(=O)N(Cc1ccc(-c2ccccc2C2=NNNC2)cc1)[C@H](C(=O)C(C)(C)C)C(C)C.CCCCc1nc(Cl)c(C(=O)C(C)(C)C)n1Cc1ccc(-c2ccccc2C2=NCC=N2)cc1.CCCCc1ncc(/C=C(\Cc2cccs2)C(=O)C(C)(C)C)n1Cc1ccc(C(C)=O)cc1.CCCCc1ncc(/C=C(\Cc2cccs2)C(=O)O)n1Cc1ccc(C(=O)C(C)(C)C)cc1.CCCc1nc2c(C)cc(-c3nc4ccccc4n3C)cc2n1Cc1ccc(-c2ccccc2C(=O)C(C)(C)C)cc1.CCOc1nc2cccc(C(=O)C(C)(C)C)c2n1Cc1ccc(-c2ccccc2-c2cn[nH]n2)cc1.

What is the InChIKey of (E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one?

The InChIKey is QFMZDIVMKDPSBQ-PJZBTKAJSA-N. The full InChI is InChI=1S/C37H38N4O.C29H29N5O2.C29H40N4O2.C28H31ClN4O.C28H34N2O2S.C27H32N2O3S/c1-7-12-33-39-34-24(2)21-27(36-38-30-15-10-11-16-31(30)40(36)6)22-32(34)41(33)23-25-17-19-26(20-18-25)28-13-8-9-14-29(28)35(42)37(3,4)5;1-5-36-28-31-24-12-8-11-23(27(35)29(2,3)4)26(24)34(28)18-19-13-15-20(16-14-19)21-9-6-7-10-22(21)25-17-30-33-32-25;1-7-8-13-26(34)33(27(20(2)3)28(35)29(4,5)6)19-21-14-16-22(17-15-21)23-11-9-10-12-24(23)25-18-30-32-31-25;1-5-6-11-23-32-26(29)24(25(34)28(2,3)4)33(23)18-19-12-14-20(15-13-19)21-9-7-8-10-22(21)27-30-16-17-31-27;1-6-7-10-26-29-18-24(30(26)19-21-11-13-22(14-12-21)20(2)31)16-23(27(32)28(3,4)5)17-25-9-8-15-33-25;1-5-6-9-24-28-17-22(15-21(26(31)32)16-23-8-7-14-33-23)29(24)18-19-10-12-20(13-11-19)25(30)27(2,3)4/h8-11,13-22H,7,12,23H2,1-6H3;6-17H,5,18H2,1-4H3,(H,30,32,33);9-12,14-17,20,27,30,32H,7-8,13,18-19H2,1-6H3;7-10,12-16H,5-6,11,17-18H2,1-4H3;8-9,11-16,18H,6-7,10,17,19H2,1-5H3;7-8,10-15,17H,5-6,9,16,18H2,1-4H3,(H,31,32)/b;;;;23-16+;21-15+/t;;27-;;;/m..0.../s1.

What are the key properties of (E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one?

(E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one has a molecular weight of 2913.31 g/mol, XLogP of 39.99, 52 rotatable bonds, 4 hydrogen bond donors, and 31 hydrogen bond acceptors.

Where does this data come from?

All data for (E)-1-[3-[(4-acetylphenyl)methyl]-2-butylimidazol-4-yl]-4,4-dimethyl-2-(thiophen-2-ylmethyl)pent-1-en-3-one;1-[2-butyl-5-chloro-3-[[4-[2-(4H-imidazol-2-yl)phenyl]phenyl]methyl]imidazol-4-yl]-2,2-dimethylpropan-1-one;(E)-3-[2-butyl-3-[[4-(2,2-dimethylpropanoyl)phenyl]methyl]imidazol-4-yl]-2-(thiophen-2-ylmethyl)prop-2-enoic acid;N-[[4-[2-(2,5-dihydro-1H-triazol-4-yl)phenyl]phenyl]methyl]-N-[(3S)-2,5,5-trimethyl-4-oxohexan-3-yl]pentanamide;2,2-dimethyl-1-[2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl]phenyl]phenyl]propan-1-one;1-[2-ethoxy-3-[[4-[2-(2H-triazol-4-yl)phenyl]phenyl]methyl]benzimidazol-4-yl]-2,2-dimethylpropan-1-one is sourced from PubChem (CID 165054726), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).