2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate

C174H252N12O24 — CID 157101619

About 2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate

2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate (PubChem CID 157101619) has the molecular formula C174H252N12O24 and a molecular weight of 2895.99 g/mol. Its IUPAC name is 2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate.

Molecular Properties

• Compound Name: 2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate
• PubChem CID: 157101619
• Molecular Formula: C174H252N12O24
• Molecular Weight: 2895.99 g/mol
• Exact Mass: 2893.89
• IUPAC Name: 2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate
• SMILES: CC1(C)CC(C(=O)OCCc2ccc(-c3ccc(CCOC(=O)C4CC(C)(C)NC4(C)C)cc3)cc2)C(C)(C)N1.CC1(C)CC(C(=O)OCCc2ccc(CCOC(=O)C3CC(C)(C)NC3(C)C)cc2)C(C)(C)N1.CC1(C)CC(C(=O)OCc2ccc(-c3ccc(COC(=O)C4CC(C)(C)NC4(C)C)cc3)cc2)C(C)(C)N1.CC1(C)CC(C(=O)OCc2ccc(COC(=O)C3CC(C)(C)NC3(C)C)cc2)C(C)(C)N1.CC1(C)CC(C(=O)Oc2ccc(-c3ccc(OC(=O)C4CC(C)(C)NC4(C)C)cc3)cc2)C(C)(C)N1.CC1(C)CC(C(=O)Oc2ccc(OC(=O)C3CC(C)(C)NC3(C)C)cc2)C(C)(C)N1
• InChI: InChI=1S/C34H48N2O4.C32H44N2O4.C30H40N2O4.C28H44N2O4.C26H40N2O4.C24H36N2O4/c1-31(2)21-27(33(5,6)35-31)29(37)39-19-17-23-9-13-25(14-10-23)26-15-11-24(12-16-26)18-20-40-30(38)28-22-32(3,4)36-34(28,7)8;1-29(2)17-25(31(5,6)33-29)27(35)37-19-21-9-13-23(14-10-21)24-15-11-22(12-16-24)20-38-28(36)26-18-30(3,4)34-32(26,7)8;1-27(2)17-23(29(5,6)31-27)25(33)35-21-13-9-19(10-14-21)20-11-15-22(16-12-20)36-26(34)24-18-28(3,4)32-30(24,7)8;1-25(2)17-21(27(5,6)29-25)23(31)33-15-13-19-9-11-20(12-10-19)14-16-34-24(32)22-18-26(3,4)30-28(22,7)8;1-23(2)13-19(25(5,6)27-23)21(29)31-15-17-9-11-18(12-10-17)16-32-22(30)20-14-24(3,4)28-26(20,7)8;1-21(2)13-17(23(5,6)25-21)19(27)29-15-9-11-16(12-10-15)30-20(28)18-14-22(3,4)26-24(18,7)8/h9-16,27-28,35-36H,17-22H2,1-8H3;9-16,25-26,33-34H,17-20H2,1-8H3;9-16,23-24,31-32H,17-18H2,1-8H3;9-12,21-22,29-30H,13-18H2,1-8H3;9-12,19-20,27-28H,13-16H2,1-8H3;9-12,17-18,25-26H,13-14H2,1-8H3
• InChIKey: AFVDASXNIUTZHN-UHFFFAOYSA-N
• XLogP: 29.26
• TPSA: 459.96 Ų
• H-Bond Donors: 12
• H-Bond Acceptors: 36
• Rotatable Bonds: 39
• Heavy Atoms: 210
• Complexity: —

Lipinski Rule of Five

4 violations

Rule	Value
MW ≤ 500	2895.99
LogP ≤ 5	29.26
H-Bond Donors ≤ 5	12
H-Bond Acceptors ≤ 10	36

Computed Properties (RDKit)

• Structural Alerts: {'alert_name': '>_2_ester_groups', 'substructure': 'N/A'}, {'alert_name': 'phenol_ester', 'substructure': 'N/A'}

Frequently Asked Questions

What is the IUPAC name of 2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate?

The IUPAC name of 2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate (CID 157101619) is 2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate.

What is the SMILES notation for 2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate?

The canonical SMILES for 2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate is CC1(C)CC(C(=O)OCCc2ccc(-c3ccc(CCOC(=O)C4CC(C)(C)NC4(C)C)cc3)cc2)C(C)(C)N1.CC1(C)CC(C(=O)OCCc2ccc(CCOC(=O)C3CC(C)(C)NC3(C)C)cc2)C(C)(C)N1.CC1(C)CC(C(=O)OCc2ccc(-c3ccc(COC(=O)C4CC(C)(C)NC4(C)C)cc3)cc2)C(C)(C)N1.CC1(C)CC(C(=O)OCc2ccc(COC(=O)C3CC(C)(C)NC3(C)C)cc2)C(C)(C)N1.CC1(C)CC(C(=O)Oc2ccc(-c3ccc(OC(=O)C4CC(C)(C)NC4(C)C)cc3)cc2)C(C)(C)N1.CC1(C)CC(C(=O)Oc2ccc(OC(=O)C3CC(C)(C)NC3(C)C)cc2)C(C)(C)N1.

What is the InChIKey of 2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate?

The InChIKey is AFVDASXNIUTZHN-UHFFFAOYSA-N. The full InChI is InChI=1S/C34H48N2O4.C32H44N2O4.C30H40N2O4.C28H44N2O4.C26H40N2O4.C24H36N2O4/c1-31(2)21-27(33(5,6)35-31)29(37)39-19-17-23-9-13-25(14-10-23)26-15-11-24(12-16-26)18-20-40-30(38)28-22-32(3,4)36-34(28,7)8;1-29(2)17-25(31(5,6)33-29)27(35)37-19-21-9-13-23(14-10-21)24-15-11-22(12-16-24)20-38-28(36)26-18-30(3,4)34-32(26,7)8;1-27(2)17-23(29(5,6)31-27)25(33)35-21-13-9-19(10-14-21)20-11-15-22(16-12-20)36-26(34)24-18-28(3,4)32-30(24,7)8;1-25(2)17-21(27(5,6)29-25)23(31)33-15-13-19-9-11-20(12-10-19)14-16-34-24(32)22-18-26(3,4)30-28(22,7)8;1-23(2)13-19(25(5,6)27-23)21(29)31-15-17-9-11-18(12-10-17)16-32-22(30)20-14-24(3,4)28-26(20,7)8;1-21(2)13-17(23(5,6)25-21)19(27)29-15-9-11-16(12-10-15)30-20(28)18-14-22(3,4)26-24(18,7)8/h9-16,27-28,35-36H,17-22H2,1-8H3;9-16,25-26,33-34H,17-20H2,1-8H3;9-16,23-24,31-32H,17-18H2,1-8H3;9-12,21-22,29-30H,13-18H2,1-8H3;9-12,19-20,27-28H,13-16H2,1-8H3;9-12,17-18,25-26H,13-14H2,1-8H3.

What are the key properties of 2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate?

2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate has a molecular weight of 2895.99 g/mol, XLogP of 29.26, 39 rotatable bonds, 12 hydrogen bond donors, and 36 hydrogen bond acceptors.

Where does this data come from?

All data for 2-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;2-[4-[4-[2-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyethyl]phenyl]phenyl]ethyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-[(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxymethyl]phenyl]phenyl]methyl 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl]phenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate;[4-(2,2,5,5-tetramethylpyrrolidine-3-carbonyl)oxyphenyl] 2,2,5,5-tetramethylpyrrolidine-3-carboxylate is sourced from PubChem (CID 157101619), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).