2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one

C73H84Br5F5N26O24P2 — CID 162129729

About 2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one

2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one (PubChem CID 162129729) has the molecular formula C73H84Br5F5N26O24P2 and a molecular weight of 2266.09 g/mol. Its IUPAC name is 2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one.

Molecular Properties

• Compound Name: 2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one
• PubChem CID: 162129729
• Molecular Formula: C73H84Br5F5N26O24P2
• Molecular Weight: 2266.09 g/mol
• Exact Mass: 2260.15
• IUPAC Name: 2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one
• SMILES: CC(=O)[C@H](C)CP(=O)(OC[C@H]1O[C@@H](c2cnc3c(=O)[nH]c(N)nn23)C(F)(Br)[C@H]1O)Oc1ccccc1.CC(=O)[C@H](C)CP(=O)(OC[C@H]1O[C@@H](c2cnc3c(N)nc(N)nn23)C(F)(Br)[C@H]1O)Oc1ccccc1.Nc1nc(N)c2ncc([C@@H]3O[C@H](CO)[C@H](O)C3(F)Br)n2n1.Nc1nn2c([C@@H]3O[C@H](CO)[C@H](O)C3(F)Br)ccc2c(=O)[nH]1.Nc1nn2c([C@@H]3O[C@H](CO)[C@H](O)C3(F)Br)cnc2c(=O)[nH]1
• InChI: InChI=1S/C21H25BrFN6O6P.C21H24BrFN5O7P.C11H12BrFN4O4.C10H12BrFN6O3.C10H11BrFN5O4/c1-11(12(2)30)10-36(32,35-13-6-4-3-5-7-13)33-9-15-16(31)21(22,23)17(34-15)14-8-26-19-18(24)27-20(25)28-29(14)19;1-11(12(2)29)10-36(32,35-13-6-4-3-5-7-13)33-9-15-16(30)21(22,23)17(34-15)14-8-25-18-19(31)26-20(24)27-28(14)18;12-11(13)7(19)6(3-18)21-8(11)4-1-2-5-9(20)15-10(14)16-17(4)5;11-10(12)5(20)4(2-19)21-6(10)3-1-15-8-7(13)16-9(14)17-18(3)8;11-10(12)5(19)4(2-18)21-6(10)3-1-14-7-8(20)15-9(13)16-17(3)7/h3-8,11,15-17,31H,9-10H2,1-2H3,(H4,24,25,27,28);3-8,11,15-17,30H,9-10H2,1-2H3,(H3,24,26,27,31);1-2,6-8,18-19H,3H2,(H3,14,15,16,20);1,4-6,19-20H,2H2,(H4,13,14,16,17);1,4-6,18-19H,2H2,(H3,13,15,16,20)/t2*11-,15-,16+,17+,21?,36?;6-,7+,8+,11?;2*4-,5+,6+,10?/m11111/s1
• InChIKey: ZIMVSSSCZISAOX-KHTYMQJUSA-N
• XLogP: 2.49
• TPSA: 757.75 Ų
• H-Bond Donors: 18
• H-Bond Acceptors: 47
• Rotatable Bonds: 24
• Heavy Atoms: 135
• Complexity: —

Lipinski Rule of Five

3 violations

Rule	Value
MW ≤ 500	2266.09
LogP ≤ 5	2.49
H-Bond Donors ≤ 5	18
H-Bond Acceptors ≤ 10	47

Computed Properties (RDKit)

• Structural Alerts: {'alert_name': 'het_6_tetrazine(18)', 'substructure': 'N/A'}, {'alert_name': 'alkyl_halide', 'substructure': 'N/A'}, {'alert_name': 'phosphor', 'substructure': 'N/A'}

Frequently Asked Questions

What is the IUPAC name of 2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one?

The IUPAC name of 2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one (CID 162129729) is 2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one.

What is the SMILES notation for 2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one?

The canonical SMILES for 2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one is CC(=O)[C@H](C)CP(=O)(OC[C@H]1O[C@@H](c2cnc3c(=O)[nH]c(N)nn23)C(F)(Br)[C@H]1O)Oc1ccccc1.CC(=O)[C@H](C)CP(=O)(OC[C@H]1O[C@@H](c2cnc3c(N)nc(N)nn23)C(F)(Br)[C@H]1O)Oc1ccccc1.Nc1nc(N)c2ncc([C@@H]3O[C@H](CO)[C@H](O)C3(F)Br)n2n1.Nc1nn2c([C@@H]3O[C@H](CO)[C@H](O)C3(F)Br)ccc2c(=O)[nH]1.Nc1nn2c([C@@H]3O[C@H](CO)[C@H](O)C3(F)Br)cnc2c(=O)[nH]1.

What is the InChIKey of 2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one?

The InChIKey is ZIMVSSSCZISAOX-KHTYMQJUSA-N. The full InChI is InChI=1S/C21H25BrFN6O6P.C21H24BrFN5O7P.C11H12BrFN4O4.C10H12BrFN6O3.C10H11BrFN5O4/c1-11(12(2)30)10-36(32,35-13-6-4-3-5-7-13)33-9-15-16(31)21(22,23)17(34-15)14-8-26-19-18(24)27-20(25)28-29(14)19;1-11(12(2)29)10-36(32,35-13-6-4-3-5-7-13)33-9-15-16(30)21(22,23)17(34-15)14-8-25-18-19(31)26-20(24)27-28(14)18;12-11(13)7(19)6(3-18)21-8(11)4-1-2-5-9(20)15-10(14)16-17(4)5;11-10(12)5(20)4(2-19)21-6(10)3-1-15-8-7(13)16-9(14)17-18(3)8;11-10(12)5(19)4(2-18)21-6(10)3-1-14-7-8(20)15-9(13)16-17(3)7/h3-8,11,15-17,31H,9-10H2,1-2H3,(H4,24,25,27,28);3-8,11,15-17,30H,9-10H2,1-2H3,(H3,24,26,27,31);1-2,6-8,18-19H,3H2,(H3,14,15,16,20);1,4-6,19-20H,2H2,(H4,13,14,16,17);1,4-6,18-19H,2H2,(H3,13,15,16,20)/t2*11-,15-,16+,17+,21?,36?;6-,7+,8+,11?;2*4-,5+,6+,10?/m11111/s1.

What are the key properties of 2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one?

2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one has a molecular weight of 2266.09 g/mol, XLogP of 2.49, 24 rotatable bonds, 18 hydrogen bond donors, and 47 hydrogen bond acceptors.

Where does this data come from?

All data for 2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-(hydroxymethyl)oxolan-2-yl]-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one;2-amino-7-[(2S,4S,5R)-3-bromo-3-fluoro-4-hydroxy-5-[[[(2S)-2-methyl-3-oxobutyl]-phenoxyphosphoryl]oxymethyl]oxolan-2-yl]-3H-imidazo[2,1-f][1,2,4]triazin-4-one;(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-2-(hydroxymethyl)oxolan-3-ol;(3S)-4-[[(2R,3S,5S)-4-bromo-5-(2,4-diaminoimidazo[2,1-f][1,2,4]triazin-7-yl)-4-fluoro-3-hydroxyoxolan-2-yl]methoxy-phenoxyphosphoryl]-3-methylbutan-2-one is sourced from PubChem (CID 162129729), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).