9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene

C135H108N12O6+6 — CID 162117265

About 9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene

9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene (PubChem CID 162117265) has the molecular formula C135H108N12O6+6 and a molecular weight of 1994.43 g/mol. Its IUPAC name is 9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene.

Molecular Properties

• Compound Name: 9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene
• PubChem CID: 162117265
• Molecular Formula: C135H108N12O6+6
• Molecular Weight: 1994.43 g/mol
• Exact Mass: 1992.85
• IUPAC Name: 9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene
• SMILES: CCc1cc[n+](C)c(-c2c(C)c3ccccc3c3c2oc2ncccc23)c1.Cc1c(-c2cccc[n+]2C)c2oc3cccnc3c2c2ccccc12.Cc1c(-c2cccc[n+]2C)c2oc3ccncc3c2c2ccccc12.Cc1c(-c2cccc[n+]2C)c2oc3cnccc3c2c2ccccc12.Cc1c(-c2cccc[n+]2C)c2oc3ncccc3c2c2ccccc12.Cc1cc[n+](C)c(-c2c(C)c3ccccc3c3c2oc2ncccc23)c1
• InChI: InChI=1S/C24H21N2O.C23H19N2O.4C22H17N2O/c1-4-16-11-13-26(3)20(14-16)21-15(2)17-8-5-6-9-18(17)22-19-10-7-12-25-24(19)27-23(21)22;1-14-10-12-25(3)19(13-14)20-15(2)16-7-4-5-8-17(16)21-18-9-6-11-24-23(18)26-22(20)21;1-14-15-8-3-4-9-16(15)20-17-10-7-12-23-22(17)25-21(20)19(14)18-11-5-6-13-24(18)2;1-14-15-8-3-4-9-16(15)20-21-18(11-7-12-23-21)25-22(20)19(14)17-10-5-6-13-24(17)2;1-14-15-7-3-4-8-16(15)21-17-13-23-11-10-19(17)25-22(21)20(14)18-9-5-6-12-24(18)2;1-14-15-7-3-4-8-16(15)21-17-10-11-23-13-19(17)25-22(21)20(14)18-9-5-6-12-24(18)2/h5-14H,4H2,1-3H3;4-13H,1-3H3;4*3-13H,1-2H3/q6*+1
• InChIKey: HWPFTXRZGGDOQP-UHFFFAOYSA-N
• XLogP: 30.48
• TPSA: 179.46 Ų
• H-Bond Acceptors: 12
• Rotatable Bonds: 7
• Heavy Atoms: 153
• Complexity: —

Lipinski Rule of Five

3 violations

Rule	Value
MW ≤ 500	1994.43
LogP ≤ 5	30.48
H-Bond Donors ≤ 5	0
H-Bond Acceptors ≤ 10	12

Computed Properties (RDKit)

• Structural Alerts: {'alert_name': 'quaternary_nitrogen_1', 'substructure': 'N/A'}

Frequently Asked Questions

What is the IUPAC name of 9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene?

The IUPAC name of 9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene (CID 162117265) is 9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene.

What is the SMILES notation for 9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene?

The canonical SMILES for 9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene is CCc1cc[n+](C)c(-c2c(C)c3ccccc3c3c2oc2ncccc23)c1.Cc1c(-c2cccc[n+]2C)c2oc3cccnc3c2c2ccccc12.Cc1c(-c2cccc[n+]2C)c2oc3ccncc3c2c2ccccc12.Cc1c(-c2cccc[n+]2C)c2oc3cnccc3c2c2ccccc12.Cc1c(-c2cccc[n+]2C)c2oc3ncccc3c2c2ccccc12.Cc1cc[n+](C)c(-c2c(C)c3ccccc3c3c2oc2ncccc23)c1.

What is the InChIKey of 9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene?

The InChIKey is HWPFTXRZGGDOQP-UHFFFAOYSA-N. The full InChI is InChI=1S/C24H21N2O.C23H19N2O.4C22H17N2O/c1-4-16-11-13-26(3)20(14-16)21-15(2)17-8-5-6-9-18(17)22-19-10-7-12-25-24(19)27-23(21)22;1-14-10-12-25(3)19(13-14)20-15(2)16-7-4-5-8-17(16)21-18-9-6-11-24-23(18)26-22(20)21;1-14-15-8-3-4-9-16(15)20-17-10-7-12-23-22(17)25-21(20)19(14)18-11-5-6-13-24(18)2;1-14-15-8-3-4-9-16(15)20-21-18(11-7-12-23-21)25-22(20)19(14)17-10-5-6-13-24(17)2;1-14-15-7-3-4-8-16(15)21-17-13-23-11-10-19(17)25-22(21)20(14)18-9-5-6-12-24(18)2;1-14-15-7-3-4-8-16(15)21-17-10-11-23-13-19(17)25-22(21)20(14)18-9-5-6-12-24(18)2/h5-14H,4H2,1-3H3;4-13H,1-3H3;4*3-13H,1-2H3/q6*+1.

What are the key properties of 9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene?

9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene has a molecular weight of 1994.43 g/mol, XLogP of 30.48, 7 rotatable bonds, 0 hydrogen bond donors, and 12 hydrogen bond acceptors.

Where does this data come from?

All data for 9-(1,4-dimethylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;9-(4-ethyl-1-methylpyridin-1-ium-2-yl)-8-methyl-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-13-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-14-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-15-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene;8-methyl-9-(1-methylpyridin-1-ium-2-yl)-11-oxa-16-azatetracyclo[8.7.0.02,7.012,17]heptadeca-1(10),2,4,6,8,12(17),13,15-octaene is sourced from PubChem (CID 162117265), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).