2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline

C190H108N8 — CID 159951853

About 2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline

2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline (PubChem CID 159951853) has the molecular formula C190H108N8 and a molecular weight of 2503.01 g/mol. Its IUPAC name is 2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline.

Molecular Properties

• Compound Name: 2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline
• PubChem CID: 159951853
• Molecular Formula: C190H108N8
• Molecular Weight: 2503.01 g/mol
• Exact Mass: 2500.87
• IUPAC Name: 2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline
• SMILES: c1ccc(-c2nc(-c3cc4c5c6c3Cc3ccc7c(c3-6)-c3c(ccc6c3-c3c(ccc(c3-5)C4)C6)C7)nc3ccccc23)cc1.c1ccc(-c2ncc(-c3cc4c5c6c3Cc3ccc7c(c3-6)-c3c(ccc6c3-c3c(ccc(c3-5)C4)C6)C7)cn2)cc1.c1ccc2cc(-c3cc4c5c6c3Cc3ccc7c(c3-6)-c3c(ccc6c3-c3c(ccc(c3-5)C4)C6)C7)ccc2c1.c1ccc2nc(-c3cc4c5c6c3Cc3ccc7c(c3-6)-c3c(ccc6c3-c3c(ccc(c3-5)C4)C6)C7)cnc2c1.c1ccc2nc(-c3cc4c5c6c3Cc3ccc7c(c3-6)-c3c(ccc6c3-c3c(ccc(c3-5)C4)C6)C7)ncc2c1
• InChI: InChI=1S/C42H24N2.C38H22N2.C38H22.2C36H20N2/c1-2-6-21(7-3-1)41-29-8-4-5-9-32(29)43-42(44-41)31-20-28-18-26-13-12-24-16-22-10-11-23-17-25-14-15-27-19-30(31)40-38(27)36(25)34(23)33(22)35(24)37(26)39(28)40;1-2-4-19(5-3-1)38-39-17-27(18-40-38)28-16-26-14-24-9-8-22-12-20-6-7-21-13-23-10-11-25-15-29(28)37-35(25)33(23)31(21)30(20)32(22)34(24)36(26)37;1-2-4-20-13-21(6-5-19(20)3-1)29-18-28-16-26-10-9-24-14-22-7-8-23-15-25-11-12-27-17-30(29)38-36(27)34(25)32(23)31(22)33(24)35(26)37(28)38;1-2-4-27-26(3-1)37-16-28(38-27)24-15-23-13-21-8-7-19-11-17-5-6-18-12-20-9-10-22-14-25(24)36-34(22)32(20)30(18)29(17)31(19)33(21)35(23)36;1-2-4-27-23(3-1)16-37-36(38-27)26-15-24-13-21-8-7-19-11-17-5-6-18-12-20-9-10-22-14-25(26)35-33(22)31(20)29(18)28(17)30(19)32(21)34(24)35/h1-15,20H,16-19H2;1-11,16-18H,12-15H2;1-13,18H,14-17H2;2*1-10,15-16H,11-14H2
• InChIKey: OCFHMDHQXXNLAQ-UHFFFAOYSA-N
• XLogP: 42.87
• TPSA: 103.12 Ų
• H-Bond Acceptors: 8
• Rotatable Bonds: 7
• Heavy Atoms: 198
• Complexity: —

Lipinski Rule of Five

2 violations

Rule	Value
MW ≤ 500	2503.01
LogP ≤ 5	42.87
H-Bond Donors ≤ 5	0
H-Bond Acceptors ≤ 10	8

Frequently Asked Questions

What is the IUPAC name of 2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline?

The IUPAC name of 2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline (CID 159951853) is 2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline.

What is the SMILES notation for 2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline?

The canonical SMILES for 2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline is c1ccc(-c2nc(-c3cc4c5c6c3Cc3ccc7c(c3-6)-c3c(ccc6c3-c3c(ccc(c3-5)C4)C6)C7)nc3ccccc23)cc1.c1ccc(-c2ncc(-c3cc4c5c6c3Cc3ccc7c(c3-6)-c3c(ccc6c3-c3c(ccc(c3-5)C4)C6)C7)cn2)cc1.c1ccc2cc(-c3cc4c5c6c3Cc3ccc7c(c3-6)-c3c(ccc6c3-c3c(ccc(c3-5)C4)C6)C7)ccc2c1.c1ccc2nc(-c3cc4c5c6c3Cc3ccc7c(c3-6)-c3c(ccc6c3-c3c(ccc(c3-5)C4)C6)C7)cnc2c1.c1ccc2nc(-c3cc4c5c6c3Cc3ccc7c(c3-6)-c3c(ccc6c3-c3c(ccc(c3-5)C4)C6)C7)ncc2c1.

What is the InChIKey of 2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline?

The InChIKey is OCFHMDHQXXNLAQ-UHFFFAOYSA-N. The full InChI is InChI=1S/C42H24N2.C38H22N2.C38H22.2C36H20N2/c1-2-6-21(7-3-1)41-29-8-4-5-9-32(29)43-42(44-41)31-20-28-18-26-13-12-24-16-22-10-11-23-17-25-14-15-27-19-30(31)40-38(27)36(25)34(23)33(22)35(24)37(26)39(28)40;1-2-4-19(5-3-1)38-39-17-27(18-40-38)28-16-26-14-24-9-8-22-12-20-6-7-21-13-23-10-11-25-15-29(28)37-35(25)33(23)31(21)30(20)32(22)34(24)36(26)37;1-2-4-20-13-21(6-5-19(20)3-1)29-18-28-16-26-10-9-24-14-22-7-8-23-15-25-11-12-27-17-30(29)38-36(27)34(25)32(23)31(22)33(24)35(26)37(28)38;1-2-4-27-26(3-1)37-16-28(38-27)24-15-23-13-21-8-7-19-11-17-5-6-18-12-20-9-10-22-14-25(24)36-34(22)32(20)30(18)29(17)31(19)33(21)35(23)36;1-2-4-27-23(3-1)16-37-36(38-27)26-15-24-13-21-8-7-19-11-17-5-6-18-12-20-9-10-22-14-25(26)35-33(22)31(20)29(18)28(17)30(19)32(21)34(24)35/h1-15,20H,16-19H2;1-11,16-18H,12-15H2;1-13,18H,14-17H2;2*1-10,15-16H,11-14H2.

What are the key properties of 2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline?

2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline has a molecular weight of 2503.01 g/mol, XLogP of 42.87, 7 rotatable bonds, 0 hydrogen bond donors, and 8 hydrogen bond acceptors.

Where does this data come from?

All data for 2-naphthalen-2-ylnonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaene;5-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-2-phenylpyrimidine;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)-4-phenylquinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinazoline;2-(2-nonacyclo[17.8.1.04,26.06,25.09,24.011,23.014,22.016,21.020,27]octacosa-1,3,6(25),7,9(24),11(23),12,14(22),16(21),17,19,26-dodecaenyl)quinoxaline is sourced from PubChem (CID 159951853), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).