(2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide

C140H187F12N21O19 — CID 161254585

About (2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide

(2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide (PubChem CID 161254585) has the molecular formula C140H187F12N21O19 and a molecular weight of 2696.14 g/mol. Its IUPAC name is (2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide.

Molecular Properties

• Compound Name: (2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide
• PubChem CID: 161254585
• Molecular Formula: C140H187F12N21O19
• Molecular Weight: 2696.14 g/mol
• Exact Mass: 2694.41
• IUPAC Name: (2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide
• SMILES: CCC(=O)N[C@@H](C(=O)N1CCN(C)CC1)[C@@H](C)c1ccc(NC(=O)[C@@H](CC(=O)C(F)(F)c2ccc(OC)nc2)C2CCC(F)(F)CC2)c(F)c1.CCC(=O)N[C@@H](C(=O)N1CCN(C)CC1)[C@@H](C)c1ccc(NC(=O)[C@@H](CC(=O)C(F)(F)c2ccc(OC)nc2)C2CCCCC2)c(F)c1.CCC(=O)N[C@@H](C(=O)N1CCN(C)CC1)[C@@H](C)c1ccc(NC(=O)[C@@H](CC(=O)C(F)(F)c2ccc(OC)nc2)C2CCCCCC2)c(F)c1.CCC(=O)N[C@@H](C(=O)N1CCN(C)CC1)[C@@H](C)c1ccc(NC(=O)[C@@H](CC(=O)c2ccnn2CC)C2CCCCCC2)c(F)c1
• InChI: InChI=1S/C36H48F3N5O5.C35H44F5N5O5.C35H46F3N5O5.C34H49FN6O4/c1-5-31(46)42-33(35(48)44-18-16-43(3)17-19-44)23(2)25-12-14-29(28(37)20-25)41-34(47)27(24-10-8-6-7-9-11-24)21-30(45)36(38,39)26-13-15-32(49-4)40-22-26;1-5-29(47)43-31(33(49)45-16-14-44(3)15-17-45)21(2)23-6-8-27(26(36)18-23)42-32(48)25(22-10-12-34(37,38)13-11-22)19-28(46)35(39,40)24-7-9-30(50-4)41-20-24;1-5-30(45)41-32(34(47)43-17-15-42(3)16-18-43)22(2)24-11-13-28(27(36)19-24)40-33(46)26(23-9-7-6-8-10-23)20-29(44)35(37,38)25-12-14-31(48-4)39-21-25;1-5-31(43)38-32(34(45)40-19-17-39(4)18-20-40)23(3)25-13-14-28(27(35)21-25)37-33(44)26(24-11-9-7-8-10-12-24)22-30(42)29-15-16-36-41(29)6-2/h12-15,20,22-24,27,33H,5-11,16-19,21H2,1-4H3,(H,41,47)(H,42,46);6-9,18,20-22,25,31H,5,10-17,19H2,1-4H3,(H,42,48)(H,43,47);11-14,19,21-23,26,32H,5-10,15-18,20H2,1-4H3,(H,40,46)(H,41,45);13-16,21,23-24,26,32H,5-12,17-20,22H2,1-4H3,(H,37,44)(H,38,43)/t23-,27-,33+;21-,25-,31+;22-,26-,32+;23-,26-,32+/m0000/s1
• InChIKey: VBSPGDALQGLRDR-MSFYPVLWSA-N
• XLogP: 19.91
• TPSA: 479.46 Ų
• H-Bond Donors: 8
• H-Bond Acceptors: 28
• Rotatable Bonds: 51
• Heavy Atoms: 192
• Complexity: —

Lipinski Rule of Five

4 violations

Rule	Value
MW ≤ 500	2696.14
LogP ≤ 5	19.91
H-Bond Donors ≤ 5	8
H-Bond Acceptors ≤ 10	28

Frequently Asked Questions

What is the IUPAC name of (2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide?

The IUPAC name of (2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide (CID 161254585) is (2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide.

What is the SMILES notation for (2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide?

The canonical SMILES for (2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide is CCC(=O)N[C@@H](C(=O)N1CCN(C)CC1)[C@@H](C)c1ccc(NC(=O)[C@@H](CC(=O)C(F)(F)c2ccc(OC)nc2)C2CCC(F)(F)CC2)c(F)c1.CCC(=O)N[C@@H](C(=O)N1CCN(C)CC1)[C@@H](C)c1ccc(NC(=O)[C@@H](CC(=O)C(F)(F)c2ccc(OC)nc2)C2CCCCC2)c(F)c1.CCC(=O)N[C@@H](C(=O)N1CCN(C)CC1)[C@@H](C)c1ccc(NC(=O)[C@@H](CC(=O)C(F)(F)c2ccc(OC)nc2)C2CCCCCC2)c(F)c1.CCC(=O)N[C@@H](C(=O)N1CCN(C)CC1)[C@@H](C)c1ccc(NC(=O)[C@@H](CC(=O)c2ccnn2CC)C2CCCCCC2)c(F)c1.

What is the InChIKey of (2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide?

The InChIKey is VBSPGDALQGLRDR-MSFYPVLWSA-N. The full InChI is InChI=1S/C36H48F3N5O5.C35H44F5N5O5.C35H46F3N5O5.C34H49FN6O4/c1-5-31(46)42-33(35(48)44-18-16-43(3)17-19-44)23(2)25-12-14-29(28(37)20-25)41-34(47)27(24-10-8-6-7-9-11-24)21-30(45)36(38,39)26-13-15-32(49-4)40-22-26;1-5-29(47)43-31(33(49)45-16-14-44(3)15-17-45)21(2)23-6-8-27(26(36)18-23)42-32(48)25(22-10-12-34(37,38)13-11-22)19-28(46)35(39,40)24-7-9-30(50-4)41-20-24;1-5-30(45)41-32(34(47)43-17-15-42(3)16-18-43)22(2)24-11-13-28(27(36)19-24)40-33(46)26(23-9-7-6-8-10-23)20-29(44)35(37,38)25-12-14-31(48-4)39-21-25;1-5-31(43)38-32(34(45)40-19-17-39(4)18-20-40)23(3)25-13-14-28(27(35)21-25)37-33(44)26(24-11-9-7-8-10-12-24)22-30(42)29-15-16-36-41(29)6-2/h12-15,20,22-24,27,33H,5-11,16-19,21H2,1-4H3,(H,41,47)(H,42,46);6-9,18,20-22,25,31H,5,10-17,19H2,1-4H3,(H,42,48)(H,43,47);11-14,19,21-23,26,32H,5-10,15-18,20H2,1-4H3,(H,40,46)(H,41,45);13-16,21,23-24,26,32H,5-12,17-20,22H2,1-4H3,(H,37,44)(H,38,43)/t23-,27-,33+;21-,25-,31+;22-,26-,32+;23-,26-,32+/m0000/s1.

What are the key properties of (2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide?

(2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide has a molecular weight of 2696.14 g/mol, XLogP of 19.91, 51 rotatable bonds, 8 hydrogen bond donors, and 28 hydrogen bond acceptors.

Where does this data come from?

All data for (2S)-2-cycloheptyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-cycloheptyl-4-(2-ethylpyrazol-3-yl)-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-4-oxobutanamide;(2S)-2-cyclohexyl-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide;(2S)-2-(4,4-difluorocyclohexyl)-5,5-difluoro-N-[2-fluoro-4-[(2S,3R)-4-(4-methylpiperazin-1-yl)-4-oxo-3-(propanoylamino)butan-2-yl]phenyl]-5-(6-methoxy-3-pyridinyl)-4-oxopentanamide is sourced from PubChem (CID 161254585), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).