(2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide

C129H123Br4Cl4F3N34O17 — CID 161168406

About (2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide

(2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide (PubChem CID 161168406) has the molecular formula C129H123Br4Cl4F3N34O17 and a molecular weight of 2940.05 g/mol. Its IUPAC name is (2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide.

Molecular Properties

• Compound Name: (2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide
• PubChem CID: 161168406
• Molecular Formula: C129H123Br4Cl4F3N34O17
• Molecular Weight: 2940.05 g/mol
• Exact Mass: 2932.52
• IUPAC Name: (2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide
• SMILES: CCC1=NC([N+](=O)[O-])=C(C[N+](C)(C)C/C=C/C(=O)Cc2cc3c(Nc4ccc(OCc5ccccn5)c(Cl)c4)ncnc3cn2)C1.C[N+](C)(C/C=C/C(=O)Cc1cc2c(Nc3ccc(OCc4ccccn4)c(Cl)c3)ncnc2cn1)CC1=C([N+](=O)[O-])N=C(C#N)C1.C[N+](C)(C/C=C/C(=O)Cc1cc2c(Nc3ccc(OCc4ccccn4)c(Cl)c3)ncnc2cn1)CC1=C([N+](=O)[O-])N=C(C(F)(F)F)C1.C[N+](C)(C/C=C/C(=O)Cc1cc2c(Nc3ccc(OCc4ccccn4)c(Cl)c3)ncnc2cn1)CC1=C([N+](=O)[O-])N=C(C(N)=O)C1.[Br-].[Br-].[Br-].[Br-]
• InChI: InChI=1S/C33H34ClN8O4.C32H29ClF3N8O4.C32H30ClN9O5.C32H29ClN9O4.4BrH/c1-4-23-14-22(33(40-23)41(44)45)19-42(2,3)13-7-9-27(43)15-26-16-28-30(18-36-26)37-21-38-32(28)39-24-10-11-31(29(34)17-24)46-20-25-8-5-6-12-35-25;1-44(2,17-20-12-29(32(34,35)36)42-31(20)43(46)47)11-5-7-24(45)13-23-14-25-27(16-38-23)39-19-40-30(25)41-21-8-9-28(26(33)15-21)48-18-22-6-3-4-10-37-22;1-42(2,17-20-12-27(30(34)44)40-32(20)41(45)46)11-5-7-24(43)13-23-14-25-28(16-36-23)37-19-38-31(25)39-21-8-9-29(26(33)15-21)47-18-22-6-3-4-10-35-22;1-42(2,18-21-12-25(16-34)40-32(21)41(44)45)11-5-7-26(43)13-24-14-27-29(17-36-24)37-20-38-31(27)39-22-8-9-30(28(33)15-22)46-19-23-6-3-4-10-35-23;;;;/h5-12,16-18,21H,4,13-15,19-20H2,1-3H3,(H,37,38,39);3-10,14-16,19H,11-13,17-18H2,1-2H3,(H,39,40,41);3-10,14-16,19H,11-13,17-18H2,1-2H3,(H2-,34,37,38,39,44);3-10,14-15,17,20H,11-13,18-19H2,1-2H3,(H,37,38,39);4*1H/q2*+1;;+1;;;;/p-3/b9-7+;3*7-5+
• InChIKey: KJTXOKBPBIAGHA-MWMMTCGPSA-K
• XLogP: 8.89
• TPSA: 648.44 Ų
• H-Bond Donors: 5
• H-Bond Acceptors: 42
• Rotatable Bonds: 54
• Heavy Atoms: 191
• Complexity: —

Lipinski Rule of Five

3 violations

Rule	Value
MW ≤ 500	2940.05
LogP ≤ 5	8.89
H-Bond Donors ≤ 5	5
H-Bond Acceptors ≤ 10	42

Computed Properties (RDKit)

• Structural Alerts: {'alert_name': 'Michael_acceptor_1', 'substructure': 'N/A'}, {'alert_name': 'nitro_group', 'substructure': 'N/A'}, {'alert_name': 'Oxygen-nitrogen_single_bond', 'substructure': 'N/A'}, {'alert_name': 'quaternary_nitrogen_2', 'substructure': 'N/A'}

Frequently Asked Questions

What is the IUPAC name of (2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide?

The IUPAC name of (2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide (CID 161168406) is (2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide.

What is the SMILES notation for (2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide?

The canonical SMILES for (2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide is CCC1=NC([N+](=O)[O-])=C(C[N+](C)(C)C/C=C/C(=O)Cc2cc3c(Nc4ccc(OCc5ccccn5)c(Cl)c4)ncnc3cn2)C1.C[N+](C)(C/C=C/C(=O)Cc1cc2c(Nc3ccc(OCc4ccccn4)c(Cl)c3)ncnc2cn1)CC1=C([N+](=O)[O-])N=C(C#N)C1.C[N+](C)(C/C=C/C(=O)Cc1cc2c(Nc3ccc(OCc4ccccn4)c(Cl)c3)ncnc2cn1)CC1=C([N+](=O)[O-])N=C(C(F)(F)F)C1.C[N+](C)(C/C=C/C(=O)Cc1cc2c(Nc3ccc(OCc4ccccn4)c(Cl)c3)ncnc2cn1)CC1=C([N+](=O)[O-])N=C(C(N)=O)C1.[Br-].[Br-].[Br-].[Br-].

What is the InChIKey of (2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide?

The InChIKey is KJTXOKBPBIAGHA-MWMMTCGPSA-K. The full InChI is InChI=1S/C33H34ClN8O4.C32H29ClF3N8O4.C32H30ClN9O5.C32H29ClN9O4.4BrH/c1-4-23-14-22(33(40-23)41(44)45)19-42(2,3)13-7-9-27(43)15-26-16-28-30(18-36-26)37-21-38-32(28)39-24-10-11-31(29(34)17-24)46-20-25-8-5-6-12-35-25;1-44(2,17-20-12-29(32(34,35)36)42-31(20)43(46)47)11-5-7-24(45)13-23-14-25-27(16-38-23)39-19-40-30(25)41-21-8-9-28(26(33)15-21)48-18-22-6-3-4-10-37-22;1-42(2,17-20-12-27(30(34)44)40-32(20)41(45)46)11-5-7-24(43)13-23-14-25-28(16-36-23)37-19-38-31(25)39-21-8-9-29(26(33)15-21)47-18-22-6-3-4-10-35-22;1-42(2,18-21-12-25(16-34)40-32(21)41(44)45)11-5-7-26(43)13-24-14-27-29(17-36-24)37-20-38-31(27)39-22-8-9-30(28(33)15-22)46-19-23-6-3-4-10-35-23;;;;/h5-12,16-18,21H,4,13-15,19-20H2,1-3H3,(H,37,38,39);3-10,14-16,19H,11-13,17-18H2,1-2H3,(H,39,40,41);3-10,14-16,19H,11-13,17-18H2,1-2H3,(H2-,34,37,38,39,44);3-10,14-15,17,20H,11-13,18-19H2,1-2H3,(H,37,38,39);4*1H/q2*+1;;+1;;;;/p-3/b9-7+;3*7-5+;;;;.

What are the key properties of (2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide?

(2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide has a molecular weight of 2940.05 g/mol, XLogP of 8.89, 54 rotatable bonds, 5 hydrogen bond donors, and 42 hydrogen bond acceptors.

Where does this data come from?

All data for (2-carbamoyl-5-nitro-3H-pyrrol-4-yl)methyl-[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-cyano-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-dimethyl-[[5-nitro-2-(trifluoromethyl)-3H-pyrrol-4-yl]methyl]azanium;[(E)-5-[4-[3-chloro-4-(pyridin-2-ylmethoxy)anilino]pyrido[3,4-d]pyrimidin-6-yl]-4-oxopent-2-enyl]-[(2-ethyl-5-nitro-3H-pyrrol-4-yl)methyl]-dimethylazanium;tetrabromide is sourced from PubChem (CID 161168406), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).