(2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid

C116H153N27O45S4 — CID 149427094

About (2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid

(2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid (PubChem CID 149427094) has the molecular formula C116H153N27O45S4 and a molecular weight of 2773.91 g/mol. Its IUPAC name is (2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid.

Molecular Properties

• Compound Name: (2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid
• PubChem CID: 149427094
• Molecular Formula: C116H153N27O45S4
• Molecular Weight: 2773.91 g/mol
• Exact Mass: 2771.94
• IUPAC Name: (2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid
• SMILES: Nc1nc(N)c2nc(CCc3ccc(C(=O)C[C@@H](CCC(=O)OCCSSC[C@H](CC(=O)[C@H](CCC(=O)NC[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO)NC(=O)[C@H](CCC(=O)O)CC(=O)[C@H](CSSCCOC(=O)CC[C@H](NC(=O)c4ccc(NCc5cnc6nc(N)nc(N)c6n5)cc4)C(=O)O)NC(=O)[C@H](CCC(=O)NC[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO)CC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)NC[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO)CC(=O)CC[C@H](NC(=O)c4ccc(NCc5cnc6nc(N)[nH]c(=O)c6n5)cc4)C(=O)O)C(=O)O)C(=O)O)cc3)cnc2n1
• InChI: InChI=1S/C116H153N27O45S4/c117-99-90-101(140-114(119)138-99)127-40-64(130-90)14-3-53-1-4-54(5-2-53)73(148)38-60(110(179)180)13-29-88(165)187-31-33-189-191-51-61(111(181)182)39-75(150)68(21-26-85(160)126-47-79(154)95(169)98(172)82(157)50-146)133-107(176)59(12-27-86(161)162)37-76(151)72(52-192-190-34-32-188-89(166)30-23-71(113(185)186)136-105(174)56-8-15-62(16-9-56)122-41-65-43-128-102-91(131-65)100(118)139-115(120)141-102)137-108(177)58(11-25-84(159)125-46-78(153)94(168)97(171)81(156)49-145)36-74(149)69(22-28-87(163)164)134-106(175)57(10-24-83(158)124-45-77(152)93(167)96(170)80(155)48-144)35-67(147)19-20-70(112(183)184)135-104(173)55-6-17-63(18-7-55)123-42-66-44-129-103-92(132-66)109(178)143-116(121)142-103/h1-2,4-9,15-18,40,43-44,57-61,68-72,77-82,93-98,122-123,144-146,152-157,167-172H,3,10-14,19-39,41-42,45-52H2,(H,124,158)(H,125,159)(H,126,160)(H,133,176)(H,134,175)(H,135,173)(H,136,174)(H,137,177)(H,161,162)(H,163,164)(H,179,180)(H,181,182)(H,183,184)(H,185,186)(H4,117,119,127,138,140)(H4,118,120,128,139,141)(H3,121,129,142,143,178)/t57-,58-,59-,60-,61+,68+,69+,70+,71+,72+,77+,78+,79+,80-,81-,82-,93-,94-,95-,96-,97-,98-/m1/s1
• InChIKey: YUHWUGAJOHELKY-MAXWAOEBSA-N
• XLogP: -7.10
• TPSA: 1226.81 Ų
• H-Bond Donors: 37
• H-Bond Acceptors: 61
• Rotatable Bonds: 91
• Heavy Atoms: 192
• Complexity: —

Lipinski Rule of Five

3 violations

Rule	Value
MW ≤ 500	2773.91
LogP ≤ 5	-7.10
H-Bond Donors ≤ 5	37
H-Bond Acceptors ≤ 10	61

Computed Properties (RDKit)

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

Frequently Asked Questions

What is the IUPAC name of (2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid?

The IUPAC name of (2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid (CID 149427094) is (2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid.

What is the SMILES notation for (2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid?

The canonical SMILES for (2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid is Nc1nc(N)c2nc(CCc3ccc(C(=O)C[C@@H](CCC(=O)OCCSSC[C@H](CC(=O)[C@H](CCC(=O)NC[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO)NC(=O)[C@H](CCC(=O)O)CC(=O)[C@H](CSSCCOC(=O)CC[C@H](NC(=O)c4ccc(NCc5cnc6nc(N)nc(N)c6n5)cc4)C(=O)O)NC(=O)[C@H](CCC(=O)NC[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO)CC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)NC[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO)CC(=O)CC[C@H](NC(=O)c4ccc(NCc5cnc6nc(N)[nH]c(=O)c6n5)cc4)C(=O)O)C(=O)O)C(=O)O)cc3)cnc2n1.

What is the InChIKey of (2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid?

The InChIKey is YUHWUGAJOHELKY-MAXWAOEBSA-N. The full InChI is InChI=1S/C116H153N27O45S4/c117-99-90-101(140-114(119)138-99)127-40-64(130-90)14-3-53-1-4-54(5-2-53)73(148)38-60(110(179)180)13-29-88(165)187-31-33-189-191-51-61(111(181)182)39-75(150)68(21-26-85(160)126-47-79(154)95(169)98(172)82(157)50-146)133-107(176)59(12-27-86(161)162)37-76(151)72(52-192-190-34-32-188-89(166)30-23-71(113(185)186)136-105(174)56-8-15-62(16-9-56)122-41-65-43-128-102-91(131-65)100(118)139-115(120)141-102)137-108(177)58(11-25-84(159)125-46-78(153)94(168)97(171)81(156)49-145)36-74(149)69(22-28-87(163)164)134-106(175)57(10-24-83(158)124-45-77(152)93(167)96(170)80(155)48-144)35-67(147)19-20-70(112(183)184)135-104(173)55-6-17-63(18-7-55)123-42-66-44-129-103-92(132-66)109(178)143-116(121)142-103/h1-2,4-9,15-18,40,43-44,57-61,68-72,77-82,93-98,122-123,144-146,152-157,167-172H,3,10-14,19-39,41-42,45-52H2,(H,124,158)(H,125,159)(H,126,160)(H,133,176)(H,134,175)(H,135,173)(H,136,174)(H,137,177)(H,161,162)(H,163,164)(H,179,180)(H,181,182)(H,183,184)(H,185,186)(H4,117,119,127,138,140)(H4,118,120,128,139,141)(H3,121,129,142,143,178)/t57-,58-,59-,60-,61+,68+,69+,70+,71+,72+,77+,78+,79+,80-,81-,82-,93-,94-,95-,96-,97-,98-/m1/s1.

What are the key properties of (2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid?

(2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid has a molecular weight of 2773.91 g/mol, XLogP of -7.10, 91 rotatable bonds, 37 hydrogen bond donors, and 61 hydrogen bond acceptors.

Where does this data come from?

All data for (2S,7R)-2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]amino]-7-[[(3S,6R)-1-carboxy-6-[[(2R,5R)-7-carboxy-5-[[(4S,7R)-7-carboxy-8-[2-[(4R)-4-carboxy-6-[4-[2-(2,4-diaminopteridin-6-yl)ethyl]phenyl]-6-oxohexanoyl]oxyethyldisulfanyl]-1,5-dioxo-1-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]octan-4-yl]carbamoyl]-1-[2-[(4S)-4-carboxy-4-[[4-[(2,4-diaminopteridin-6-yl)methylamino]benzoyl]amino]butanoyl]oxyethyldisulfanyl]-3-oxoheptan-2-yl]carbamoyl]-4,9-dioxo-9-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]nonan-3-yl]carbamoyl]-5,10-dioxo-10-[[(2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl]amino]decanoic acid is sourced from PubChem (CID 149427094), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).