5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid

C93H130N14O30S — CID 161117555

IUPAC5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid
SMILESCCCNC(=O)[C@@H](CC(=O)[C@H](CO)NC(=O)[C@H](CC(=O)O)CC(=O)[C@H](CCC(=O)O)NC(=O)[C@@H](CC(=O)[C@@H](NC(=O)[C@@H]1CC(N=[N+]=[N-])CN1C(=O)[C@H](CC(=O)O)NC(=O)[C@@H](CC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(=O)O)CC(=O)[C@@H](N)Cc1ccccc1)Cc1ccc(O)cc1)[C@@H](C)O)[C@H](C)CC)Cc1ccc(O)cc1.CCOCCC(=O)CCCNC(=O)CCCC[C@@H]1SC[C@@H]2NC(=O)N[C@@H]21
InChIInChI=1S/C75H99N11O26.C18H31N3O4S/c1-5-24-78-69(106)44(25-42-12-16-49(89)17-13-42)29-61(94)56(38-87)82-72(109)47(33-66(102)103)31-60(93)54(21-23-64(98)99)80-73(110)51(39(3)6-2)35-62(95)68(40(4)88)83-74(111)57-34-48(84-85-77)37-86(57)75(112)55(36-67(104)105)81-70(107)45(26-43-14-18-50(90)19-15-43)30-59(92)53(20-22-63(96)97)79-71(108)46(32-65(100)101)28-58(91)52(76)27-41-10-8-7-9-11-41;1-2-25-11-9-13(22)6-5-10-19-16(23)8-4-3-7-15-17-14(12-26-15)20-18(24)21-17/h7-19,39-40,44-48,51-57,68,87-90H,5-6,20-38,76H2,1-4H3,(H,78,106)(H,79,108)(H,80,110)(H,81,107)(H,82,109)(H,83,111)(H,96,97)(H,98,99)(H,100,101)(H,102,103)(H,104,105);14-15,17H,2-12H2,1H3,(H,19,23)(H2,20,21,24)/t39-,40-,44-,45-,46+,47+,48?,51+,52+,53+,54+,55+,56+,57+,68+;14-,15-,17-/m10/s1
InChIKeyUKNBEYKBYVXSGY-ZCAQRNJBSA-N
MW1956.20 g/mol
LogP2.74
Rot. Bonds65

About 5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid

5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid (PubChem CID 161117555) has the molecular formula C93H130N14O30S and a molecular weight of 1956.20 g/mol. Its IUPAC name is 5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid.

Molecular Properties

Compound Name5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid
PubChem CID161117555
Molecular FormulaC93H130N14O30S
Molecular Weight1956.20 g/mol
Exact Mass1954.88
IUPAC Name5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid
SMILESCCCNC(=O)[C@@H](CC(=O)[C@H](CO)NC(=O)[C@H](CC(=O)O)CC(=O)[C@H](CCC(=O)O)NC(=O)[C@@H](CC(=O)[C@@H](NC(=O)[C@@H]1CC(N=[N+]=[N-])CN1C(=O)[C@H](CC(=O)O)NC(=O)[C@@H](CC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(=O)O)CC(=O)[C@@H](N)Cc1ccccc1)Cc1ccc(O)cc1)[C@@H](C)O)[C@H](C)CC)Cc1ccc(O)cc1.CCOCCC(=O)CCCNC(=O)CCCC[C@@H]1SC[C@@H]2NC(=O)N[C@@H]21
InChIInChI=1S/C75H99N11O26.C18H31N3O4S/c1-5-24-78-69(106)44(25-42-12-16-49(89)17-13-42)29-61(94)56(38-87)82-72(109)47(33-66(102)103)31-60(93)54(21-23-64(98)99)80-73(110)51(39(3)6-2)35-62(95)68(40(4)88)83-74(111)57-34-48(84-85-77)37-86(57)75(112)55(36-67(104)105)81-70(107)45(26-43-14-18-50(90)19-15-43)30-59(92)53(20-22-63(96)97)79-71(108)46(32-65(100)101)28-58(91)52(76)27-41-10-8-7-9-11-41;1-2-25-11-9-13(22)6-5-10-19-16(23)8-4-3-7-15-17-14(12-26-15)20-18(24)21-17/h7-19,39-40,44-48,51-57,68,87-90H,5-6,20-38,76H2,1-4H3,(H,78,106)(H,79,108)(H,80,110)(H,81,107)(H,82,109)(H,83,111)(H,96,97)(H,98,99)(H,100,101)(H,102,103)(H,104,105);14-15,17H,2-12H2,1H3,(H,19,23)(H2,20,21,24)/t39-,40-,44-,45-,46+,47+,48?,51+,52+,53+,54+,55+,56+,57+,68+;14-,15-,17-/m10/s1
InChIKeyUKNBEYKBYVXSGY-ZCAQRNJBSA-N
XLogP2.74
TPSA718.99 Ų
H-Bond Donors19
H-Bond Acceptors28
Rotatable Bonds65
Heavy Atoms138
Complexity

Lipinski Rule of Five

3 violations

RuleValue
MW ≤ 5001956.20
LogP ≤ 52.74
H-Bond Donors ≤ 519
H-Bond Acceptors ≤ 1028

Computed Properties (RDKit)

Structural Alerts{'alert_name': 'azo_A(324)', 'substructure': 'N/A'}, {'alert_name': 'Aliphatic_long_chain', 'substructure': 'N/A'}, {'alert_name': 'Azido_group', 'substructure': 'N/A'}, {'alert_name': 'biotin_analogue', 'substructure': 'N/A'}, {'alert_name': 'diazo_group', 'substructure': 'N/A'}

Analyze 5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid with MolForge

Explore ADMET properties, 3D molecular structure, drug-likeness score, and discover similar compounds using our AI-powered platform.

Launch Full Analysis

Related Compounds

Frequently Asked Questions

What is the IUPAC name of 5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid?
The IUPAC name of 5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid (CID 161117555) is 5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid.
What is the SMILES notation for 5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid?
The canonical SMILES for 5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid is CCCNC(=O)[C@@H](CC(=O)[C@H](CO)NC(=O)[C@H](CC(=O)O)CC(=O)[C@H](CCC(=O)O)NC(=O)[C@@H](CC(=O)[C@@H](NC(=O)[C@@H]1CC(N=[N+]=[N-])CN1C(=O)[C@H](CC(=O)O)NC(=O)[C@@H](CC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(=O)O)CC(=O)[C@@H](N)Cc1ccccc1)Cc1ccc(O)cc1)[C@@H](C)O)[C@H](C)CC)Cc1ccc(O)cc1.CCOCCC(=O)CCCNC(=O)CCCC[C@@H]1SC[C@@H]2NC(=O)N[C@@H]21.
What is the InChIKey of 5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid?
The InChIKey is UKNBEYKBYVXSGY-ZCAQRNJBSA-N. The full InChI is InChI=1S/C75H99N11O26.C18H31N3O4S/c1-5-24-78-69(106)44(25-42-12-16-49(89)17-13-42)29-61(94)56(38-87)82-72(109)47(33-66(102)103)31-60(93)54(21-23-64(98)99)80-73(110)51(39(3)6-2)35-62(95)68(40(4)88)83-74(111)57-34-48(84-85-77)37-86(57)75(112)55(36-67(104)105)81-70(107)45(26-43-14-18-50(90)19-15-43)30-59(92)53(20-22-63(96)97)79-71(108)46(32-65(100)101)28-58(91)52(76)27-41-10-8-7-9-11-41;1-2-25-11-9-13(22)6-5-10-19-16(23)8-4-3-7-15-17-14(12-26-15)20-18(24)21-17/h7-19,39-40,44-48,51-57,68,87-90H,5-6,20-38,76H2,1-4H3,(H,78,106)(H,79,108)(H,80,110)(H,81,107)(H,82,109)(H,83,111)(H,96,97)(H,98,99)(H,100,101)(H,102,103)(H,104,105);14-15,17H,2-12H2,1H3,(H,19,23)(H2,20,21,24)/t39-,40-,44-,45-,46+,47+,48?,51+,52+,53+,54+,55+,56+,57+,68+;14-,15-,17-/m10/s1.
What are the key properties of 5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid?
5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid has a molecular weight of 1956.20 g/mol, XLogP of 2.74, 65 rotatable bonds, 19 hydrogen bond donors, and 28 hydrogen bond acceptors.
Where does this data come from?
All data for 5-[(3aS,4S,6aR)-2-oxo-1,3,3a,4,6,6a-hexahydrothieno[3,4-d]imidazol-4-yl]-N-(6-ethoxy-4-oxohexyl)pentanamide;(3S,6S)-6-[[(2S,5S,6R)-5-[[(2S)-1-[(2S)-2-[[(2R,5S)-5-[[(2S,5S)-5-amino-2-(carboxymethyl)-4-oxo-6-phenylhexanoyl]amino]-7-carboxy-2-[(4-hydroxyphenyl)methyl]-4-oxoheptanoyl]amino]-3-carboxypropanoyl]-4-azidopyrrolidine-2-carbonyl]amino]-2-[(2R)-butan-2-yl]-6-hydroxy-4-oxoheptanoyl]amino]-3-[[(2S,5R)-1-hydroxy-5-[(4-hydroxyphenyl)methyl]-3,6-dioxo-6-(propylamino)hexan-2-yl]carbamoyl]-5-oxononanedioic acid is sourced from PubChem (CID 161117555), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).