(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid

C111H168N30O31 — CID 134148885

About (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid

(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid (PubChem CID 134148885) has the molecular formula C111H168N30O31 and a molecular weight of 2418.74 g/mol. Its IUPAC name is (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid.

Molecular Properties

• Compound Name: (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid
• PubChem CID: 134148885
• Molecular Formula: C111H168N30O31
• Molecular Weight: 2418.74 g/mol
• Exact Mass: 2417.25
• IUPAC Name: (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid
• SMILES: [H]/N=C(/N)NCCC[C@H](NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](Cc1ccc(O)cc1)NC(=O)CNC(=O)[C@H](CC(=O)O)NC(=O)[C@@H](NC(=O)[C@H](Cc1ccccc1)NC(=O)C(NC(=O)[C@H](CC(N)=O)NC(=O)CNC(=O)[C@H](CCCCN)NC(=O)[C@H](CO)NC(=O)[C@H](CCC(N)=O)NC(=O)[C@H](Cc1ccccc1)NC(C)=O)C(C)C)[C@@H](C)O)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCN/C(N)=N/[H])C(=O)N[C@@H](C)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(C)C)C(=O)O
• InChI: InChI=1S/C111H168N30O31/c1-58(2)47-75(100(162)131-71(33-23-45-120-110(116)117)95(157)124-61(7)92(154)128-70(32-20-22-44-113)97(159)138-82(109(171)172)48-59(3)4)134-96(158)72(34-24-46-121-111(118)119)130-98(160)74(40-42-88(150)151)133-103(165)78(50-65-27-15-11-16-28-65)135-102(164)77(52-67-35-37-68(145)38-36-67)126-86(148)56-123-94(156)81(54-89(152)153)137-108(170)91(62(8)143)141-104(166)79(51-66-29-17-12-18-30-66)136-107(169)90(60(5)6)140-105(167)80(53-85(115)147)127-87(149)55-122-93(155)69(31-19-21-43-112)129-106(168)83(57-142)139-99(161)73(39-41-84(114)146)132-101(163)76(125-63(9)144)49-64-25-13-10-14-26-64/h10-18,25-30,35-38,58-62,69-83,90-91,142-143,145H,19-24,31-34,39-57,112-113H2,1-9H3,(H2,114,146)(H2,115,147)(H,122,155)(H,123,156)(H,124,157)(H,125,144)(H,126,148)(H,127,149)(H,128,154)(H,129,168)(H,130,160)(H,131,162)(H,132,163)(H,133,165)(H,134,158)(H,135,164)(H,136,169)(H,137,170)(H,138,159)(H,139,161)(H,140,167)(H,141,166)(H,150,151)(H,152,153)(H,171,172)(H4,116,117,120)(H4,118,119,121)/t61-,62+,69-,70-,71-,72-,73-,74-,75-,76-,77-,78-,79-,80-,81-,82-,83-,90?,91-/m0/s1
• InChIKey: BERZDKDBSWZUPI-GEGLMNHGSA-N
• XLogP: -8.87
• TPSA: 1016.61 Ų
• H-Bond Donors: 36
• H-Bond Acceptors: 32
• Rotatable Bonds: 81
• Heavy Atoms: 172
• Complexity: —

Lipinski Rule of Five

3 violations

Rule	Value
MW ≤ 500	2418.74
LogP ≤ 5	-8.87
H-Bond Donors ≤ 5	36
H-Bond Acceptors ≤ 10	32

Computed Properties (RDKit)

• Structural Alerts: {'alert_name': 'Aliphatic_long_chain', 'substructure': 'N/A'}, {'alert_name': 'imine_1', 'substructure': 'N/A'}, {'alert_name': 'imine_2', 'substructure': 'N/A'}

Frequently Asked Questions

What is the IUPAC name of (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid?

The IUPAC name of (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid (CID 134148885) is (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid.

What is the SMILES notation for (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid?

The canonical SMILES for (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid is [H]/N=C(/N)NCCC[C@H](NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](Cc1ccc(O)cc1)NC(=O)CNC(=O)[C@H](CC(=O)O)NC(=O)[C@@H](NC(=O)[C@H](Cc1ccccc1)NC(=O)C(NC(=O)[C@H](CC(N)=O)NC(=O)CNC(=O)[C@H](CCCCN)NC(=O)[C@H](CO)NC(=O)[C@H](CCC(N)=O)NC(=O)[C@H](Cc1ccccc1)NC(C)=O)C(C)C)[C@@H](C)O)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCN/C(N)=N/[H])C(=O)N[C@@H](C)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(C)C)C(=O)O.

What is the InChIKey of (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid?

The InChIKey is BERZDKDBSWZUPI-GEGLMNHGSA-N. The full InChI is InChI=1S/C111H168N30O31/c1-58(2)47-75(100(162)131-71(33-23-45-120-110(116)117)95(157)124-61(7)92(154)128-70(32-20-22-44-113)97(159)138-82(109(171)172)48-59(3)4)134-96(158)72(34-24-46-121-111(118)119)130-98(160)74(40-42-88(150)151)133-103(165)78(50-65-27-15-11-16-28-65)135-102(164)77(52-67-35-37-68(145)38-36-67)126-86(148)56-123-94(156)81(54-89(152)153)137-108(170)91(62(8)143)141-104(166)79(51-66-29-17-12-18-30-66)136-107(169)90(60(5)6)140-105(167)80(53-85(115)147)127-87(149)55-122-93(155)69(31-19-21-43-112)129-106(168)83(57-142)139-99(161)73(39-41-84(114)146)132-101(163)76(125-63(9)144)49-64-25-13-10-14-26-64/h10-18,25-30,35-38,58-62,69-83,90-91,142-143,145H,19-24,31-34,39-57,112-113H2,1-9H3,(H2,114,146)(H2,115,147)(H,122,155)(H,123,156)(H,124,157)(H,125,144)(H,126,148)(H,127,149)(H,128,154)(H,129,168)(H,130,160)(H,131,162)(H,132,163)(H,133,165)(H,134,158)(H,135,164)(H,136,169)(H,137,170)(H,138,159)(H,139,161)(H,140,167)(H,141,166)(H,150,151)(H,152,153)(H,171,172)(H4,116,117,120)(H4,118,119,121)/t61-,62+,69-,70-,71-,72-,73-,74-,75-,76-,77-,78-,79-,80-,81-,82-,83-,90?,91-/m0/s1.

What are the key properties of (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid?

(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid has a molecular weight of 2418.74 g/mol, XLogP of -8.87, 81 rotatable bonds, 36 hydrogen bond donors, and 32 hydrogen bond acceptors.

Where does this data come from?

All data for (2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-phenylpropanoyl]amino]-5-amino-5-oxopentanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]acetyl]amino]-4-amino-4-oxobutanoyl]amino]-3-methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]acetyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-phenylpropanoyl]amino]-4-carboxybutanoyl]amino]-5-carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5-carbamimidamidopentanoyl]amino]propanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoic acid is sourced from PubChem (CID 134148885), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).