About [(2R,5S)-9-amino-5-[[(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-6-(4-hydroxyphenyl)-2-methyl-4-oxohexanoyl]amino]-4-oxononan-2-yl]boronic acid;(2R)-2-(4-aminobutyl)-N-[(2R,5S)-9-amino-2-methyl-1-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-1,4-dioxononan-5-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R)-2-(4-aminobutyl)-N-[(4S,7R)-1-amino-7-methyl-8-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-5,8-dioxooctan-4-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-N-[(5S,8R)-1-amino-6-oxo-8-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]nonan-5-yl]-2-methyl-4-oxooctanediamide
[(2R,5S)-9-amino-5-[[(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-6-(4-hydroxyphenyl)-2-methyl-4-oxohexanoyl]amino]-4-oxononan-2-yl]boronic acid;(2R)-2-(4-aminobutyl)-N-[(2R,5S)-9-amino-2-methyl-1-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-1,4-dioxononan-5-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R)-2-(4-aminobutyl)-N-[(4S,7R)-1-amino-7-methyl-8-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-5,8-dioxooctan-4-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-N-[(5S,8R)-1-amino-6-oxo-8-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]nonan-5-yl]-2-methyl-4-oxooctanediamide (PubChem CID 159979465) has the molecular formula C219H327B4N17O34
and a molecular weight of 3785.36 g/mol. Its IUPAC name is [(2R,5S)-9-amino-5-[[(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-6-(4-hydroxyphenyl)-2-methyl-4-oxohexanoyl]amino]-4-oxononan-2-yl]boronic acid;(2R)-2-(4-aminobutyl)-N-[(2R,5S)-9-amino-2-methyl-1-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-1,4-dioxononan-5-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R)-2-(4-aminobutyl)-N-[(4S,7R)-1-amino-7-methyl-8-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-5,8-dioxooctan-4-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-N-[(5S,8R)-1-amino-6-oxo-8-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]nonan-5-yl]-2-methyl-4-oxooctanediamide.
Frequently Asked Questions
What is the IUPAC name of [(2R,5S)-9-amino-5-[[(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-6-(4-hydroxyphenyl)-2-methyl-4-oxohexanoyl]amino]-4-oxononan-2-yl]boronic acid;(2R)-2-(4-aminobutyl)-N-[(2R,5S)-9-amino-2-methyl-1-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-1,4-dioxononan-5-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R)-2-(4-aminobutyl)-N-[(4S,7R)-1-amino-7-methyl-8-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-5,8-dioxooctan-4-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-N-[(5S,8R)-1-amino-6-oxo-8-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]nonan-5-yl]-2-methyl-4-oxooctanediamide?
The IUPAC name of [(2R,5S)-9-amino-5-[[(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-6-(4-hydroxyphenyl)-2-methyl-4-oxohexanoyl]amino]-4-oxononan-2-yl]boronic acid;(2R)-2-(4-aminobutyl)-N-[(2R,5S)-9-amino-2-methyl-1-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-1,4-dioxononan-5-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R)-2-(4-aminobutyl)-N-[(4S,7R)-1-amino-7-methyl-8-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-5,8-dioxooctan-4-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-N-[(5S,8R)-1-amino-6-oxo-8-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]nonan-5-yl]-2-methyl-4-oxooctanediamide (CID 159979465) is [(2R,5S)-9-amino-5-[[(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-6-(4-hydroxyphenyl)-2-methyl-4-oxohexanoyl]amino]-4-oxononan-2-yl]boronic acid;(2R)-2-(4-aminobutyl)-N-[(2R,5S)-9-amino-2-methyl-1-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-1,4-dioxononan-5-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R)-2-(4-aminobutyl)-N-[(4S,7R)-1-amino-7-methyl-8-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-5,8-dioxooctan-4-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-N-[(5S,8R)-1-amino-6-oxo-8-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]nonan-5-yl]-2-methyl-4-oxooctanediamide.
What is the SMILES notation for [(2R,5S)-9-amino-5-[[(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-6-(4-hydroxyphenyl)-2-methyl-4-oxohexanoyl]amino]-4-oxononan-2-yl]boronic acid;(2R)-2-(4-aminobutyl)-N-[(2R,5S)-9-amino-2-methyl-1-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-1,4-dioxononan-5-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R)-2-(4-aminobutyl)-N-[(4S,7R)-1-amino-7-methyl-8-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-5,8-dioxooctan-4-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-N-[(5S,8R)-1-amino-6-oxo-8-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]nonan-5-yl]-2-methyl-4-oxooctanediamide?
The canonical SMILES for [(2R,5S)-9-amino-5-[[(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-6-(4-hydroxyphenyl)-2-methyl-4-oxohexanoyl]amino]-4-oxononan-2-yl]boronic acid;(2R)-2-(4-aminobutyl)-N-[(2R,5S)-9-amino-2-methyl-1-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-1,4-dioxononan-5-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R)-2-(4-aminobutyl)-N-[(4S,7R)-1-amino-7-methyl-8-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-5,8-dioxooctan-4-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-N-[(5S,8R)-1-amino-6-oxo-8-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]nonan-5-yl]-2-methyl-4-oxooctanediamide is CCCCc1ccc(-c2ccc(C(=O)CCCC(=O)C[C@@H](CCCCN)C(=O)N[C@@H](CCC(N)=O)C(=O)C[C@@H](C)C(=O)N[C@@H](CCCCN)C(=O)C[C@@H](C)B3OC4C[C@@H]5C[C@@H](C5(C)C)[C@]4(C)O3)cc2)cc1.CCCCc1ccc(-c2ccc(C(=O)CCCC(=O)C[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)C[C@@H](C)C(=O)N[C@@H](CC(C)C)C(=O)C[C@@H](C)B3OC4C[C@@H]5C[C@@H](C5(C)C)[C@]4(C)O3)cc2)cc1.CCCCc1ccc(-c2ccc(C(=O)CCCC(=O)C[C@@H](CCCCN)C(=O)N[C@@H](CCCN)C(=O)C[C@@H](C)C(=O)N[C@@H](CC(C)C)C(=O)C[C@@H](C)B3OC4C[C@@H]5C[C@@H](C5(C)C)[C@]4(C)O3)cc2)cc1.CCCCc1ccc(-c2ccc(C(=O)CCCC(=O)C[C@@H](CCCCN)C(=O)N[C@@H](Cc3ccc(O)cc3)C(=O)C[C@@H](C)C(=O)N[C@@H](CCCCN)C(=O)C[C@@H](C)B(O)O)cc2)cc1.
What is the InChIKey of [(2R,5S)-9-amino-5-[[(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-6-(4-hydroxyphenyl)-2-methyl-4-oxohexanoyl]amino]-4-oxononan-2-yl]boronic acid;(2R)-2-(4-aminobutyl)-N-[(2R,5S)-9-amino-2-methyl-1-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-1,4-dioxononan-5-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R)-2-(4-aminobutyl)-N-[(4S,7R)-1-amino-7-methyl-8-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-5,8-dioxooctan-4-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-N-[(5S,8R)-1-amino-6-oxo-8-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]nonan-5-yl]-2-methyl-4-oxooctanediamide?
The InChIKey is OFOMGDKOVBSTBJ-AYBLXSBGSA-N. The full InChI is InChI=1S/C57H87BN4O8.C56H84BN5O9.C56H85BN4O8.C50H71BN4O9/c1-9-10-16-40-21-23-41(24-22-40)42-25-27-43(28-26-42)49(64)20-15-18-46(63)34-44(17-11-13-29-59)55(68)61-47(19-12-14-30-60)50(65)32-38(4)54(67)62-48(31-37(2)3)51(66)33-39(5)58-69-53-36-45-35-52(56(45,6)7)57(53,8)70-58;1-7-8-14-38-19-21-39(22-20-38)40-23-25-41(26-24-40)47(64)18-13-16-44(63)33-42(15-9-11-29-58)54(69)62-46(27-28-52(60)67)48(65)31-36(2)53(68)61-45(17-10-12-30-59)49(66)32-37(3)57-70-51-35-43-34-50(55(43,4)5)56(51,6)71-57;1-9-10-15-39-20-22-40(23-21-39)41-24-26-42(27-25-41)48(63)19-13-17-45(62)33-43(16-11-12-28-58)54(67)60-46(18-14-29-59)49(64)31-37(4)53(66)61-47(30-36(2)3)50(65)32-38(5)57-68-52-35-44-34-51(55(44,6)7)56(52,8)69-57;1-4-5-11-36-16-20-38(21-17-36)39-22-24-40(25-23-39)46(58)15-10-13-43(57)33-41(12-6-8-28-52)50(62)55-45(32-37-18-26-42(56)27-19-37)47(59)30-34(2)49(61)54-44(14-7-9-29-53)48(60)31-35(3)51(63)64/h21-28,37-39,44-45,47-48,52-53H,9-20,29-36,59-60H2,1-8H3,(H,61,68)(H,62,67);19-26,36-37,42-43,45-46,50-51H,7-18,27-35,58-59H2,1-6H3,(H2,60,67)(H,61,68)(H,62,69);20-27,36-38,43-44,46-47,51-52H,9-19,28-35,58-59H2,1-8H3,(H,60,67)(H,61,66);16-27,34-35,41,44-45,56,63-64H,4-15,28-33,52-53H2,1-3H3,(H,54,61)(H,55,62)/t38-,39-,44-,45+,47+,48+,52+,53?,57+;36-,37-,42-,43+,45+,46+,50+,51?,56+;37-,38-,43-,44+,46+,47+,51+,52?,56+;34-,35-,41-,44+,45+/m1111/s1.
What are the key properties of [(2R,5S)-9-amino-5-[[(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-6-(4-hydroxyphenyl)-2-methyl-4-oxohexanoyl]amino]-4-oxononan-2-yl]boronic acid;(2R)-2-(4-aminobutyl)-N-[(2R,5S)-9-amino-2-methyl-1-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-1,4-dioxononan-5-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R)-2-(4-aminobutyl)-N-[(4S,7R)-1-amino-7-methyl-8-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-5,8-dioxooctan-4-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-N-[(5S,8R)-1-amino-6-oxo-8-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]nonan-5-yl]-2-methyl-4-oxooctanediamide?
[(2R,5S)-9-amino-5-[[(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-6-(4-hydroxyphenyl)-2-methyl-4-oxohexanoyl]amino]-4-oxononan-2-yl]boronic acid;(2R)-2-(4-aminobutyl)-N-[(2R,5S)-9-amino-2-methyl-1-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-1,4-dioxononan-5-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R)-2-(4-aminobutyl)-N-[(4S,7R)-1-amino-7-methyl-8-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-5,8-dioxooctan-4-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-N-[(5S,8R)-1-amino-6-oxo-8-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]nonan-5-yl]-2-methyl-4-oxooctanediamide has a molecular weight of 3785.36 g/mol, XLogP of 32.76, 128 rotatable bonds, 20 hydrogen bond donors, and 42 hydrogen bond acceptors.
Where does this data come from?
All data for [(2R,5S)-9-amino-5-[[(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-6-(4-hydroxyphenyl)-2-methyl-4-oxohexanoyl]amino]-4-oxononan-2-yl]boronic acid;(2R)-2-(4-aminobutyl)-N-[(2R,5S)-9-amino-2-methyl-1-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-1,4-dioxononan-5-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R)-2-(4-aminobutyl)-N-[(4S,7R)-1-amino-7-methyl-8-[[(4S,7R)-2-methyl-5-oxo-7-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]octan-4-yl]amino]-5,8-dioxooctan-4-yl]-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanamide;(2R,5S)-5-[[(2R)-2-(4-aminobutyl)-8-[4-(4-butylphenyl)phenyl]-4,8-dioxooctanoyl]amino]-N-[(5S,8R)-1-amino-6-oxo-8-[(1S,2S,8S)-2,9,9-trimethyl-3,5-dioxa-4-boratricyclo[6.1.1.02,6]decan-4-yl]nonan-5-yl]-2-methyl-4-oxooctanediamide is sourced from PubChem (CID 159979465), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).