bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione

C152H270N12O73 — CID 158835676

About bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione

bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione (PubChem CID 158835676) has the molecular formula C152H270N12O73 and a molecular weight of 3433.84 g/mol. Its IUPAC name is bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione.

Molecular Properties

• Compound Name: bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione
• PubChem CID: 158835676
• Molecular Formula: C152H270N12O73
• Molecular Weight: 3433.84 g/mol
• Exact Mass: 3431.78
• IUPAC Name: bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione
• SMILES: CC(=O)[C@H](CCCCN)NC(=O)CCCCCCC(=O)CCCCC[C@@H](C(=O)NCCO[C@@H]1O[C@@H](C)[C@@H](O)[C@@H](O)[C@@H]1O)N(CC(=O)NCCO[C@@H]1O[C@@H](C)[C@@H](O)[C@@H](O)[C@@H]1O)CC(=O)NCCO[C@@H]1O[C@@H](C)[C@@H](O)[C@@H](O)[C@@H]1O.CC(=O)[C@H](CCCCN)NC(=O)CCCCCCC(=O)CCCCC[C@@H](C(=O)NCCO[C@@H]1O[C@@H](C)[C@@H](O)[C@@H](O)[C@@H]1O)N(CC(=O)NCCO[C@@H]1O[C@@H](C)[C@@H](O)[C@@H](O)[C@@H]1O)CC(=O)NCCO[C@@H]1O[C@@H](C)[C@@H](O)[C@@H](O)[C@@H]1O.CCC(=O)CCCCC(=O)CCCO[C@H]1O[C@H](CO[C@H]2O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]2O)[C@@H](O)[C@H](O)[C@@H]1O.CCC(=O)CCCCC(=O)CCCO[C@H]1O[C@H](CO[C@H]2O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]2O)[C@@H](O)[C@H](O[C@H]2O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]2O)[C@@H]1O
• InChI: InChI=1S/2C50H90N6O21.C29H50O18.C23H40O13/c2*1-28(57)33(16-12-13-19-51)55-35(59)18-11-6-5-8-14-32(58)15-9-7-10-17-34(47(71)54-22-25-74-50-46(70)43(67)40(64)31(4)77-50)56(26-36(60)52-20-23-72-48-44(68)41(65)38(62)29(2)75-48)27-37(61)53-21-24-73-49-45(69)42(66)39(63)30(3)76-49;1-2-13(32)6-3-4-7-14(33)8-5-9-42-28-25(41)26(47-29-24(40)22(38)19(35)16(11-31)45-29)20(36)17(46-28)12-43-27-23(39)21(37)18(34)15(10-30)44-27;1-2-12(25)6-3-4-7-13(26)8-5-9-33-22-20(31)19(30)17(28)15(36-22)11-34-23-21(32)18(29)16(27)14(10-24)35-23/h2*29-31,33-34,38-46,48-50,62-70H,5-27,51H2,1-4H3,(H,52,60)(H,53,61)(H,54,71)(H,55,59);15-31,34-41H,2-12H2,1H3;14-24,27-32H,2-11H2,1H3/t2*29-,30-,31-,33-,34-,38+,39+,40+,41+,42+,43+,44-,45-,46-,48+,49+,50+;15-,16-,17-,18-,19-,20-,21+,22+,23+,24+,25+,26+,27+,28+,29-;14-,15-,16-,17-,18+,19+,20+,21+,22+,23+/m0011/s1
• InChIKey: IXPHBQJADVFVIP-NATAXQJZSA-N
• XLogP: -15.94
• TPSA: 1338.99 Ų
• H-Bond Donors: 45
• H-Bond Acceptors: 77
• Rotatable Bonds: 107
• Heavy Atoms: 237
• Complexity: —

Lipinski Rule of Five

3 violations

Rule	Value
MW ≤ 500	3433.84
LogP ≤ 5	-15.94
H-Bond Donors ≤ 5	45
H-Bond Acceptors ≤ 10	77

Frequently Asked Questions

What is the IUPAC name of bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione?

The IUPAC name of bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione (CID 158835676) is bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione.

What is the SMILES notation for bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione?

The canonical SMILES for bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione is CC(=O)[C@H](CCCCN)NC(=O)CCCCCCC(=O)CCCCC[C@@H](C(=O)NCCO[C@@H]1O[C@@H](C)[C@@H](O)[C@@H](O)[C@@H]1O)N(CC(=O)NCCO[C@@H]1O[C@@H](C)[C@@H](O)[C@@H](O)[C@@H]1O)CC(=O)NCCO[C@@H]1O[C@@H](C)[C@@H](O)[C@@H](O)[C@@H]1O.CC(=O)[C@H](CCCCN)NC(=O)CCCCCCC(=O)CCCCC[C@@H](C(=O)NCCO[C@@H]1O[C@@H](C)[C@@H](O)[C@@H](O)[C@@H]1O)N(CC(=O)NCCO[C@@H]1O[C@@H](C)[C@@H](O)[C@@H](O)[C@@H]1O)CC(=O)NCCO[C@@H]1O[C@@H](C)[C@@H](O)[C@@H](O)[C@@H]1O.CCC(=O)CCCCC(=O)CCCO[C@H]1O[C@H](CO[C@H]2O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]2O)[C@@H](O)[C@H](O)[C@@H]1O.CCC(=O)CCCCC(=O)CCCO[C@H]1O[C@H](CO[C@H]2O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]2O)[C@@H](O)[C@H](O[C@H]2O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]2O)[C@@H]1O.

What is the InChIKey of bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione?

The InChIKey is IXPHBQJADVFVIP-NATAXQJZSA-N. The full InChI is InChI=1S/2C50H90N6O21.C29H50O18.C23H40O13/c2*1-28(57)33(16-12-13-19-51)55-35(59)18-11-6-5-8-14-32(58)15-9-7-10-17-34(47(71)54-22-25-74-50-46(70)43(67)40(64)31(4)77-50)56(26-36(60)52-20-23-72-48-44(68)41(65)38(62)29(2)75-48)27-37(61)53-21-24-73-49-45(69)42(66)39(63)30(3)76-49;1-2-13(32)6-3-4-7-14(33)8-5-9-42-28-25(41)26(47-29-24(40)22(38)19(35)16(11-31)45-29)20(36)17(46-28)12-43-27-23(39)21(37)18(34)15(10-30)44-27;1-2-12(25)6-3-4-7-13(26)8-5-9-33-22-20(31)19(30)17(28)15(36-22)11-34-23-21(32)18(29)16(27)14(10-24)35-23/h2*29-31,33-34,38-46,48-50,62-70H,5-27,51H2,1-4H3,(H,52,60)(H,53,61)(H,54,71)(H,55,59);15-31,34-41H,2-12H2,1H3;14-24,27-32H,2-11H2,1H3/t2*29-,30-,31-,33-,34-,38+,39+,40+,41+,42+,43+,44-,45-,46-,48+,49+,50+;15-,16-,17-,18-,19-,20-,21+,22+,23+,24+,25+,26+,27+,28+,29-;14-,15-,16-,17-,18+,19+,20+,21+,22+,23+/m0011/s1.

What are the key properties of bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione?

bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione has a molecular weight of 3433.84 g/mol, XLogP of -15.94, 107 rotatable bonds, 45 hydrogen bond donors, and 77 hydrogen bond acceptors.

Where does this data come from?

All data for bis((2S)-N'-[(3S)-7-amino-2-oxoheptan-3-yl]-2-[bis[2-oxo-2-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethylamino]ethyl]amino]-8-oxo-N-[2-[(2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyethyl]pentadecanediamide);11-[(2S,3S,4S,5R,6R)-3,5-dihydroxy-4-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione;11-[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-[[(2S,3S,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxymethyl]oxan-2-yl]oxyundecane-3,8-dione is sourced from PubChem (CID 158835676), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).