5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid

C127H146N17O48P3S2 — CID 59081266

About 5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid

5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid (PubChem CID 59081266) has the molecular formula C127H146N17O48P3S2 and a molecular weight of 2835.69 g/mol. Its IUPAC name is 5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid.

Molecular Properties

• Compound Name: 5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid
• PubChem CID: 59081266
• Molecular Formula: C127H146N17O48P3S2
• Molecular Weight: 2835.69 g/mol
• Exact Mass: 2833.82
• IUPAC Name: 5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid
• SMILES: [C-]#[N+]C1C2N3C(c4c(cc(C)c(OC)c4C(=O)N(CCOCC(=O)NCCOCCOCCN(CCOCCOCCOCCNC(=O)CCC(NC(=O)c4ccc(N(Cc5cnc6nc(N)nc(O)c6n5)C(=O)OCc5ccc(OP6(=O)OCCCO6)c(C(=O)OCOC(=O)CCC(=O)O)c5)cc4)C(=O)O)C(=O)COCCOCP(=O)(O)COCCOCC(=O)O)c4ccccc4SSCC(NC(=O)OCC4c5ccccc5-c5ccccc54)C(=O)NCCOP(=O)(O)O)C23C)C2Cc3c(OC(C)=O)c(C)c4c(c3C(CN3C(=O)c5ccccc5C3=O)N21)OCO4
• InChI: InChI=1S/C127H146N17O48P3S2/c1-74-58-90-105(108-94-60-88-104(112-111(185-71-186-112)75(2)110(88)191-76(3)145)95(143(94)115(129-5)113-127(90,4)144(108)113)63-142-119(157)85-20-11-12-21-86(85)120(142)158)106(109(74)171-6)121(159)140(93-22-13-14-23-97(93)197-196-69-92(117(155)132-36-44-188-194(167,168)169)136-125(163)182-65-89-83-18-9-7-16-81(83)82-17-8-10-19-84(82)89)39-47-177-66-99(147)131-35-43-173-48-50-174-45-37-139(100(148)67-178-54-56-180-72-193(165,166)73-181-57-55-179-68-102(151)152)38-46-175-51-53-176-52-49-172-42-34-130-98(146)31-29-91(122(160)161)135-116(154)78-25-27-80(28-26-78)141(62-79-61-133-114-107(134-79)118(156)138-124(128)137-114)126(164)183-64-77-24-30-96(192-195(170)189-40-15-41-190-195)87(59-77)123(162)187-70-184-103(153)33-32-101(149)150/h7-14,16-28,30,58-59,61,89,91-92,94-95,108,113,115H,15,29,31-57,60,62-73H2,1-4,6H3,(H,130,146)(H,131,147)(H,132,155)(H,135,154)(H,136,163)(H,149,150)(H,151,152)(H,160,161)(H,165,166)(H2,167,168,169)(H3,128,133,137,138,156)
• InChIKey: RKJZABIIBCSSOU-UHFFFAOYSA-N
• XLogP: 8.93
• TPSA: 830.30 Ų
• H-Bond Donors: 13
• H-Bond Acceptors: 51
• Rotatable Bonds: 77
• Heavy Atoms: 197
• Complexity: —

Lipinski Rule of Five

4 violations

Rule	Value
MW ≤ 500	2835.69
LogP ≤ 5	8.93
H-Bond Donors ≤ 5	13
H-Bond Acceptors ≤ 10	51

Computed Properties (RDKit)

• Structural Alerts: {'alert_name': 'dyes5A(27)', 'substructure': 'N/A'}, {'alert_name': '>_2_ester_groups', 'substructure': 'N/A'}, {'alert_name': 'Aliphatic_long_chain', 'substructure': 'N/A'}, {'alert_name': 'Carbo_cation/anion', 'substructure': 'N/A'}, {'alert_name': 'disulphide', 'substructure': 'N/A'}

Frequently Asked Questions

What is the IUPAC name of 5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid?

The IUPAC name of 5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid (CID 59081266) is 5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid.

What is the SMILES notation for 5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid?

The canonical SMILES for 5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid is [C-]#[N+]C1C2N3C(c4c(cc(C)c(OC)c4C(=O)N(CCOCC(=O)NCCOCCOCCN(CCOCCOCCOCCNC(=O)CCC(NC(=O)c4ccc(N(Cc5cnc6nc(N)nc(O)c6n5)C(=O)OCc5ccc(OP6(=O)OCCCO6)c(C(=O)OCOC(=O)CCC(=O)O)c5)cc4)C(=O)O)C(=O)COCCOCP(=O)(O)COCCOCC(=O)O)c4ccccc4SSCC(NC(=O)OCC4c5ccccc5-c5ccccc54)C(=O)NCCOP(=O)(O)O)C23C)C2Cc3c(OC(C)=O)c(C)c4c(c3C(CN3C(=O)c5ccccc5C3=O)N21)OCO4.

What is the InChIKey of 5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid?

The InChIKey is RKJZABIIBCSSOU-UHFFFAOYSA-N. The full InChI is InChI=1S/C127H146N17O48P3S2/c1-74-58-90-105(108-94-60-88-104(112-111(185-71-186-112)75(2)110(88)191-76(3)145)95(143(94)115(129-5)113-127(90,4)144(108)113)63-142-119(157)85-20-11-12-21-86(85)120(142)158)106(109(74)171-6)121(159)140(93-22-13-14-23-97(93)197-196-69-92(117(155)132-36-44-188-194(167,168)169)136-125(163)182-65-89-83-18-9-7-16-81(83)82-17-8-10-19-84(82)89)39-47-177-66-99(147)131-35-43-173-48-50-174-45-37-139(100(148)67-178-54-56-180-72-193(165,166)73-181-57-55-179-68-102(151)152)38-46-175-51-53-176-52-49-172-42-34-130-98(146)31-29-91(122(160)161)135-116(154)78-25-27-80(28-26-78)141(62-79-61-133-114-107(134-79)118(156)138-124(128)137-114)126(164)183-64-77-24-30-96(192-195(170)189-40-15-41-190-195)87(59-77)123(162)187-70-184-103(153)33-32-101(149)150/h7-14,16-28,30,58-59,61,89,91-92,94-95,108,113,115H,15,29,31-57,60,62-73H2,1-4,6H3,(H,130,146)(H,131,147)(H,132,155)(H,135,154)(H,136,163)(H,149,150)(H,151,152)(H,160,161)(H,165,166)(H2,167,168,169)(H3,128,133,137,138,156).

What are the key properties of 5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid?

5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid has a molecular weight of 2835.69 g/mol, XLogP of 8.93, 77 rotatable bonds, 13 hydrogen bond donors, and 51 hydrogen bond acceptors.

Where does this data come from?

All data for 5-[2-[2-[2-[2-[2-[2-[2-[[2-[2-[N-[22-acetyloxy-14-[(1,3-dioxoisoindol-2-yl)methyl]-12-isocyano-5-methoxy-6,9,21-trimethyl-17,19-dioxa-10,13-diazaheptacyclo[11.11.0.02,10.03,8.09,11.015,23.016,20]tetracosa-3(8),4,6,15,20,22-hexaene-4-carbonyl]-2-[[2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-oxo-3-(2-phosphonooxyethylamino)propyl]disulfanyl]anilino]ethoxy]acetyl]amino]ethoxy]ethoxy]ethyl-[2-[2-[[2-(carboxymethoxy)ethoxymethyl-hydroxyphosphoryl]methoxy]ethoxy]acetyl]amino]ethoxy]ethoxy]ethoxy]ethylamino]-2-[[4-[(2-amino-4-hydroxypteridin-6-yl)methyl-[[3-(3-carboxypropanoyloxymethoxycarbonyl)-4-[(2-oxo-1,3,2λ5-dioxaphosphinan-2-yl)oxy]phenyl]methoxycarbonyl]amino]benzoyl]amino]-5-oxopentanoic acid is sourced from PubChem (CID 59081266), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).