About (2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethylpyrrolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](1,2,3-13C3)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate
(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethylpyrrolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](1,2,3-13C3)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate (PubChem CID 158481678) has the molecular formula C144H224N32O48
and a molecular weight of 3235.08 g/mol. Its IUPAC name is (2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethylpyrrolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](1,2,3-13C3)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate.
Frequently Asked Questions
What is the IUPAC name of (2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethylpyrrolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](1,2,3-13C3)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate?
The IUPAC name of (2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethylpyrrolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](1,2,3-13C3)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate (CID 158481678) is (2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethylpyrrolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](1,2,3-13C3)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate.
What is the SMILES notation for (2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethylpyrrolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](1,2,3-13C3)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate?
The canonical SMILES for (2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethylpyrrolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](1,2,3-13C3)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate is CCC1CCCN1CC(=O)[15NH][13CH2][13CH2][13C](=O)[15NH][13CH2][13CH2][13C](=O)ON1C(=O)CCC1=O.CCC1CCCN1[13CH2][13C](=O)[15NH]CC[13C](=O)[15NH][13CH2][13CH2][13C](=O)ON1C(=O)CCC1=O.CCC1CCC[15N]1C[13C](=O)[15NH]CC[13C](=O)[15NH][13CH2][13CH2][13C](=O)ON1C(=O)CCC1=O.CCC1CCC[15N]1[13CH2]C(=O)[15NH]CC[13C](=O)[15NH][13CH2][13CH2][13C](=O)ON1C(=O)CCC1=O.[13CH3]CC1CCCN1[13CH2]C(=O)[15NH]CC[13C](=O)[15NH][13CH2][13CH2][13C](=O)ON1C(=O)CCC1=O.[13CH3]CC1CCC[15N]1[13CH2][13C](=O)NCCC(=O)[15NH][13CH2][13CH2][13C](=O)ON1C(=O)CCC1=O.[13CH3][13CH2]C1CCCN1[13CH2][13C](=O)NCCC(=O)[15NH][13CH2][13CH2][13C](=O)ON1C(=O)CCC1=O.[13CH3][13CH2]C1CCC[15N]1[13CH2]C(=O)NCCC(=O)[15NH][13CH2][13CH2][13C](=O)ON1C(=O)CCC1=O.
What is the InChIKey of (2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethylpyrrolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](1,2,3-13C3)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate?
The InChIKey is HHPBCHWONHUMDP-UBQNWZMVSA-N. The full InChI is InChI=1S/8C18H28N4O6/c8*1-2-13-4-3-11-21(13)12-15(24)20-9-7-14(23)19-10-8-18(27)28-22-16(25)5-6-17(22)26/h8*13H,2-12H2,1H3,(H,19,23)(H,20,24)/i8+1,10+1,14+1,15+1,18+1,19+1,20+1,21+1;8+1,10+1,12+1,14+1,18+1,19+1,20+1,21+1;8+1,10+1,12+1,14+1,15+1,18+1,19+1,20+1;7+1,8+1,9+1,10+1,14+1,18+1,19+1,20+1;1+1,8+1,10+1,12+1,15+1,18+1,19+1,21+1;1+1,8+1,10+1,12+1,14+1,18+1,19+1,20+1;1+1,2+1,8+1,10+1,12+1,18+1,19+1,21+1;1+1,2+1,8+1,10+1,12+1,15+1,18+1,19+1.
What are the key properties of (2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethylpyrrolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](1,2,3-13C3)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate?
(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethylpyrrolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](1,2,3-13C3)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate has a molecular weight of 3235.08 g/mol, XLogP of -4.16, 80 rotatable bonds, 16 hydrogen bond donors, and 56 hydrogen bond acceptors.
Where does this data come from?
All data for (2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethyl(115N)azolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethyl(115N)azolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(1,2-13C2)ethylpyrrolidin-1-yl)acetyl]amino]propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](1,2,3-13C3)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate;(2,5-dioxopyrrolidin-1-yl) 3-[3-[[2-(2-(213C)ethylpyrrolidin-1-yl)acetyl](15N)amino](113C)propanoyl(15N)amino](1,2,3-13C3)propanoate is sourced from PubChem (CID 158481678), the world's largest open chemistry database maintained by the National Library of Medicine (NIH).