Gadobenic acid

Gadobenic acid (INN, brand name Multihance) is a complex of gadolinium with the ligand BOPTA. In the form of the methylglucamine salt meglumine gadobenate (INNm) or gadobenate dimeglumine (USAN), it is used as a gadolinium-based MRI contrast medium.^[4]

Gadobenic acid

Clinical data
Trade names	Multihance
Other names	gadobenate dimeglumine (USAN US)
AHFS/Drugs.com	Professional Drug Facts
ATC code	V08CA08 (WHO)
Legal status
Legal status	CA: ℞-only[1] UK: POM (Prescription only)[2] US: ℞-only[3]
Identifiers
IUPAC name dihydrogen [(±)-4-carboxy-5,8,11-tris(carboxymethyl)-1-phenyl-2-oxa-5,8,11-triazatridecan-13-oato(5−)]gadolinate(2−).
CAS Number	113662-23-0 N
PubChem CID	105124
DrugBank	DB00743 N
ChemSpider	94843 N
UNII	15G12L5X8K
KEGG	D08018 Y
ChEMBL	ChEMBL1200571 N
CompTox Dashboard (EPA)	DTXSID00921145
Chemical and physical data
Formula	C22H28GdN3O11
Molar mass	667.73 g·mol−1
3D model (JSmol)	Interactive image
SMILES [H+].[H+].[Gd+3].[O-]C(=O)CN(CC([O-])=O)CCN(CC([O-])=O)CCN(CC([O-])=O)C(C([O-])=O)COCc1ccccc1
InChI InChI=1S/C22H31N3O11.Gd/c26-18(27)10-23(6-7-24(11-19(28)29)12-20(30)31)8-9-25(13-21(32)33)17(22(34)35)15-36-14-16-4-2-1-3-5-16;/h1-5,17H,6-15H2,(H,26,27)(H,28,29)(H,30,31)(H,32,33)(H,34,35);/q;+3/p-3 N Key:MXZROTBGJUUXID-UHFFFAOYSA-K N
NY (what is this?)  (verify)

BOPTA is a derivative of DTPA in which one terminal carboxyl group, –C(O)OH is replaced by -C–O–CH₂C₆H₅. Thus gadobenic acid is closely related to gadopentetic acid. BOPTA itself was first synthesized in 1995.^[5] In the "gadobenate" ion gadolinium ion is 9-coordinate with BOPTA acting as an 8-coordinating ligand. The ninth position is occupied by a water molecule, which exchanges rapidly with water molecules in the immediate vicinity of the strongly paramagnetic complex, providing a mechanism for MRI contrast enhancement. ¹³⁹La NMR studies on the diamagnetic La-BOPTA²⁻ complex suggest that the Gd complex maintains in solution the same kind of coordination as found, by X-ray crystallography, in the solid state for Gd-BOPTA disodium salt.^[5]