A radiopaque compound,
namely, 4,4-bisÂ(4-hydroxy-3,5-diiodophenyl)Âpentanoic
acid, was synthesized by the electrophilic aromatic iodination of
4,4-bisÂ(4-hydroxyphenyl)Âpentanoic acid using sodium iodide and sodium
hypochlorite. The active iodines created by hypochlorite were selectively
bound to the ortho positions of the diphenolic acid and obtained a
tetraiodo compound. Characterization of this iodinated compound was
accomplished by routine methods such as Fourier transform infrared
(FTIR)
spectroscopy, 1H nuclear magnetic resonance (NMR) spectroscopy,
energy-dispersive X-ray spectroscopy, mass spectroscopy, UV–Vis
spectroscopy, and thermogravimetry. The iodine content in the compound
was as high as 64% by weight and therefore expected to possess substantial
radiopacity. A 5% solution of the compound in dimethyl sulfoxide exhibited
radiopacity of 885 ± 7 Hounsfield Units when tested with computed
tomography (CT) scanner. In vitro cytotoxicity test performed using
3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)
assay demonstrated that the compound was noncytotoxic to L929 fibroblast
cells up to the level of 0.8 mg/mL concentration. Overall results
indicate that this highly radiopaque compound has the potential to
be used for X-ray imaging in the clinical scenario.