Radioactive iodine exchange reaction of HIPDM: kinetics and mechanism

Journal Article · Sun Mar 01 04:00:00 EST 1987 · J. Nucl. Med.; (United States)

OSTI ID:6862914

Lui, B; Chang, J; Sun, J S; Billings, J; Steves, A; Ackerhalt, R; Molnar, M; Kung, H F

In conjunction with single photon emission computed tomography (SPECT), iodine-123 (/sup 123/I)-labeled N,N,N'-trimethyl-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine (HIPDM) has been used clinically as a regional cerebral perfusion imaging agent. The (/sup 123/I)HIPDM can be prepared by a simple aqueous exchange reaction in a kit form. We synthesized unlabeled HIPDM by condensation of 2-hydroxy-3-methyl-5-iodobezaldehyde and N,N,N'-trimethyl-1,3-propanediamine, followed by a sodium borohydride reduction reaction. The kinetics of the radioactive iodine exchange reaction for the preparation of (/sup 123/I)HIDM is controlled by the pH, the temperature, and the presence of reductant (sodium bisulfite), and oxidant (sodium iodate). The reaction is a second order iodine-iodine exchange with an activation energy of 30.6 kcal/mole. The mechanism of this reaction probably involves the formation of an active 1+ or iodine free radical, which is sensitive to the presence of a reductant, such as sodium bisulfite.

• Research Organization: Beijing Normal Univ., China
• OSTI ID: 6862914
• Journal Information: J. Nucl. Med.; (United States), Journal Name: J. Nucl. Med.; (United States) Vol. 3; ISSN JNMEA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
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62 RADIOLOGY AND NUCLEAR MEDICINE
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CENTRAL NERVOUS SYSTEM
CHEMICAL PREPARATION
DRUGS
IN VITRO
KINETICS
LABELLED COMPOUNDS
NERVOUS SYSTEM
ORGANS
RADIOPHARMACEUTICALS
REACTION KINETICS
SYNTHESIS