Radioiodination and . biodistribution of NBNPQD (2-benzyl-1-oxo-1,2-dihydropyrido[4,3-b]quinoxaline 5,10-dioxide) in tumor bearing mice_

NBNPQD (2-benzyl-1-oxo-1,2-dihydropyrido[4,

3-b]quinoxaline 5,10-dioxide) is a new synthesized quinoxaline

derivative. It could be labeled with auger emitter 125I

successfully with yield about 90 %. The labeled product was

evaluated by electrophoresis and thin layer chromatography.

Factors affected labeling yield were studied. 125I-NBNPQD

was stable up to 48 h post labeling. Biodistribution study of

125I-NBPQD in normal and tumor bearing mice was also

conducted. The biodistribution data revealed that 125INBNPQD

diffused rapidly to tumor sites in both ascites and

solid tumor bearing mice. 125I-NBNPQD was declined rapidly

from most of organs but slowly from tumor sites. In vitro

radiotoxicity of 125I-NBNPQDincreased with the increase of

its radioactivity. This study encourages the possible use of

125I-NBNPQD in tumor imaging and treatment. It also

encourages further studies on the chemotherapeutic activity

of NBNPQD hoping to get a new potent antitumor agent.

Keywords Quinoxaline _ Labeling _ Tumor _

Biodistribution _ Radiotoxicity