Comparison of Vanillic Acid with its Parent Ferulic Acid as Tumor Targeting Agents: TLC Densitometric Determination, Radiolabeling and Biological Evaluation

Recently, the anticancer activity of vanillic acid (VA) and its parent ferulic acid (FA) which is a caffeic acid derivative has been reported. Therefore, in this study VA and FA were radiolabelled with ¹³¹I to explore its potential as a tumor targeting agent. The radiolabeling process was carried out via electrophilic substitution reaction. The factors affecting labeling yield were optimized and the radiochemical purity (RCP) was assessed by various analytical techniques including paper chromatography (PC), thin layer chromatography (TLC), instant thin layer chromatography (ITLC), paper electrophoresis (PE) and highperformance liquid chromatography (HPLC). Biodistribution studies of ¹³¹I-VA and ¹³¹I-FA were performed on tumor bearing mice. The radiolabeling yield of ¹³¹I-VA and ¹³¹I-FA was 96.23 ± 0.45 and 97.62 ± 0.8 % and the miniaturized chromatographic systems showed high efficacy in RCP evaluation comparable to the conventional ones. Mini-TLC was proved to be specific, accurate, precise and linear. The tumor uptake of ¹³¹I-FA in solid tumor bearing mice was 4.35 ± 0.41 ID/g at 60 min with 2.79 as a tumor/muscle ratio while that for ¹³¹I-VA was 6.48 ± 0.69 ID/g at 30 min with 2.88 as a tumor/muscle ratio. Consequently, ¹³¹I-VA and ¹³¹I-FA could be used as a tumor targeting agent for nuclear medicine applications and the fast reaction monitoring could be achieved using miniaturized chromatographic techniques.