Synthesis and bio evaluation of a new fatty acid derivative labelled with technetium‐99m

Abstract

Abstract123I‐iodophenylpentadecanoic acid (IPPA) and 123I‐beta‐methyliodophenylpentadecanoic acid (BMIPP) are radiolabelled fatty acid derivatives used for assessment of myocardial viability. Because of limited accessibility of 123I in the clinical scenario, a 99m‐technetium‐based agent would be more advantageous. In this context, a xanthate derivative of 15‐hydroxypentadecanoic acid (HPDA) was synthesized for radiolabelling with [99mTcN]2+ intermediate.Direct reaction of the HPDA with carbon disulphide in presence of crushed sodium hydroxide in dry tetrahydrofuran resulted in moderate yield of the desired xanthate product. The prepared ligand was radiolabelled with [99mTcN]2+ intermediate and the resultant complex was characterized by paper electrophoresis and HPLC. The labelled preparation was assessed for its myocardial extraction and retention characteristics using Swiss mice model.The HPDA xanthate derivative was obtained in a low yield of ∼30%. Labelling via the [99mTcN]2+intermediate gave more than 95% complexation. During in vivo studies with the [TcN]2+ labelled complex maximum heart uptake observed was 3.10%ID/g at 5 min p.i., which cleared out rapidly, with retention of 0.79%ID/g of the activity at 60 min p.i.The 99mTcN‐HPDA xanthate derivative showed some uptake in the heart but rapid wash out and substantial uptake in the background organs (blood, liver and lungs) led to unfavourable critical ratios at all the time points of study. Copyright © 2006 John Wiley & Sons, Ltd.