Synthesis of leukotriene B4 antagonists labeled with In-111 or Tc-99m to image infectious and inflammatory foci

Broekema, M., van Eerd, J.J.E.M., Oyen, W.J.G., Corstens, F.H.M., Liskamp, R.M.J. , Boerman, O.C. and Harris, T.D. (2005) Synthesis of leukotriene B4 antagonists labeled with In-111 or Tc-99m to image infectious and inflammatory foci. Journal of Medicinal Chemistry, 48(20), pp. 6442-6453. (doi: 10.1021/jm050383h)

Abstract

In previous studies we demonstrated that lipophilic ⁹⁹mTc-labeled LTB4 antagonist 1 (RP517) accumulated in infectious foci in rabbits, but hepatobiliary clearance hampered imaging of abdominal lesions. We now report the use of cysteic acid as a pharmacokinetic modifier to improve the water solubility and renal clearance of three hydrophilic analogues of 1. Divalent LTB4 antagonist 17 (DPC11870-11) is a DTPA conjugate for radiolabeling with In-111. Monovalent LTB4 antagonists 15 (BMS57868-88) and divalent LTB4 antagonist 18 (BMS57868-81) are conjugated to bifunctional chelator HYNIC for radiolabeling with ⁹⁹mTc. The three compounds labeled efficiently with 111In or ⁹⁹mTc with high radiochemical purity and specific activities. Scintigraphic images obtained in New Zealand White rabbits having acute intramuscular E. coli infection demonstrated that all agents were able to clearly visualize the abscess, and clearance was exclusively renal. The biodistribution of the ⁹⁹mTc-labeled LTB4 antagonists was affected by the coligands used with the HYNIC chelator and by the monovalent or divalent nature of the receptor binding moiety. The best scintigraphic images were obtained with monovalent HYNIC conjugate 15 using tricine and isonicotinic acid as coligands with HYNIC for coordination with ⁹⁹mTc.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Liskamp, Professor Robert
• Authors: Broekema, M., van Eerd, J.J.E.M., Oyen, W.J.G., Corstens, F.H.M., Liskamp, R.M.J., Boerman, O.C., and Harris, T.D.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Journal of Medicinal Chemistry
• ISSN: 0022-2623