title: Radiosynthesis of [18F]-fluorobenzoate-doxorubicin Using Acylation Approach.
abstract: BACKGROUND
  Previously, we have labeled doxorubicin with [99Tc] and evaluated its potential as a SPECT agent to detect cancer in tumor bearing mice. In this study, we sought to radiolabel doxorubicin with [18F] using acylation method.
  
  
  METHODS
  A quaternary salt of the precursor pentamethylbenzyl-4-(trimethylammonium trifluoromethanesulfonate) benzoate was synthesized and characterized by 1H-NMR. As a first step, 4-[18F]- fluorobenzoic acid (FBA) was synthesized from precursor. In second step, [18F]-FBA was further converted to its corresponding acyl form to radiolabel doxorubicin via acylation reaction.
  
  
  RESULTS
  The total reaction time for the synthesis of [18F]-fluorobenzoate-doxorubicin was about 60 minutes. The radiolabeling efficiency of the final product was estimated to be about 59.0% The radiochemical yield for the synthesis of [18F]-FBA and [18F]-fluorobenzoate-doxorubicin were 19.0- 29.0% and 12.0-14.0% respectively.
  
  
  CONCLUSIONS
  Radio synthesis of [18F]-fluorobenzoate-doxorubicin by acylation is a convenient method. However, further improvement in the labeling strategy is required to increase the radiolabeling efficiency and radio synthesis yield. Also, the radiolabeled product needs a detailed pre-clinical evaluation.
authors.forename: Pardeep
authors.initials: P
authors.lastname: Kumar
authors.forename: Ankit
authors.initials: A
authors.lastname: Watts
authors.forename: Pratap
authors.initials: P
authors.lastname: Acharya
authors.forename: Ranju
authors.initials: R
authors.lastname: Bansal
authors.forename: Anchal
authors.initials: A
authors.lastname: Ghai
authors.forename: Amritjyot
authors.initials: A
authors.lastname: Kaur
authors.affiliation: Department of Nuclear Medicine and PET, Postgraduate Institute of Medical Education and Research, Chandigarh-160012, India.
authors.forename: Baljinder
authors.initials: B
authors.lastname: Singh
mesh_terms: D000215:Acylation; D004317:Doxorubicin / Q000737:chemistry*; D005462:Fluorine Radioisotopes / Q000737:chemistry*; D007553:Isotope Labeling; D011854:Radiochemistry; D019275:Radiopharmaceuticals / Q000138:chemical synthesis*; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D004317:Doxorubicin
keywords: Acylation; PET; doxorubicin; fluorine-18; radiolabeling; radiosynthesis.