{
  "abstract": "[18F]Rho6G-DEG-F is a rhodamine-based PET radiotracer for myocardial perfusion imaging (MPI) that exhibits excellent first-pass myocardial extraction, persistent cardiac retention, and high heart : liver ratios in rats and pigs. However, in human volunteers, heart : liver contrast was suboptimal. The primary goals of this study were to design an [18F]Rho6G-DEG-F analogue of attenuated lipophilicity for radiolabelling via nucleophilic heteroaromatic 18F-fluorination ([18F]Rho6G-DEG-Py-F; [18F]6), and to evaluate [18F]6 in rats and mice. To that end, precursors bearing 2-nitro- (5) and 2-trimethylammonium triflate (8)- pyridine groups were prepared in overall yields of 48% and 29%, starting from rhodamine 6G; final purification did not require C18 chromatography. Manual standard radiofluorination conditions (TEA[18F]F/TEAHCO3/DMSO/160 °C/20 min) afforded a best decay-corrected radiochemical yield (DC-RCY) of 31% from 5 and 7% from 8. In the latter case, precursor and radiotracer were easily separated by HPLC (molar activity = 33 ± 8 GBq per µmol). Upon translation to an automated synthesizer, [18F]6 was obtained in DC-RCYs of 9.3% and 0.7% from 5 and 8 respectively; best molar activities were 50 and 144 GBq per µmol respectively. [18F]Rho6G-DEG-Py-F exhibited complete stability in rat and mouse serum over 120 min (37 °C). A radiometabolite assay in two rats showed differing metabolic profiles between sexes, but similar % intact tracer at 60 min (32–34%). Micro-PET imaging in rats demonstrated extended myocardial retention (SUV > 1.0 at 120 min), gradual liver washout, and high heart : liver ratios (3.7 in male, 2.5 in female at 120 min); however, similar experiments in mice revealed low heart uptake and rapid metabolism (SUV ∼ 0.3; heart : liver ratio = 1.0 at 120 min).",
  "abstract_shown": true,
  "affiliations": [
    "McMaster University, Department of Chemistry and Chemical Biology Hamilton ON L8S 4M1 Canada",
    "Brain Health Imaging Centre, Centre for Addiction and Mental Health Toronto ON M5T 1R8 Canada",
    "Department of Psychiatry, University of Toronto Toronto ON M5T1R8 Canada"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Maya Mahmood",
      "orcid": "0009-0004-1511-0509"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Emily Murrell",
      "orcid": "0000-0002-9546-681X"
    },
    {
      "affs": [
        0
      ],
      "name": "Seniha Ozyuncu"
    },
    {
      "affs": [
        1
      ],
      "name": "Junchao Tong"
    },
    {
      "affs": [
        0
      ],
      "name": "Angelina Lui"
    },
    {
      "affs": [
        0
      ],
      "name": "James A. H. Inkster",
      "orcid": "0000-0001-5977-7349"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/99rc0bpqd5rsp.bib",
  "cited_by": 0,
  "doi": "10.1039/d6ra08884h",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13738243/",
  "id": "99rc0bpqd5rsp",
  "issns": [
    "2046-2069"
  ],
  "landing_url": "https://doi.org/10.1039/d6ra08884h",
  "language": "en",
  "licence": "CC-BY-3.0",
  "licence_label": "CC BY 3.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/3.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Chemistry"
    ],
    [
      "openalex",
      "2741|Radiopharmaceutical Chemistry and Applications"
    ]
  ],
  "openalex": "W7225308203",
  "pdf_url": null,
  "pmcid": "PMC13738243",
  "pmid": "42991686",
  "published": "2026-11-05",
  "publisher": "Royal Society of Chemistry",
  "ris": "https://research.draconitic.com/paper/99rc0bpqd5rsp.ris",
  "sources": [
    {
      "first_seen": "2026-11-09T12:23:16Z",
      "native_id": "PMC13738243",
      "source": "pmc",
      "url": "https://doi.org/10.1039/d6ra08884h"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2741|Radiopharmaceutical Chemistry and Applications",
      "subfield": "imaging"
    }
  ],
  "title": "Synthesis and preclinical evaluation of a novel 2-[18F]fluoropyridine-bearing rhodamine for myocardial perfusion imaging with PET",
  "title_text": "Synthesis and preclinical evaluation of a novel 2-[18F]fluoropyridine-bearing rhodamine for myocardial perfusion imaging with PET",
  "type": "peer-reviewed",
  "updated_at": "2026-11-09T12:23:16Z",
  "url": "https://research.draconitic.com/paper/99rc0bpqd5rsp",
  "venue": "RSC Advances",
  "versions": []
}