Abstract:
INTRODUCTION:Thymidylate synthase and folate receptors are well-developed targets of cancer therapy. Discovery of a simple and fast method for the conversion of 11CH3Ito[11C]-formaldehyde (11CH2O) encouraged us to label the co-factor of this enzyme. Preliminary studies conducted on cell lines have demonstrated a preferential uptake of [11-14C]-(R)-N5,N10-methylene-5,6,7,8-tetrahydrofolate (14CH2H4folate) by cancerous cell vs. normal cells from the same organ (Saeed M., Sheff D. and Kohen A. Novel positron emission tomography tracer distinguishes normal from cancerous cells. J Biol Chem 2011;286:33872-33878), pointing out 11CH2H4folate as a positron emission tomography (PET) tracer for cancer imaging. Herein we report the synthesis of 11CH2H4folate, which may serve as a potential PET tracer. METHODS:In a remotely controlled module, methyl iodide (11CH3I) was bubbled into a reaction vial containing trimethylamine N-oxide in N,N-Dimethylformamide (DMF) and heated to 70°C for 2 min. Formaldehyde (11CH2O) formed after the completion of reaction was then mixed with a solution of freshly prepared tetrahydrofolate (H4folate) by using a fast chemoenzymatic approach to accomplish synthesis of 11CH2H4folate. Purification of the product was carried out by loading the crude reaction mixture on a SAX cartridge, washing with water to remove unbound impurities and finally eluting with a saline solution. RESULTS:The synthesis and purification of 11CH2H4folate were completed within 5 min. High-performance liquid chromatography analysis of the product after SAX purification indicates that more than 90% of the radioactivity that was retained on the SAX cartridge was in 11CH2H4folate, with minor (<10%) radioactivity due to unreacted 11CH2O. CONCLUSION:We present a fast (∼5 min) synthesis and purification of 11CH2H4folate as a potential PET tracer. The final product is received in physiologically compatible buffer (100 mM sodium phosphate, pH 7.0 containing 500 mM NaCl) and ready for use in vivo.
journal_name
Nucl Med Bioljournal_title
Nuclear medicine and biologyauthors
Saeed M,Tewson TJ,Erdahl CE,Kohen Adoi
10.1016/j.nucmedbio.2011.12.003subject
Has Abstractpub_date
2012-07-01 00:00:00pages
697-701issue
5eissn
0969-8051issn
1872-9614pii
S0969-8051(11)00305-2journal_volume
39pub_type
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journal_title:Nuclear medicine and biology
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journal_title:Nuclear medicine and biology
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pub_type: 杂志文章,评审
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pub_type: 杂志文章
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更新日期:1999-08-01 00:00:00
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pub_type: 杂志文章
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journal_title:Nuclear medicine and biology
pub_type: 杂志文章
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journal_title:Nuclear medicine and biology
pub_type: 杂志文章
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pub_type: 杂志文章
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journal_title:Nuclear medicine and biology
pub_type: 杂志文章
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journal_title:Nuclear medicine and biology
pub_type: 杂志文章
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journal_title:Nuclear medicine and biology
pub_type: 杂志文章
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更新日期:2000-01-01 00:00:00
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journal_title:Nuclear medicine and biology
pub_type: 杂志文章
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更新日期:2014-01-01 00:00:00
abstract::To evaluate the ability of [1-11C]octanoate as a PET tracer for imaging the brain, we examined its distribution in the brain and surrounding tissues in rats and cats with PET. In rats, owing to the accumulated radioactivity in the harderian glands, clear brain images were not obtained at rostral levels. In cats, the b...
journal_title:Nuclear medicine and biology
pub_type: 杂志文章
doi:10.1016/s0969-8051(96)00148-5
更新日期:1996-11-01 00:00:00
abstract:INTRODUCTION:Current guidelines for brain PET imaging advice against the injection of diazepam prior to brain FDG-PET examination in order to avoid possible interactions of benzodiazepines with the radiotracer uptake. Nevertheless, many patients undergoing PET studies are likely to be under chronic treatment with benzo...
journal_title:Nuclear medicine and biology
pub_type: 杂志文章
doi:10.1016/j.nucmedbio.2016.09.001
更新日期:2016-12-01 00:00:00
abstract:UNLABELLED:The purpose of this study was to compare the diagnostic value of positron emission tomography (PET) using [(18)F]-fluorodeoxyglucose ((18)F-FDG) and O-(2-[(18)F]fluoroethyl)-l-tyrosine ((18)F-FET) in patients with brain lesions suspicious of cerebral gliomas. METHODS:Fifty-two patients with suspicion of cer...
journal_title:Nuclear medicine and biology
pub_type: 临床试验,杂志文章
doi:10.1016/j.nucmedbio.2009.05.005
更新日期:2009-10-01 00:00:00