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1.
[18F]FDG (2-deoxy-2-[18F]fluoro-d-glucose) was fed to a sorghum plant [Sorghum bicolor (L.) Moench] from the tip of a leaf and its movement was monitored using a planar positron imaging system (PPIS). [18F]FDG was uptaken from the leaf tip and it was translocated to the basal part of the shoots from where it moved to the roots,
the tillers and the sheaths. Autoradiographic analysis of the distribution of 18F, [18F]FDG and/or its metabolites showed translocation to the roots, tillers, and to the leaves that were younger than the supplied
leaf. Strong labelling was observed in the basal part of the shoots, in the sheaths, the youngest leaf and the root tips.
Our results indicate that [18F]FDG and/or its metabolites were absorbed from the leaf and translocated to the sites where nutrients are required. This
strongly suggests that [18F]FDG can be utilised as a tracer to study photoassimilate translocation in the living plant. This is the first report on
the use of [18F]FDG, which is routinely used as a probe for clinical diagnosis, to study source to sink translocation of metabolites in
whole plants in real time. 相似文献
2.
Fujinaga M Yamasaki T Kawamura K Kumata K Hatori A Yui J Yanamoto K Yoshida Y Ogawa M Nengaki N Maeda J Fukumura T Zhang MR 《Bioorganic & medicinal chemistry》2011,19(1):102-110
The purpose of this study was to synthesize 6-[1-(2-[18F]fluoro-3-pyridyl)-5-methyl-1H-1,2,3-triazol-4-yl]quinoline ([18F]FPTQ, [18F]7a) and to evaluate its potential as a positron emission tomography ligand for imaging metabotropic glutamate receptor type 1 (mGluR1) in the rat brain. Compound [18F]7a was synthesized by [18F]fluorination of 6-[1-(2-bromo-3-pyridyl)-5-methyl-1H-1,2,3-triazol-4-yl]quinoline (7b) with potassium [18F]fluoride. At the end of synthesis, 1280-1830 MBq (n = 8) of [18F]7a was obtained with >98% radiochemical purity and 118-237 GBq/??mol specific activity using 3300-4000 MBq of [18F]F−. In vitro autoradiography showed that [18F]7a had high specific binding with mGluR1 in the rat brain. Biodistribution study using a dissection method and small-animal PET showed that [18F]7a had high uptake in the rat brain. The uptake of radioactivity in the cerebellum was reduced by unlabeled 7a and mGluR1-selective ligand JNJ-16259685 (2), indicating that [18F]7a had in vivo specific binding with mGluR1. Because of a low amount of radiolabeled metabolite present in the brain, [18F]7a may have a limiting potential for the in vivo imaging of mGluR1 by PET. 相似文献
3.
Iddon L Leyton J Indrevoll B Glaser M Robins EG George AJ Cuthbertson A Luthra SK Aboagye EO 《Bioorganic & medicinal chemistry letters》2011,21(10):3122-3127
A novel class of alkyne linked [Tyr3]octreotate analogues have been labelled by a copper catalysed azide-alkyne cycloaddition reaction (CuAAC) to form a 1,4-substituted triazole using the reagent [18F]2-fluoroethyl azide. An unexpected variability in reactivity during the CuAAC reaction was observed for each alkyne analogue which has been investigated. Two lead alkyne linked [Tyr3]octreotate analogues, G-TOCA (3a) and βAG-TOCA (5a) have been identified to be highly reactive in the click reaction showing complete conversion to the [18F]2-fluoroethyl triazole linked [Tyr3]octreotate analogues FET-G-TOCA (3b) and FET-βAG-TOCA (5b) under mild conditions and with short synthesis times (5 min at 20 °C). As well as ease of synthesis, in vitro binding to the pancreatic tumour AR42J cells showed that both FET-G-TOCA and FET-βAG-TOCA have high affinity for the somatostatin receptor with IC50 of 4.0 ± 1.4, and 1.6 ± 0.2 nM, respectively. 相似文献
4.
Peng He Bing Zhang Yuan Zou Yan Zhang Zhihao Zha Yali Long Jia Qiu Wanqing Shen Xiaoping Lin Zhoulei Li Xiangsong Zhang 《Translational oncology》2021,14(5)
L-ascorbic acid (AA) was reported to have an anti-cancer effect over 40 years. In recent years, several ongoing clinical trials are exploring the safety and efficacy of intravenous high-dose AA for cancer treatment. The lack of appropriate imaging modality limits the identification of potentially suitable patients for AA treatment. This study focuses on identifying AA-sensitive tumor cells using molecular imaging. 6-Deoxy-6-[18F] fluoro-L-ascorbic Acid (18F-DFA), a structural analog of AA, was synthesized and labeled to visualize the metabolism of AA in vivo. Colorectal cancer (CRC) cell lines with high and low expression of sodium-dependent vitamin C transporters 2 (SVCT2) were used for a series of cellular uptake tests. PET imaging was performed on xenograft tumor-bearing mice. More AA uptake was observed in CRC cells with high SVCT2 expression than in cells with low SVCT2 expression. The substrate (unlabeled AA) can competitively inhibit the 18F-DFA tracer uptake by CRC cells. The biodistribution of 18F-DFA in mice showed high radioactivity was seen in organs such as adrenal glands, kidneys, and liver that were known to have high concentrations of AA. Both PET imaging and tissue distribution showed that cancer cells with high SVCT2 expression enhanced the accumulation of 18F-DFA in mice after tumor formation. Immunohistochemistry was used to verify the corresponding results. As a radiotracer, 18F-DFA can provide powerful imaging information to identify tumor with high affinity of AA, and SVCT2 can be a potential biomarker in this process. 相似文献
5.
《International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology》1989,16(5):449-453
Rats with mammary cancer were imaged by scintigraphy: 10 rats with 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) and 10 rats with [18F]F-d-galactose. The uptake of both tracers was similar in the tumors—the tumor-to-normal tissue ratio was 2.7 ± 1.1 for [18F]FDG and 2.3 ± 0.9 for [18F]FDGal at 120 min after injection. In addition to the tumors [18F]FDG accumulated in the brain, bladder and heart, [18F]FDGal in the brain, bladder and liver. [18F]FDGal may be useful for tumor imaging in man; further studies should be addressed to elucidate the mechanism of [18F]FDGal uptake into tumors. 相似文献
6.
The MPTP-lesioned monkey is considered as the best animal model for Parkinson’s disease (PD). It has damage to dopaminergic cell groups and motor dysfunction similar to that seen in PD. Correlations between these two parameters have been described but there is a lack of formal statistical analyses on dopaminergic function as assessed by [18F]-F-DOPA PET and objectively rated motor behavior in longitudinal experiments. 相似文献
7.
Jordan Shaun Bankiewicz Krzysztof S. Eberling Jamie L. VanBrocklin Henry F. O'Neil James P. Jagust William J. 《Neurochemical research》1998,23(4):513-517
In vivo brain microdialysis was used to monitor 6-[18F]fluoro-L-m-tyrosine (FMT) uptake and metabolism in the striatum of conscious freely moving rats for 3 hours after FMT injection (25 mg/kg, iv). Microdialysate collected 20 to 120 min post-dose, contained FMT at a concentration (0.2 to 0.3 nM) approximately ten-fold below that of its metabolite [18F]fluoro-3-hydroxyphenylacetic acid (FPAC; 3.2 to 3.3 nM). D-amphetamine (2.5 mg/kg, i.p.) injected 120 min after significantly increased microdialysate FPAC (3.27 ± 0.31 nM to 4.51 ± 0.45 nM) in control but not reserpinized rats. Taken together these data demonstrate FMT is heavily metabolized following its entry into the striatum yielding FPAC which appears to be stored, at least in part, in reserpine sensitive cytoplasmic vesicles. Presynaptic retention of FPAC may contribute to the preferential accumulation of FMT positron emission tomography (PET) signaling in dopaminergic brain areas. 相似文献
8.
《International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology》1988,15(3):271-276
To investigate the highest accumulation of 2-deoxy-2-[18F]fluoro-d-galactose ([18F]FdGal) in the liver, metabolic studies with [18F]FdGal were carried out in Wistar rats for 120 min after i.v. injection. As main metabolites 2-deoxy-2-[18F]fluoro-d-galactose 1-phosphate ([18F]FdGal-1-P) and UDP-2-deoxy-2-[18F]-fluoro-d-galactose (UDP-[18F]FdGal) were identified in the liver and other tissues. The [18F]FdGal was phosphorylated by galactokinase. The phosphorylation rate was very rapid in the liver, in which at 5 min after injection 81% of 18F was detected as [18F]FdGal-1-P. After this time the phosphate form decreased with time, which was explained by conversion of [18F]FdGal-1-P to UDP-[18F]FdGal by UDP-glucose: galactose-1-phosphate uridyltransferase. At 120 min after injection 77% of the 18F was measured in the UDP-[18F]FdGal. In the brain both reaction rates were slower than in the liver. Both phosphate and uridylate derivates were also observed as main metabolites in the heart, lung, spleen and small intestine. On the other hand, a small amount of [18F]FdGal-1-P was detected in the plasma, in which the percentage of phosphate increased gradually and was 6% at 120 min.These results show that the [18F]FdGal metabolism in tissue results in phosphate and uridylate trapping and that the [18F]FdGal has potential for measuring in vivo galactose metabolism with positron emission tomography. 相似文献
9.
Purpose[18F]Fluoromethylcholine ([18F]FMCH) is a radiopharmaceutical used in positron emission tomography (PET) imaging for the study of prostate, breast, and brain tumors. It is usually synthesized in cyclotron facilities where 18F is produced by proton irradiation of [18O]H2O through 18O(p,n)18F reaction. Due to the activation of target materials, the bombardment causes unwanted radionuclidic impurities in [18O]H2O, that need to be removed during the radiopharmaceutical synthesis. Thus, the aim of this study is to quantify the radionuclide impurities in the 18F production process and in the synthesized [18F]FMCH, demonstrating the radionuclidic purity of this radiopharmaceutical.MethodsLong-lived radionuclide impurities were experimentally assessed using high-resolution gamma and liquid scintillation spectrometries, while short-lived impurities were monitored analyzing the decay curve of the irradiated [18O]H2O with an activity calibrator. As spectrometric radionuclide library, a Geant4 Monte Carlo simulation of the 18F-target assembly was previously performed.Results3H, 52,54Mn, 56,57,58Co, 95m,96Tc, 109Cd, and 184Re were found in the irradiated [18O]H2O, but no radionuclide was found in the non-irradiated [18O]H2O neither in the final [18F]FMCH solution with an activity concentration greater than the minimum detectable activity concentration. A total impurity activity <6.2 kBq was measured in the irradiated [18O]H2O, whereas a [18F]FMCH radionuclide purity >99.9999998% was estimated. Finally, the decay curve of the irradiated [18O]H2O revealed a very low maximum of 13N activity (<0.03% of 18F) even immediately after the end of bombardment.ConclusionsThis study demonstrated the radionuclidic purity of [18F]FMCH according to the EU Pharmacopeia. 相似文献
10.
Hashimoto Y Smith SP Pickford AR Bocquier AA Campbell ID Werner JM 《Journal of biomolecular NMR》2000,17(3):203-214
The structure of a pair of modules (6F11F2), that forms part of the collagen-binding region of fibronectin, is refined using heteronuclear relaxation data. A structure of the pair was previously derived from 1H-1H NOE and 3
J
HHN data [Bocquier et al. (1999) Structure, 7, 1451–1460] and a weak module–module interface, comprising Leu19 and Leu28, in 6F1, and Tyr68 in 2F1, was identified. In this study, the definition of the average relative orientation of the two modules is improved using the dependence of 15N relaxation on rotational diffusion anisotropy. This structure refinement is based on the selection of a subset of structures from sets calculated with NOE and 3
J
HHN data alone, using the quality of the fits to the relaxation data as the selection criterion. This simple approach is compared to a refinement strategy where 15N relaxation data are included in the force field as additional restraints [Tjandra et al. (1997) Nat. Struct. Biol., 4, 443–449]. 相似文献
11.
《International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology》1986,13(5):577-581
The activities of hexokinase and glucose-6-phosphatase, as well as the in vivo metabolic products of 2-[18F]fluoro-2-deoxyglucose ([18F]FDG) (45 min after an i.v. injection), were determined from several tissues of Rous sarcoma implanted rats. The HK/G-6-Pase ratio was found to be high in brain and tumor, and low in liver with intermediate values for kidney and muscle. In accordance with the measured enzyme activities about 90% of the 18F was found as [18F]FDG-6-P in brain, heart and tumor, whereas most of its was as [18F]FDG in liver and kidney. In addition three minor metabolites, tentatively identified as nucleotide-derivatives of [18F]FDG, were formed. Our results suggest that at least Rous sarcoma tumor effectively converts [18F]FDG to [18F]FDG-6-P and thus PET studies with [18F]FDG can be applied to tumor diagnosis and to quantitative measurement of glucose utilization in tumor tissue according to the model of Sokoloff.(9) 相似文献
12.
Martha Nowosielski Matthew D. DiFranco Daniel Putzer Marcel Seiz Wolfgang Recheis Andreas H. Jacobs Günther Stockhammer Markus Hutterer 《PloS one》2014,9(4)
Objectives
Intra-individual spatial overlap analysis of tumor volumes assessed by MRI, the amino acid PET tracer [18F]-FET and the nucleoside PET tracer [18F]-FLT in high-grade gliomas (HGG).Methods
MRI, [18F]-FET and [18F]-FLT PET data sets were retrospectively analyzed in 23 HGG patients. Morphologic tumor volumes on MRI (post-contrast T1 (cT1) and T2 images) were calculated using a semi-automatic image segmentation method. Metabolic tumor volumes for [18F]-FET and [18F]-FLT PETs were determined by image segmentation using a threshold-based volume of interest analysis. After co-registration with MRI the morphologic and metabolic tumor volumes were compared on an intra-individual basis in order to estimate spatial overlaps using the Spearman''s rank correlation coefficient and the Mann-Whitney U test.Results
[18F]-FLT uptake was negative in tumors with no or only moderate contrast enhancement on MRI, detecting only 21 of 23 (91%) HGG. In addition, [18F]-FLT uptake was mainly restricted to cT1 tumor areas on MRI and [18F]-FLT volumes strongly correlated with cT1 volumes (r = 0.841, p<0.001). In contrast, [18F]-FET PET detected 22 of 23 (96%) HGG. [18F]-FET uptake beyond areas of cT1 was found in 61% of cases and [18F]-FET volumes showed only a moderate correlation with cT1 volumes (r = 0.573, p<0.001). Metabolic tumor volumes beyond cT1 tumor areas were significantly larger for [18F]-FET compared to [18F]-FLT tracer uptake (8.3 vs. 2.7 cm3, p<0.001).Conclusion
In HGG [18F]-FET but not [18F]-FLT PET was able to detect metabolic active tumor tissue beyond contrast enhancing tumor on MRI. In contrast to [18F]-FET, blood-brain barrier breakdown seems to be a prerequisite for [18F]-FLT tracer uptake. 相似文献13.
Wenjiang Yang Tiantian Mou Cheng Peng Zhanhong Wu Xianzhong Zhang Fang Li Yunchuan Ma 《Bioorganic & medicinal chemistry》2009,17(21):7510-7516
Asialoglycoprotein receptors (ASGP-R) are well known to exist on the mammalian liver, situate on the surface of hepatocyte membrane. Quantitative imaging of asialoglycoprotein receptors could estimate the function of the liver. 99mTc labeled galactosyl-neoglycoalbumin (NGA) and diethylenetriaminepentaacetic acid galactosyl human serum albumin (GSA) have been developed for SPECT imaging and clinical used in Japan. In this study, we labeled the NGA with 18F to get a novel PET tracer [18F]FNGA and evaluated its hepatic-targeting efficacy and pharmacokinetics. Methods: NGA was labeled with 18F by conjugation with N-succinimidyl-4-18F-fluorobenzoate ([18F]SFB) under a slightly basic condition. The in vivo metabolic stability of [18F]FNGA was determined. Ex vivo biodistribution of [18F]FNGA and blocking experiment was investigated in normal mice. MicroPET images were acquired in rat with and without block at 5 min and 15 min after injection of the radiotracer (3.7 MBq/rat), respectively. Results: Starting with 18F− Kryptofix 2.2.2./K2CO3 solution, the total reaction time for [18F]FNGA is about 150 min. Typical decay-corrected radiochemical yield is about 8–10%. After rapid purified with HiTrap desalting column, the radiochemical purity of [18F]FNGA was more than 99% determined by radio-HPLC. [18F]FNGA was metabolized to produce [18F]FB-Lys in urine at 30 min. Ex vivo biodistribution in mice showed that the liver accumulated 79.18 ± 7.17% and 13.85 ± 3.10% of the injected dose per gram at 5 and 30 min after injection, respectively. In addition, the hepatic uptake of [18F]FNGA was blocked by pre-injecting free NGA as blocking agent (18.55 ± 2.63%ID/g at 5 min pi), indicating the specific binding to ASGP receptor. MicroPET study obtained quality images of rat at 5 and 15 min post-injection. Conclusion: The novel ASGP receptor tracer [18F]FNGA was synthesized with high radiochemical yield. The promising biological properties of [18F]FNGA afford potential applications for assessment of hepatocyte function in the future. It may provide quantitative information and better resolution which particularly help to the liver surgery. 相似文献
14.
Weiping Yu Larry Williams Vernon M. Camp Jeffrey J. Olson Mark M. Goodman 《Bioorganic & medicinal chemistry letters》2010,20(7):2140-2143
A new [18F] labeled amino acid anti-1-amino-2-[18F]fluoro-cyclobutyl-1-carboxylic acid 9 (anti-2-[18F]FACBC) was synthesized in 30% decay-corrected yield with high radiochemical purity over 99%. The cyclic sulfamidate precursor was very stable and highly reactive towards nucleophilic radiofluorination. Cell uptake assays with rat 9L gliosarcoma cells showed that [18F]9 was transported into tumor cells via multiple amino acid transport systems, including L and A systems. Biodistribution study in rats with intracranial 9L gliosarcoma tumors demonstrated that [18F]9 had a rapid and prolonged accumulation in tumors with 26:1 tumor to brain ratio at 120 min post-injection. In this model, [18F]9 is a potential PET tracer for brain tumor imaging. 相似文献
15.
Kazuhiko Yanamoto Katsushi Kumata Tomoteru Yamasaki Chika Odawara Kazunori Kawamura Joji Yui Akiko Hatori Kazutoshi Suzuki Ming-Rong Zhang 《Bioorganic & medicinal chemistry letters》2009,19(6):1707-1710
[18F]FEAC ([18F]4a) and [18F]FEDAC ([18F]4b) were developed as two novel positron emission tomography (PET) ligands for peripheral-type benzodiazepine receptor (PBR). [18F]4a and [18F]4b were synthesized by fluoroethylation of precursors 8a and 8b with [18F]FCH2CH2Br ([18F]9), respectively. Small-animal PET scan for a neuroinflammatory rat model showed that the two radioligands had high uptakes of radioactivity in the kainic acid-infused striatum, a brain region where PBR density was increased. 相似文献
16.
Fluorine atoms are often incorporated into drug molecules as part of the lead optimization process in order to improve affinity
or modify undesirable metabolic and pharmacokinetic profiles. From an NMR perspective, the abundance of fluorinated drug leads
provides an exploitable niche for structural studies using 19F NMR in the drug discovery process. As 19F has no interfering background signal from biological sources, 19F NMR studies of fluorinated drugs bound to their protein receptors can yield easily interpretable and unambiguous structural
constraints. 19F can also be selectively incorporated into proteins to obtain additional constraints for structural studies. Despite these
advantages, 19F NMR has rarely been exploited for structural studies due to its broad lines in macromolecules and their ligand complexes,
leading to weak signals in 1H/19F heteronuclear NOE experiments. Here we demonstrate several different experimental strategies that use 19F NMR to obtain ligand–protein structural constraints for ligands bound to the anti-apoptotic protein Bcl-xL, a drug target
for anti-cancer therapy. These examples indicate the applicability of these methods to typical structural problems encountered
in the drug development process. 相似文献
17.
Aristeidis Chiotellis Adrienne Müller Karin Weyermann Dominique S. Leutwiler Roger Schibli Simon M. Ametamey Stefanie D. Krämer Linjing Mu 《Amino acids》2014,46(8):1947-1959
Amino acid transport is an attractive target for oncologic imaging. Despite a high demand of cancer cells for cationic amino acids, their potential as PET probes remains unexplored. Arginine, in particular, is involved in a number of biosynthetic pathways that significantly influence carcinogenesis and tumor biology. Cationic amino acids are transported by several cationic transport systems including, ATB0,+ (SLC6A14), which is upregulated in certain human cancers including cervical, colorectal and estrogen receptor-positive breast cancer. In this work, we report the synthesis and preliminary biological evaluation of a new cationic analog of the clinically used PET tumor imaging agent O-(2-[18F]fluroethyl)-l-tyrosine ([18F]FET), namely O-2((2-[18F]fluoroethyl)methylamino)ethyltyrosine ([18F]FEMAET). Reference compound and precursor were prepared by multi-step approaches. Radiosynthesis was achieved by no-carrier-added nucleophilic [18F]fluorination in 16–20 % decay-corrected yields with radiochemical purity >99 %. The new tracer showed good stability in vitro and in vivo. Cell uptake assays demonstrated that FEMAET and [18F]FEMAET accumulate in prostate cancer (PC-3) and small cell lung cancer cells (NCI-H69), with an energy-dependent mechanism. Small animal PET imaging with NCI-H69 xenograft-bearing mice revealed good tumor visualization comparable to [18F]FET and low brain uptake, indicating negligible transport across the blood–brain barrier. In conclusion, the non-natural cationic amino acid PET probe [18F]FEMAET accumulates in cancer cells in vitro and in vivo with possible involvement of ATB0,+. 相似文献
18.
Shuang Hou Duy Linh Phung Wei-Yu Lin Ming-wei Wang Kan Liu Clifton Kwang-Fu Shen 《Journal of visualized experiments : JoVE》2011,(52)
Biomolecules, including peptides,1-9 proteins,10,11 and antibodies and their engineered fragments,12-14 are gaining importance as both potential therapeutics and molecular imaging agents. Notably, when labeled with positron-emitting radioisotopes (e.g., Cu-64, Ga-68, or F-18), they can be used as probes for targeted imaging of many physiological and pathological processes.15-18 Therefore, significant effort has devoted to the synthesis and exploration of 18F-labeled biomolecules. Although there are elegant examples of the direct 18F-labeling of peptides,19-22 the harsh reaction conditions (i.e., organic solvent, extreme pH, high temperature) associated with direct radiofluorination are usually incompatible with fragile protein samples. To date, therefore, the incorporation of radiolabeled prosthetic groups into biomolecules remains the method of choice.23,24N-Succinimidyl-4-[18F]fluorobenzoate ([18F]SFB),25-37 a Bolton-Hunter type reagent that reacts with the primary amino groups of biomolecules, is a very versatile prosthetic group for the 18F-labeling of a wide spectrum of biological entities, in terms of its evident in vivo stability and high radiolabeling yield. After labeling with [18F]SFB, the resulting [18F]fluorobenzoylated biomolecules could be explored as potential PET tracers for in vivo imaging studies.1 Most [18F]SFB radiosyntheses described in the current literatures require two or even three reactors and multiple purifications by using either solid phase extraction (SPE) or high-performance liquid chromatography (HPLC). Such lengthy processes hamper its routine production and widespread applications in the radiolabeling of biomolecules. Although several module-assisted [18F]SFB syntheses have been reported,29-32, 41-42 they are mainly based on complicated and lengthy procedures using costly commercially-available radiochemistry boxes (Table 1). Therefore, further simplification of the radiosynthesis of [18F]SFB using a low-cost setup would be very beneficial for its adaption to an automated process.Herein, we report a concise preparation of [18F]SFB, based on a simplified one-pot microwave-assisted synthesis (Figure 1). Our approach does not require purification between steps or any aqueous reagents. In addition, microwave irradiation, which has been used in the syntheses of several PET tracers,38-41 can gives higher RCYs and better selectivity than the corresponding thermal reactions or they provide similar yields in shorter reaction times.38 Most importantly, when labeling biomolecules, the time saved could be diverted to subsequent bioconjugation or PET imaging step.28,43 The novelty of our improved [18F]SFB synthesis is two-fold: (1) the anhydrous deprotection strategy requires no purification of intermediate(s) between each step and (2) the microwave-assisted radiochemical transformations enable the rapid, reliable production of [18F]SFB.Download video file.(51M, mov) 相似文献
19.
Geng-Ying Li Daria D. Vaulina Jia-Je Li Olga S. Fedorova Hsin-Ell Wang Ren-Shyan Liu Raisa N. Krasikova Chuan-Lin Chen 《Bioorganic & medicinal chemistry letters》2017,27(15):3460-3463
Given the ever-present demand for improved PET radiotracer in oncology imaging, we have synthesized 2-(3,4-dimethoxyphenyl)-6-(2-[18F]fluoroethoxy)benzothiazole ([18F]FEDBT), a fluorine-18-containing fluoroethylated benzothiazole to explore its utility as a PET imaging tracer. [18F]FEDBT was prepared via kryptofix-mediated nucleophilic substitution of the tosyl group precursor. Fractionated ethanol-based solid-phase (SPE cartridge-based) purification afforded [18F]FEDBT in 60% radiochemical yield (EOB), with radiochemical purity in excess of 98% and the specific activity was 35 GBq/μmol. The radiotracer displayed clearly higher cellular uptake ratio in various breast cancer cell lines MCF7, MDA-MB-468 and MDA-MB-231. However, both biodistribution and microPET studies have showed an higher abdominal accumulation of [18F]FEDMBT and the tumor/muscle ratio of 1.8 was observed in the MDA-MB-231 xenograft tumors mice model. Further the lipophilic improvement is needed for the reducement of hepatobilliary accumulation and to promote the tumor uptake for PET imaging of breast cancer. 相似文献
20.
Bouvet V Wuest M Tam PH Wang M Wuest F 《Bioorganic & medicinal chemistry letters》2012,22(6):2291-2295
A new synthesis of O-(2-[18F]fluoroethyl)-l-tyrosine [18F]FET was developed using a NanoTek® microfluidic synthesis system (Advion BioSciences, Inc.). Optimal reaction conditions were studied through screening different reaction parameters like temperature, flow rate, reaction time, concentration of the labeling precursor, and the applied volume ratio between the labeling precursor and [18F]fluoride. [18F]FET was obtained after HPLC purification with 50% decay-corrected radiochemical yield starting from as little as 40 μg of labeling precursor. Small animal PET studies in EMT-6 tumor bearing mice showed radioactivity accumulation in the tumor (SUV60min 1.21 ± 0.2) resulting in an slightly increasing tumor-to-muscle ratio over time. 相似文献