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2-deoxy-2-[18F]-fluoro-3-o-methyl-D-glucose synthesis and animal biodistribution studies
hr. J. Appl. Radim. Isot. Vol. 34. No. I I. pp. 1560-1362, & Pergamon Press Lrd 1983. Printed in Great Britain. 0020-708X:83 S3.00 i 0.00
3-OMG, and [‘8F]fluorine label on carbon-2 as 2-[“FjFDG. Accordingly, we have synthesized 2-deoxy-2-[‘dFJfluoro-3-omethyl-D-ghtcose (_7 ‘“F-3-OMG). by a nucleophilic displacement with [‘*F]fluoride (Fig. 1).
1983
2-Deoxy-2-(1~fluoro-3-o-methyl-DGlucose Synthesis and Animal Biodistribution Studies
Materials
and Methods
18FNeon was bombarded with a 6.5-MeV deuteron beam for 30 min at 50 PA to produce 20-30 mCi of anhydrous ‘*Ffluoride. The~‘sF- produced was trapped from the rapidlycirculated neon (Metal Bellow Corp. pump, ISPSI of I.0 CFM) on a silver-wool plug coated with cesium fluoride. The [‘8F]CsHF, was reacted with 26mg of methyl 4,6-o-benzylidene-3-o-methyl-2-O-triffuoromethanesulfonyl/I-D-mannopyranoside (II) in I mL of freshly-distilled (over calcium hydride) dimethyl formamide, in a reaction vial immersed in an oil bath at 130% for 2.5min. The solvent was evaporated and ether and water added. The ether solution was separated, washed twice, dried using NaSO,, and evaporated under a stream of nitrogen to give methyl 4,6-o-bdnzylidene-3-o-methyl-2-deoxy-~-[”~fluoro-~-Dnlucoovranoside (III) in over 30% yield. The I’*Flglucopyranoside derivative was hydroiyz& with p-toiuene sulfonic acid (SOYJ for 30 min at 120°C. cooled and neutralized (NaOH), evaporated, and taken up in 2 mL of aqueous acetonitrile (0.2 mL H,O in 100 mL CH,CN). The solution was then placed on a column (0.75 x 30 cm) of silica eel and alumina f I: I) and washed with IO mL of acetonit&e followed by IbmL of aqueous acetonitrile solution. The purified 2-‘sF-3-OMG was collected, the solvent was evaporated to dryness (N: stream), saline added, and the solution sterilized by passing through a 0.22 p M millipore filter. The overall yield was IO-ISo/; (200-900 pCi).
S. LEVY, E. LIVNI, D. R. ELMALEH; D. A. VARNUM and G. L. BROWNELL Physics Research Laboratory, Massachusetts General Hospital, Boston, MA 02114, U.S.A. (Received 31 Jununry 1983)
The synthesis of 2-deoxy-2-[18F]fluoro-3-o-methyl-D-glucose is described. The distribution in mice shows an initial uptake of 2% in the brain which decreases to 1.5% at 60 min. Images of “F activity in dogs exhibited uniform distribution of activity in head and chest.
Introduction
3-[“C]Methyl-n-glucose (3-OMG) has been proposed as an agent for measuring glucose transport across the blood brain barrier in man.“+’ This tracer is known to be transported across the cellular membranes and the blood brain barrier like glucose, however, it is not further metabolized. It returns to blood to be equilibrated between blood and tissue. 2-Deoxy-2-[i*F]fluoro-o-glucose (2-FDG)“) and 2-deoxy[“c]-D-ghCOS&’ are currently used for in vivo measurements of glucose metabolism and local cerebral glucose metabolic rates in man. These radiotracers are transported in the same manner as glucose, are phosphorylated and trapped in tissue as 2-DG&PO, with no further metabolism. We were interested in studying the in vivo behavior of an agent that combines functional characteristics of both of these compounds, a methoxy group on carbon-3 such as
Characterization of 2-‘8F-3-OMG
Compound IV was co-chromatographed (TLC, HPLC) with cold samples of 2-F-3-OMG previously proven by the NMR spectra-of their acetates. The two compounds gave the same values [(TLC Rdl.5) (silica gel on alumina, Merck eluant CH$N:H?d (85: i5)) HPLC (ODS Column H,O:CH,CN(5:95) 370 psi) residence time 6.5 min].
CH,OH HO+>OCH OH
HO-
Synthesis
of 3-O-
‘+$$OCH
3
methyl -2-
*
5 steps
deoxy-2-c
CHO3
F-18)-
Fig. I l
Author to whom correspondence
should be addressed. I560
Fluoro-O-glucose
3 I[
( 2-F-3-OMG
1
Technical Table
1561
Note
1. Distribution of “F radioactivity in mouse tissue following i.v. injection of 2-F-EOMG Per cent injected doserg tissue (N = 6)
Blood Brain Liver Spleen Lung Heart Kidney Bone MU& Bladder
5 min
3omin
6Omin
4.02 f 1.08 2.17kO.33 3.87 k 0.48 4.05 f 0.47 5.29 + 0.71 4.23 f 0.32 7.69 k 1.24 1.81 + 0.33 2.67 + 0.05 10.10 + 6.40
2.53 f 0.10 1.51 ro.10 4.12 k 0.37 3.05 k 0.36 2.91 f 0.22 2.17 to.08 4.34 & 0.21 1.21 2 0.33 1.96 k 0.07 22.77 + 16.80
1.77+0.19 1.50 2 0.21 2.94 2 0.76 2.67 + 0.32 2.22 f 0.3 I 1.51 f 0.21 2.83 k 0.41 1.33 * 0.46 1.29 2 0.22 21.84+ 19.72
Table 2. Ratio of per cent injected dose/g of tissue of tumor;blood and tumor/muscle at 5, 30 and 6Omin Time (min) 3: 60
Animal
Tumor/blood 0.78 I.20 I .47
Results and Discossion
Tumor/muscle 0.98 1.40 1.74
experiments
Mice. 2-Deoxy-2-[‘*F]fluoro-3-o-methyl-D-glucosc line (3-5 pCi in 0.1 mL) was injected into
in sa-
groups of six CD-I Fisher Mice (Charles River strain) through a tail vein. At the desired time interval post injection, the mice were killed by cervical fracture. The organs and tissues were excised. rinsed, blotted to remove adhering blood and weighed. They were then counted in a y-ray wellscintillation detector and the count rate corrected for decay. Dogs. Dogs (15-20 kg) were anesthetized with sodium pentobarbital(O.55 cm’/kg) and placed between the camera of the Massachusetts General Hospital positron camera PC-II. 2-‘*F-3-OMG (500-700 yCi in 5-7 mL) was injected through a femoral vein. Sequential 2-D lateral scans were collected and processed after corrections for decay and photon attenuation.
2-t*F-3-GMG was tested for its preliminary biodistribution in mice and imaging in dogs. Table I shows the tissue distribution in mice at 5, 30 and 6Omin for 2-‘*F-3-OMG after i.v. injection. The heart and brain uptake was 4% and 2% at 5 min, respectively, and dropped to 1.5% for each at 6Omin (Fig. 2). The 4% myocardial uptake was decreased by 64% at 60 min (Fig. 2). However, the total activity in brain and heart indicates that there is an initial uptake that equilibrates at 30 min. The brain activity stays constant up to 60 min. The blood activity at 5 min was 4% and decreased slowly to 1.7% at 60 min (Fig. 2). Lung and liver activities exhibited an elimination of 58% and 24x, respectively, at 6Omin compared to their activity at 5min. The activity in the skeletal muscle exhibited an elimination of 51% at 6Omin compared to the activity at 5 min. The uptake of 2-r8F-3-OMG in rats transplanted with RT gliocarcomas was studied at 5,30 and 60 min. Table 2 shows the tumor-to-blood and tumor-to-muscle ratio as a function of time. The tumor-to-blood ratio is 0.78 at 5min and increased to 1.47 at 60 min. whereas the tumor-to-tissue ratio was 0.98 at 5 min and 1.74 at 60 min. The tumor uptake of 2-‘*F-3-OMG is lower than 2-“FDG.‘”
Fig. 3
1562
Technical Note
Images of the dog’s head and chest show a uniform distribution 40min after i.v. injection. In Fig. 3 the sequential curves of 2-“F-3-OMG shows the fast clearance of activity of the liver and heart and the slow clearance of the activity in the brain. However, the activity in the skeletal muscle slowly increased for 15 mm post injection and remained essentially unchanged for up to 54min. Comparison of our data with Klosters er al.‘” shows a similar behavior to 3-OMG. The activity in blood, brain and heart is high for the first l5min. However, this tissue activity with 2-‘*F-3-OMG at 30 and 60min is higher, exhibiting a slower washout from these 3 tissues compared to 3-OMG and not as high as t-FDG. In conclusion, the behavior of 2-F-3-OMG is different from that of the 2-FDG. However, it may have potential as a tracer for measuring glucose transport across the blood brain barrier. Acknowledgements-We acknowledge the technical assistance of the cyclotron operators, W. Bucelewicz and L. Beagle. This work was supported by DOE-AC0276EVO41 I5 and by NIH Cancer Grant 2 ROI CA26371-03.
References I. Vyska K., Freundlieb C.. Hock A.. Becker V., Feinendegen L. E., Kloster G., Stocklin G.. Traup H. and Heiss W. D. J. Cereb. Blood Flow Merub. 1 (Suppl. I), S42 (1981). 2 Kloster G., Miiller-Platz C. and Lanfer P. 1. Labelled Camp. Rudiopharm. XVIII, 855-863 (1981). Vyska K., Freundlieb C., Hock A., Becker V., Feinendegen L. E., Schuier F. J., Thal H. U., Kloster G., Stocklin G. and Heiss W. D. J. Nucl. Med. 23, 13 (1982). Giedde A. and Siemkowicz E. J. Cereb. Blood Flow tietab. 1 (Suppl. I), S74 (1981). Greenbera J. H.. Reivich M., Alavi A., Hand P., Rosenq& A., Rintelmann W., Stein A.. Tusa R., Dann R., Christman D., Fowler J.. MacGregor B. and Wolf A. Science 212, 678 (1981). 6. Goodman M. M., Kearfott K. H., Ehualeh D. R., Alpert N. M. and Brownell G. L. In Radiopharmaceuticals Structure Acthity Relationships (Ed. Spencer R. P.), pp. 801-833. (Grune 8~ Stratton, New York, 198I).
3-OMG, and [‘8F]fluorine label on carbon-2 as 2-[“FjFDG. Accordingly, we have synthesized 2-deoxy-2-[‘dFJfluoro-3-omethyl-D-ghtcose (_7 ‘“F-3-OMG). by a nucleophilic displacement with [‘*F]fluoride (Fig. 1).
1983
2-Deoxy-2-(1~fluoro-3-o-methyl-DGlucose Synthesis and Animal Biodistribution Studies
Materials
and Methods
18FNeon was bombarded with a 6.5-MeV deuteron beam for 30 min at 50 PA to produce 20-30 mCi of anhydrous ‘*Ffluoride. The~‘sF- produced was trapped from the rapidlycirculated neon (Metal Bellow Corp. pump, ISPSI of I.0 CFM) on a silver-wool plug coated with cesium fluoride. The [‘8F]CsHF, was reacted with 26mg of methyl 4,6-o-benzylidene-3-o-methyl-2-O-triffuoromethanesulfonyl/I-D-mannopyranoside (II) in I mL of freshly-distilled (over calcium hydride) dimethyl formamide, in a reaction vial immersed in an oil bath at 130% for 2.5min. The solvent was evaporated and ether and water added. The ether solution was separated, washed twice, dried using NaSO,, and evaporated under a stream of nitrogen to give methyl 4,6-o-bdnzylidene-3-o-methyl-2-deoxy-~-[”~fluoro-~-Dnlucoovranoside (III) in over 30% yield. The I’*Flglucopyranoside derivative was hydroiyz& with p-toiuene sulfonic acid (SOYJ for 30 min at 120°C. cooled and neutralized (NaOH), evaporated, and taken up in 2 mL of aqueous acetonitrile (0.2 mL H,O in 100 mL CH,CN). The solution was then placed on a column (0.75 x 30 cm) of silica eel and alumina f I: I) and washed with IO mL of acetonit&e followed by IbmL of aqueous acetonitrile solution. The purified 2-‘sF-3-OMG was collected, the solvent was evaporated to dryness (N: stream), saline added, and the solution sterilized by passing through a 0.22 p M millipore filter. The overall yield was IO-ISo/; (200-900 pCi).
S. LEVY, E. LIVNI, D. R. ELMALEH; D. A. VARNUM and G. L. BROWNELL Physics Research Laboratory, Massachusetts General Hospital, Boston, MA 02114, U.S.A. (Received 31 Jununry 1983)
The synthesis of 2-deoxy-2-[18F]fluoro-3-o-methyl-D-glucose is described. The distribution in mice shows an initial uptake of 2% in the brain which decreases to 1.5% at 60 min. Images of “F activity in dogs exhibited uniform distribution of activity in head and chest.
Introduction
3-[“C]Methyl-n-glucose (3-OMG) has been proposed as an agent for measuring glucose transport across the blood brain barrier in man.“+’ This tracer is known to be transported across the cellular membranes and the blood brain barrier like glucose, however, it is not further metabolized. It returns to blood to be equilibrated between blood and tissue. 2-Deoxy-2-[i*F]fluoro-o-glucose (2-FDG)“) and 2-deoxy[“c]-D-ghCOS&’ are currently used for in vivo measurements of glucose metabolism and local cerebral glucose metabolic rates in man. These radiotracers are transported in the same manner as glucose, are phosphorylated and trapped in tissue as 2-DG&PO, with no further metabolism. We were interested in studying the in vivo behavior of an agent that combines functional characteristics of both of these compounds, a methoxy group on carbon-3 such as
Characterization of 2-‘8F-3-OMG
Compound IV was co-chromatographed (TLC, HPLC) with cold samples of 2-F-3-OMG previously proven by the NMR spectra-of their acetates. The two compounds gave the same values [(TLC Rdl.5) (silica gel on alumina, Merck eluant CH$N:H?d (85: i5)) HPLC (ODS Column H,O:CH,CN(5:95) 370 psi) residence time 6.5 min].
CH,OH HO+>OCH OH
HO-
Synthesis
of 3-O-
‘+$$OCH
3
methyl -2-
*
5 steps
deoxy-2-c
CHO3
F-18)-
Fig. I l
Author to whom correspondence
should be addressed. I560
Fluoro-O-glucose
3 I[
( 2-F-3-OMG
1
Technical Table
1561
Note
1. Distribution of “F radioactivity in mouse tissue following i.v. injection of 2-F-EOMG Per cent injected doserg tissue (N = 6)
Blood Brain Liver Spleen Lung Heart Kidney Bone MU& Bladder
5 min
3omin
6Omin
4.02 f 1.08 2.17kO.33 3.87 k 0.48 4.05 f 0.47 5.29 + 0.71 4.23 f 0.32 7.69 k 1.24 1.81 + 0.33 2.67 + 0.05 10.10 + 6.40
2.53 f 0.10 1.51 ro.10 4.12 k 0.37 3.05 k 0.36 2.91 f 0.22 2.17 to.08 4.34 & 0.21 1.21 2 0.33 1.96 k 0.07 22.77 + 16.80
1.77+0.19 1.50 2 0.21 2.94 2 0.76 2.67 + 0.32 2.22 f 0.3 I 1.51 f 0.21 2.83 k 0.41 1.33 * 0.46 1.29 2 0.22 21.84+ 19.72
Table 2. Ratio of per cent injected dose/g of tissue of tumor;blood and tumor/muscle at 5, 30 and 6Omin Time (min) 3: 60
Animal
Tumor/blood 0.78 I.20 I .47
Results and Discossion
Tumor/muscle 0.98 1.40 1.74
experiments
Mice. 2-Deoxy-2-[‘*F]fluoro-3-o-methyl-D-glucosc line (3-5 pCi in 0.1 mL) was injected into
in sa-
groups of six CD-I Fisher Mice (Charles River strain) through a tail vein. At the desired time interval post injection, the mice were killed by cervical fracture. The organs and tissues were excised. rinsed, blotted to remove adhering blood and weighed. They were then counted in a y-ray wellscintillation detector and the count rate corrected for decay. Dogs. Dogs (15-20 kg) were anesthetized with sodium pentobarbital(O.55 cm’/kg) and placed between the camera of the Massachusetts General Hospital positron camera PC-II. 2-‘*F-3-OMG (500-700 yCi in 5-7 mL) was injected through a femoral vein. Sequential 2-D lateral scans were collected and processed after corrections for decay and photon attenuation.
2-t*F-3-GMG was tested for its preliminary biodistribution in mice and imaging in dogs. Table I shows the tissue distribution in mice at 5, 30 and 6Omin for 2-‘*F-3-OMG after i.v. injection. The heart and brain uptake was 4% and 2% at 5 min, respectively, and dropped to 1.5% for each at 6Omin (Fig. 2). The 4% myocardial uptake was decreased by 64% at 60 min (Fig. 2). However, the total activity in brain and heart indicates that there is an initial uptake that equilibrates at 30 min. The brain activity stays constant up to 60 min. The blood activity at 5 min was 4% and decreased slowly to 1.7% at 60 min (Fig. 2). Lung and liver activities exhibited an elimination of 58% and 24x, respectively, at 6Omin compared to their activity at 5min. The activity in the skeletal muscle exhibited an elimination of 51% at 6Omin compared to the activity at 5 min. The uptake of 2-r8F-3-OMG in rats transplanted with RT gliocarcomas was studied at 5,30 and 60 min. Table 2 shows the tumor-to-blood and tumor-to-muscle ratio as a function of time. The tumor-to-blood ratio is 0.78 at 5min and increased to 1.47 at 60 min. whereas the tumor-to-tissue ratio was 0.98 at 5 min and 1.74 at 60 min. The tumor uptake of 2-‘*F-3-OMG is lower than 2-“FDG.‘”
Fig. 3
1562
Technical Note
Images of the dog’s head and chest show a uniform distribution 40min after i.v. injection. In Fig. 3 the sequential curves of 2-“F-3-OMG shows the fast clearance of activity of the liver and heart and the slow clearance of the activity in the brain. However, the activity in the skeletal muscle slowly increased for 15 mm post injection and remained essentially unchanged for up to 54min. Comparison of our data with Klosters er al.‘” shows a similar behavior to 3-OMG. The activity in blood, brain and heart is high for the first l5min. However, this tissue activity with 2-‘*F-3-OMG at 30 and 60min is higher, exhibiting a slower washout from these 3 tissues compared to 3-OMG and not as high as t-FDG. In conclusion, the behavior of 2-F-3-OMG is different from that of the 2-FDG. However, it may have potential as a tracer for measuring glucose transport across the blood brain barrier. Acknowledgements-We acknowledge the technical assistance of the cyclotron operators, W. Bucelewicz and L. Beagle. This work was supported by DOE-AC0276EVO41 I5 and by NIH Cancer Grant 2 ROI CA26371-03.
References I. Vyska K., Freundlieb C.. Hock A.. Becker V., Feinendegen L. E., Kloster G., Stocklin G.. Traup H. and Heiss W. D. J. Cereb. Blood Flow Merub. 1 (Suppl. I), S42 (1981). 2 Kloster G., Miiller-Platz C. and Lanfer P. 1. Labelled Camp. Rudiopharm. XVIII, 855-863 (1981). Vyska K., Freundlieb C., Hock A., Becker V., Feinendegen L. E., Schuier F. J., Thal H. U., Kloster G., Stocklin G. and Heiss W. D. J. Nucl. Med. 23, 13 (1982). Giedde A. and Siemkowicz E. J. Cereb. Blood Flow tietab. 1 (Suppl. I), S74 (1981). Greenbera J. H.. Reivich M., Alavi A., Hand P., Rosenq& A., Rintelmann W., Stein A.. Tusa R., Dann R., Christman D., Fowler J.. MacGregor B. and Wolf A. Science 212, 678 (1981). 6. Goodman M. M., Kearfott K. H., Ehualeh D. R., Alpert N. M. and Brownell G. L. In Radiopharmaceuticals Structure Acthity Relationships (Ed. Spencer R. P.), pp. 801-833. (Grune 8~ Stratton, New York, 198I).