Tz-Hong Lin

Synthesis and preliminary scintigraphic evaluation of in vivo distribution of 11C-hydroxyurea/isohydroxyurea and 11C-Cyanate

H11CN, produced directly from proton bombardment of 99% N2−1% H2 [14N(p, α)11C], was oxidized by KMnO4 to 11C-cyanate which was added to hydroxylamine at −5 to 0°C to yield a mixture of hydroxyurea and isohydroxyurea. Scintigraphic evaluation of in vivo distribution in a dog following administration of KO11CN showed diffuse whole-body distribution, apparently including brain, with greater activity seen in regions of the heart, liver, and kidneys. Similar evaluation of a dog given 11C-hydroxyurea/isohydroxyurea showed early localization of activity in the region of the heart which appeared to be due to activity in the myocardium. However, tissue activity measured in rats after administration of this material failed to demonstrate concentration in the myocardium.

Synthesis and preliminary scintigraphic evaluation of in vivo distribution of 11C-lactic acid and 11C-lactonitrile

Abstract H 11 CN produced directly by 22 meV proton bombardment of 99% N 2 -1% H 2 [ 14 N(p,α) 11 C] was trapped in an aqueous solution of NaCN. A description is given how in 68 min 11 C-lactonitrile (radiochemical yield 60%) and in 119 min 11 C-lactic acid (radiochemical yield 53.5%) were obtained. Scintigraphic images following the i.v. administration to a dog showed initial accumulation of activity in the regions of the heart, liver and kidneys. However, by 7 min postadministration, only the liver showed some concentration of activity with the remaining activity diffusely distributed throughout the body.

RELATIONSHIP OF MOLECULAR STRUCTURE TO IN VIVO SCINTIGRAPHIC DISTRIBUTION OF CARBON-11-LABELED COMPOUNDS. 4. CARBON-11-LABELED MANDELONITRILES, MANDELIC ACIDS, AND THEIR ESTERS

11C-Labeled HCN was collected in water containing carrier KCN following bombardment of 99% N2-1% H2 with 22 MeV protons. 11C-Labeled mandelonitrile and p-methoxy-, p-hydroxy-, and 3,4-dihydroxymandelonitrile were synthesized from K11CN and the corresponding benzaldehyde. The initial distribution of 11C activity of these nitriles in dogs was primarily in the region of the heart, liver, and kidneys followed by rapid redistribution to the parotids and stomach with [11C]hydroxymandelonitriles. 11C-Labeled mandelic acid and m-methyl-, o-chloro-, and p-chloromandelic acid were synthesized from the corresponding [11C]mandelonitrile. Serial scintigraphy of 11C activity of these mandelic acids in dogs showed progressive renal excretion with accumulation of activity in the bladder. 11C-Labeled ethyl and benzyl mandelate were synthesized from [11CA]mandelic acid. These esters showed initial accumulation of activity in the lungs with eventual excretion by the kidneys.