Abstract |
Tc-99m Labeled hexamethylenepropyleneamineoxime ([Tc-
99m-HAMPAO) is a famous amine -oxime compound and is
widely used to construct SPECT images of cerebral blood
flow. To investigate the relationship between chemical
structure and radiolabeling in these kind of diamine -
oxime compounds, we synthesized seven compounds by
Schiff's base formation and successive reduction with
sodium borohydride. They wese (RR/SS)-4,8-diaza-
3,6,6,9-tetramethylundecane- 2,10-dione bisoxime (2),
(RR/SS/meso)-4,8-diaza-3,9-dimethy-lundecane-2,10-dione
bisoxime (4), (RR/SS/meso)-4,8-diaza-3,10-
dimethyldodecane-2,11-dione bisoxime (6),
(RR/SS/meso)-4,7-diaza- 3,6,6,8-tetramethyldecane-2,9-
dione bisoxime (8), (RR/SS/meso)-4,7-diaza-5,6-
cyclohexyl-3,8-dime- thyldecane-2,9-dione bisoxime(10),
(RR/SS/meso)-3,4-bis (l-aza-2-methyl-3-oxime-l-butyl)-
benzoic acid (12), and (RR/SS/meso)-2,3-bis(1-aza-2-
methyl-3-oxime-l-butyl) benzophenone (14). Chem- ical
structures of al1 the synthesized compounds were
identified by taking 1H spectrum. Among them, 2 and 4
are propyleneamine oxime(PnAO), 6 is butyleneamine
oxime(BnAO) and 8, 10, 12 and 14 are ethyleneamine
oxime (EnAO), Each compound (0.5 mg) was incubated with
stannous chloride(0.5 g - 8 g), carbonate-bicarbonate
buffer (final concentration = 0.1 M, pH7 - pH 10 ) and
Tc-9mm- pertechenate ( 1 ml). Tc-99m labeling of these
compounds were checked by ITLC (acetone), ITLC (normal
saline), reverse phase TLC (50% acetonitrile) and ITLC
(ethyl acetate). According to the results, EnAO's were
not labeled by Tc-99m in any of above condition. About
11 % of maximum labeling efficiency was obtained with
BnAO. However, 4 (PnAO) was labeled with Tc-99m to 85 %
which is similar to the labeling efficiency of 2
(HMPAO). Hydrophilic impurity (9 %) was the most
significant problem with the labeling of 4, however,
pertechnetate (3 %) and colloid (3 %) were minor
problem. In conclusion, we synthesized seven diamine
bisoxime compounds, Among them, four EnAO compounds
were not labeled by Tc-99m. A BnAO was labeled poor. |