Gall bladder imaging agent and its preparation method
A novel gall bladder image agent which includes a radio-labelled MAG3-tri-galactosamine, and its preparation method, which includes reacting mercaptoacetyltriglycine (MAG3)-tri-galactosamine, SnF2 and Tc-99m in the presence of a phosphate buffer solution (at pH of from 10.0˜12.0) to obtain Tc-99m-MAG3-tri-galactosamine, when the MAG3-tri-galactosamine is MAG3-DCM-Lys(Gah-GalNAc)3 (where DCM represents a dicarboxymethyl group, and Gah represents a glycine-aminohexyl group), it obtains a labelling yield of at least 90%, and its specific radioactivity is at least 7.0×109 Bq/mg.
1. A method for preparing Tc-99m-MAG 3 -tri-galactosamine, comprising the following steps:
(1) performing glycosidation reaction of acetylated galactose amine and 6-(benzyloxycarbonyl glycine amino) hexanol and performing deprotection of an acetoxy group on the galactose amine using alkali, so as to obtain 6-(benzyloxycarbonyl glycine amino) hexyl galactose amine;
(2) performing hydrogenolysis reaction on the 6-(benzyloxycarbonyl glycine amino) hexyl galactose amine to obtain 6-(glycine amino) hexyl galactose amine;
(3) reacting 6-(glycine amino) hexyl galactose amine and nitrilotriacetic acid protected by benzyloxycarbonyl amine to obtain tri-galactosamine;
(4) performing amide bonding on the obtained tri-galactosamine and mercaptoacetyltriglycine (MAG 3 ) to cause reaction, so as to obtain MAG 3 -tri-galactosamine; and
(5) performing radio-labelling on the obtained MAG 3 -tri-galactosamine and Tc-99m, so as to obtain Tc-99m-MAG 3 -tri-galactosamine.
2. The method for preparing Tc-99m-MAG 3 -tri-galactosamine according to claim 1 , wherein the mercaptoacetyltriglycine (MAG 3 ) used in step (4) uses S-benzoyl thioacetamide triglycine precursor, and performs deprotection of benzoyl before reaction.
3. The method for preparing Tc-99m-MAG 3 -tri-galactosamine according to claim 1 , wherein step (5) is performed with SnHal2 (Hal represents chlorine or fluorine) serving as a reductant and a buffer solution at pH of from 10.0˜12.
4. The method for preparing Tc-99m-MAG 3 -tri-galactosamine according to claim 3 , wherein SnHal 2 is SnF 2 .
5. The method for preparing Tc-99m-MAG 3 -tri-galactosamine according to claim 3 , wherein the buffer solution is a phosphate buffer solution or ammonium acetate (NH4OAc).
6. The method for preparing Tc-99m-MAG 3 -tri-galactosamine according to claim 4 , wherein the buffer solution is a phosphate buffer solution or ammonium acetate (NH4OAc).
7. The method for preparing Tc-99m-MAG 3 -tri-galactosamine according to claim 3 , wherein step (5) is further performed with a stabilizer.
8. The method for preparing Tc-99m-MAG 3 -tri-galactosamine according to claim 4 , wherein step (5) is further performed with a stabilizer.
9. The method for preparing Tc-99m-MAG 3 -tri-galactosamine according to claim 7 , wherein the stabilizer is tartaric acid.
10. The method for preparing Tc-99m-MAG 3 -tri-galactosamine according to claim 1 , wherein the radio-labelling in step (5) comprising reaction lasting for 15 minutes without heating at the room temperature for yielding 97% radio-labelling rate with a specific activity of 3.7×1010 Bq/mg.