Pharmaceutical Chemistry Journal
Vol. 36, No. 8, 2002
3
H -AMYXIN SYNTHESIS AND ISOLATION FROM BIOLOGICAL
2
SUBSTRATES
V. A. Karpinchik,1 G. V. Mal’tsev,1 and S. K. Sumrii1
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 36, No. 8, pp. 47 – 49, August, 2002.
Original article submitted April 15, 2002.
2-N,N-Diethylamino-[1-3H]-ethylchloride hydrochlo-
ride (II). To a solution of 0.3 g (2.6 mmole) 2-N,N¢-diethyl-
amino-[1-3H]-ethan-1-ol (I) in 30 ml of anhydrous dichloro-
methane was added 0.5 g (4.2 mmole) of freshly distilled
thionyl chloride and the reaction mass was stirred for 10 h at
25°C. Then the dichloromethane was evaporated to dryness
at a reduced pressure (water-jet pump). The residue was dis-
solved in 1 ml of water and used for the synthesis of
2,7-bis-(2-N,N-diethylamino-[1-3H]-ethoxy)fluoren-9-one
(III).
Amyxin is known to possess a broad spectrum of phar-
macological activity, including antiviral, antiinflammatory,
antimicrobial, and radioprotector properties [1 – 3]. The pur-
3
pose of our work was to synthesize labeled H-amyxin, de-
termine the characteristics of extraction of the radioactive
material from biological substrates in both in vitro and in
vivo model experiments, and study the process of amyxin
elimination from the rat upon a single administration. The
target 3H2-amyxin was obtained from tritium-labeled
aminoethanol by the following scheme:
C2H5I/K2CO3/CH3CN
H2N CH2 C3H2 OH
2,7-bis-(2-N,N-Diethylamino-[1-3H]-ethoxy)fluoren-9
3
-one dihydrochloride (IV), H2-amyxin. To a mixture of
(C2H5)2N CH2 C3H2 OH
I
0.151 g (0.7 mmole) 2,7-dioxyfluoren-9-one, 10 ml of a 50%
sodium hydroxide solution, 0.03 g (0.7 mmole) tetrabutyl-
ammonium iodide (TBAI), and 30 ml toluene was added an
aqueous solution of 2-N,N-diethylamino-[1-3H]-ethyl-
chloride hydrochloride (II) and the mixture was stirred for
6 h at 80°C. Upon cooling, the toluene layer was separated
and evaporated to dryness. The residue was dissolved in 3 ml
of acetone. To this solution was added a solution of hydrogen
chloride in anhydrous 2-propanol until an acid reaction
(pH 3). The precipitate was separated by filtration, washed
with acetone, and dried to obtain 0.241 g (71.3%) of com-
pound IV.
SOCl2/CHCl3
(C2H5)2N CH2 C3H2 OH
I
(C2H5)2N CH2 C3H2 Cl
· HCl
II
EXPERIMENTAL CHEMICAL PART
2-N,N-Diethylamino-[1-3H]-ethan-1-ol (I). To a mix-
ture of 5 g of freshly calcined potassium carbonate and 70 ml
of acetonitrile was added 2 g (32.7 mmole) of monoethanola-
mine and 2-amino-[1-3H]-ethanol hydrochloride with a total
activity of 1 mCi. The reaction mass was stirred and heated
to boiling, after which 11.2 g (71.9 mmole) of ethyl iodide
was gradually (over 4 h) added and boiling with stirring was
continued for another 6 h. After cooling, the reaction mass
was filtered and the residue on filter was washed with ace-
tone (2 ´ 30 ml). The combined filtrate was evaporated to
dryness at a reduced pressure (water-jet pump). The residue
was extracted with diethyl ether (5 ´ 20 ml). The ether ex-
tract was evaporated at a reduced pressure to obtain 300 mg
(7.8%) of compound I.
Model experiments aimed at optimization of the extrac-
tion process in vitro were performed with rat liver homoge-
nates. To 1 ml of a homogenate was added [3H]-amyxin to a
concentration of 0.04 mg/ml. Then the mixture was repeat-
edly extracted with chloroform (6 ´ 5 ml) and the total con-
tent of radioactive material in the organic (chloroform) and
residual (aqueous) phases was determined using a Tri-Carb
2700 TR liquid scintillation counter (Canberra-Packard Co.).
The experiments in vivo were performed on a group of
Wistar male rats weighing 200 – 250 g. The animals were
kept in metabolic boxes with free access to food and water.
Samples of feces and urine were taken once a day. The con-
tent of [3H]-amyxin and its metabolites in the samples was
determined as described in [4]. TLC radiochromatography
1
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448
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