[Isolation and identification of a major metabolite of SFZ-47 in the rabbit urine].
OBJECTIVE
To isolate and identify a glucuronide metabolite of SFZ-47 [3H-1,2-dihydro-2-(4-methyl-phenylamino)methyl-1-pyrrolizinone], which is difficult to synthesize because it undergoes hydrolysis and intramolecular acyl migration at physiological pH, in rabbit urine.


METHODS
Two rabbits were ig 200 mg doses of SFZ-47. Urine was collected for 24 h, adjusted to pH 4.0 with acetic acid and lyophilized. The residues were reconstituted in 25 mL methanol and centrifuged at 5,000 r.min-1 for 10 min. The supernatant was filtered (0.45 micron) and then isolated with semi-preparative reversed phase HPLC. The eluent collected from individual peaks was evaporated by rotary evaporation and freeze-drying. Compounds were then identified with electrospray ion trap mass spectrometry and 1HNMR spectroscopy.


RESULTS
The 1HNMR and ESI-MSn results indicate that the metabolite is the 1-O-acyl beta-D-glucuronide conjugate of 4-(3H-1,2-dihydro-1-pyrrolizinone-2-methylamino) benzoic acid.


CONCLUSIONS
This method was shown to be rapid and simple and gave excellent resolution from endogenous constituents in urine, and it is suitable for preparation of the glucuronide metabolites of SFZ-47 and its analogues.
Dong
Qing-guang
QG
Laboratory of Drug Metabolism, College of Life Science, Jilin University, Changchun 130023, China. gujingkai@163.net
Gu
Jing-kai
JK
Zhong
Da-fang
DF
Chu
Da-feng
DF
Sun
Lu
L
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000378:metabolism* / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D008297:Male; D015394:Molecular Structure; D011758:Pyrroles / Q000737:chemistry / Q000378:metabolism* / Q000652:urine; D011817:Rabbits; D021241:Spectrometry, Mass, Electrospray Ionization
C460139:3H-1,2-dihydro-2-(4-methylphenylamino)methyl-1-pyrrolizinone; D000894:Anti-Inflammatory Agents, Non-Steroidal; D011758:Pyrroles