[Intestinal bacteria metabolism of TSDP and characterization of metabolites in rats].
OBJECTIVE
To study the rat intestinal bacteria metabolism of total saponins of Dioscorea pathaica (TSDP) in vitro, and characterize the metabolites in serum and urine of rats after oral administration of TSDP 900 mg.kg-1.


METHODS
TSDP metabolites were detected with thin-layer chromatography (TLC) and combination of electrospray ionization mass spectrometry (ESI-MS) and sequential tandem mass spectrometry (MSn).


RESULTS
In vitro, TSDP was decomposed easily by rat intestinal bacteria, and metabolites DP-1, DP-2, DP-4, DP-5 and diosgenin (Dio) were observed with prolongation of incubation time by ESI-MS2. In vivo, in the full-scan positive mass spectrum of the rat urine sample, the ion peak at m/z 415 (M-H) and its characteristic fragmentations at m/z 397 and m/z 271 in the MS/MS spectrum were identified with that of metabolite Dio, therefore metabolite Dio was deduced to exist in the rat urine, and metablite Dio was allso detected in the rat serum sample.


CONCLUSIONS
TSDP is decomposed easily by rat intestinal bacteria and metabolite diosgenin is absorbed into blood after oral administration of TSDP.
Ma
Hai-ying
HY
Institute of Biological Engineering, Norman Bethune University of Medical Sciences, Changchun 130021, Jilin, China.
Zhou
Qiu-li
QL
Wang
Ji-yan
JY
Wang
Ben-xiang
BX
D000818:Animals; D001711:Biotransformation; D027742:Dioscorea / Q000737:chemistry*; D004144:Diosgenin / Q000378:metabolism; D006089:Gram-Negative Anaerobic Bacteria / Q000378:metabolism*; D007422:Intestines / Q000382:microbiology*; D008297:Male; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D012503:Saponins / Q000302:isolation & purification / Q000493:pharmacokinetics*; D021241:Spectrometry, Mass, Electrospray Ionization
D012503:Saponins; D004144:Diosgenin