To examine the metabolism of genipin-1-β-d-gentiobioside (GG), its distribution and biotransformation in vivo and in vitro were investigated. Urine, plasma, feces, and various organs were collected after oral administration of GG to normal rats and pseudo-germ-free rats to evaluate GG metabolism in vivo. GG was incubated with intestinal flora and primary hepatocytes in vitro to investigate microbial and hepatic metabolism. Using HPLC-Q-TOF-LC/MS, 11 metabolites of GG were absolutely or tentatively identified in terms possible elemental compositions, retention times, and characteristics of fragmentation patterns corresponding to eight biotransformations: deglycosylation, hydroxylation, sulfate conjugation, glucuronidation, hydrogenation, demethylation, glycosylation, and dehydration. Fewer metabolites were detected in pseudo-germ-free rats than in conventional rats. Moreover, geniposide and genipin were generated by the deglycoslation of intestinal bacteria. Geniposidic acid was detected in rat primary-hepatocyte incubation. This study first explores the metabolism of GG in vivo and in vitro. The results can aid the elucidation of PK profiles and clinical usage of gardenia fruit.

Timosaponin B-III (TB-III) is a steroidal saponin isolated from the rhizome of Anemarrhenae asphodeloides (Liliaceae). The biotransformation of TB-III by β-glucosidase was investigated. Three biotransformation products were isolated and their structures were identified as timosaponin B-III-a (M1), (20R,25S)-5β-spirostane-3β-ol-3-O-β-D-glucopyranosyl-(1 → 2)-β-D-galacopyanoside (M2) and timosaponin AIII (M3). Then the four compounds were evaluated for their anti-depressive activity in mice by the open field test, tail suspension test and forced swimming test. As a result, TB-III, M1 and M3 exhibited modest anti-depressive activity. Structure-activity relationships were investigated and the preliminary conclusions are summarised as follows: the glycosyl at C-3 and C-26 can increase the activity, the double bond between C-20 and C-22 might be important for the anti-depressive activity, the R-configuration at C-22 and S-configuration at C-20 are necessary for its anti-depressive activity.

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Paederia scandens (Lour.) Merri. (Jishiteng in Chinese) is a Chinese traditional medicine widely used in treating various diseases. However, its active components have remained unknown. In the present study, a rapid and sensitive method by high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-MSn) techniques was employed to investigate the absorbed constituents in rats after oral administration of Paederia scandens decoction. By comparing their MS data with those of authentic compounds and published data, a total of six compounds (paederosid, 1; paederosidic acid, 2; paederosidic acid methyl ester, 3; 6-hydroxy geniposide, 4; asperuloside, 5; and deacetyl asperuloside, 6) were identified in the P. scandens decoction samples. In addition, a total of seven compounds, including three iridoid glucosides and four of their metabolites, were identified in rat urine samples after administration. In addition, six compounds, including four iridoid glucosides and two of their metabolites, were identified in rat serum samples after administration. Our results significantly narrow the range of potentially active compounds in P. scandens decoction, and build a solid foundation for future research on its mechanism.

Seven steroidal saponins (1-7) and two xanthones (8, 9) were isolated from the rhizomes of Anemarrhena asphodeloides. Then in order to discover more analogues, which may possess good biological activity, the structural modifications of 2 and 9 were performed by acid hydrolysis and acetylation. Consequently, one novel steroidal saponin (2d, timosaponin BII-d), three compounds (2c, 2e and 2f) which were also the new products prepared by the diluted acid hydrolysis of 3 by our group previously, and four known compounds (2a, 2b, 9a and 9b) were obtained. The structures were elucidated by analyses of NMR and MS data. All the compounds were evaluated for their cytotoxicities against BEL-7402, HT-29, HeLa and MDA-MB-468 cell lines in vitro by Sulforhodamine protein coloration method. Compounds 1, 2, 2b, 4-6, 9a and 9b showed certain anti-proliferative activities against the four cell lines, in which compounds 2, 4 and 9b exhibited especially more potent activities. The structure-activity relationships of these compounds were simply discussed.