| Most bryophytes contain oil bodies which are mainly composed of mono-sesqui-and diterpenoids and/or lipophilic aromatic compounds. Lots of compounds from bryophytes exhibit interesting organoleptic, pharmacological and other biological activities. Thus, the chemistry of bryophytes has been subject to intensive investigations over the last decades.In recent years, as the incidence of tumor affection and HIV infection are on the rise, the genenral use of such therapeutical techniques as organ transplantation, catheterization and endoscopy are more common, and the administration of broad-spctrum antibiotics, immunosuppressive agents and steroid hormones are more extensive, fungal infections especially deep mycosis tend to arise. Yet due to drug resistance and side effects or toxicity, antifungal agents now used in clinic can not reach the expected effects. Intense efforts in antifungal drug discovery are desperately needed to develop more promising and effective antifungal agents in today's medical fields.In the present paper, the rapid screening for bisbibenzyls and ent-kaurane diterpenoids from brytophytes by using LC-MS/MS and GC-MS were developed to increase the rate of discovery of truly novel natural product. One of the bisbibenzyls named Riccardin D, with antifungal bioactivity, was researched further on the pharmacokinetic properties by means of LC-MS/MS. It should be helpful for acquiring a deep understanding of the pharmacokinetics of Riccardin D in vivo as well as rationalizing the future drug design.1. Rapid screening of bisbibenzyls and ent-kaurane diterpenoids from bryophytes In the present paper, we report a systematical investigation of the fragmentation behaviors of the bisbibenzyls by TQ-MS/MS in both positive and negative ion mode. The mass profile of bisbibenzyls in positive ion mode by using LTQ-Obitrap was also evaluated. On the other hand, the mass spectrometric behavior of the ent-kaurane diterpenoids was also investigated in detail by GC-MS. Based on the fragmentation rules of the bisbibenzyls and ent-kaurane diterpenoids, the rapid screening of bisbibenzyls from 14 bryophytes and ent-kanrane diterpenoids from Jungermannia atrobrunnea were performed. The structures of several unknown compounds were proposed. The results of the analysis provide useful information to further research of the bryophytes. The detailed mass spectrometric analysis of bisbibenzyls and ent-kaurane diterpenoids will aid future work in rapidly screening new compounds in bryophytes as well as other plants which are abundant in the bisbibenzyl and ent-kaurane diterpenoids.2. The pharmacokinetics study of Riccardin DThe metabolic profiles of Riccardin D in rats were investigated and the metabolites were identified by LC/MS together with the elemental composition. Two metabolites were found and proved as glucuronides of Riccardin D. An LC MS/MS method was developed and validated for the determination of Riccardin D in rat plasma. Following a single oral and intravenous administration of Riccardin D to rats, free (unconjugated) and total (free plus conjugated) of Riccardin D were determined by measuring the rat plasma before and after enzymatic hydrolysis, and the pharmacokinetic parameters were obtained. The Peak concentrations of 313.5±147.3 and 2788.7±366.8 ng/mL were achieved at 0.33 and 0.5±0.2 h for Riccardin D and total Riccardin D, respectively. The absolute bioavailability calculated with free Riccardin D was 10.6 %, which was 29.9 % when calculated with total Riccardin D. It was showed that Riccardin D has a relatively lower bioavailability. although it was well and quickly absorbed in rats. The main reason may be that Riccardin D suffered a strong first-Pass metabolism to produce conjugated metabolite.
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