An integrated strategy for comprehensive characterization of metabolites and metabolic profiles of bufadienolides from Venenum Bufonis in rats

Comprehensive characterization of metabolites and metabolic profiles in plasma has considerable significance in determining the efficacy and safety of traditional Chinese medicine(TCM)in vivo.However,this process is usually hindered by the insufficient characteristic fragments of metabolites,ubiquitous matrix interference,and complicated screening and identification procedures for metabolites.In this study,an effective strategy was established to systematically characterize the metabolites,deduce the metabolic pathways,and describe the metabolic profiles of bufadienolides isolated from Venenum Bufonis in vivo.The strategy was divided into five steps.First,the blank and test plasma samples were injected into an ultra-high performance liquid chromatography/linear trap quadrupole-orbitrap-mass spectrometry(MS)system in the full scan mode continuously five times to screen for valid matrix compounds and metabolites.Second,an extension-mass defect filter model was established to obtain the targeted precursor ions of the list of bufadienolide metabolites,which reduced approximately 39%of the interfering ions.Third,an acquisition model was developed and used to trigger more tandem MS(MS/MS)fragments of precursor ions based on the targeted ion list.The acquisition mode enhanced the acquisition capability by approximately four times than that of the regular data-dependent acquisition mode.Fourth,the acquired data were imported into Compound Discoverer software for identification of metabolites with metabolic network prediction.The main in vivo metabolic pathways of bufadienolides were elucidated.A total of 147 metabolites were characterized,and the main biotransformation reactions of bufadienolides were hydroxylation,dihydroxylation,and isomerization.Finally,the main prototype bufadienolides in plasma at different time points were determined using LC-MS/MS,and the metabolic profiles were clearly identified.This strategy could be widely used to elucidate the metabolic profiles of TCM preparations or Chinese patent medicines in vivo and provide critical data for rational drug use.

Hajek-Rényi-type Inequality and Strong Law of Large Numbers for Some Dependent Sequences

Abstract In this paper, we get the H^jek-R^nyi-type inequalities for a pairwise NQD sequence, an L^T （r 〉 1） mixingale and a linear process, which have the concrete coefficients. In addition, we obtain the strong law of large numbers, strong growth rate and the integrability of supremum for the above sequences, which generalize and improve Corollary 2 for L^T（r 〉 1） mixingale of Hansen.

Thermal and Mechanical Properties of Graphene-Titanium Composites Synthesized by Microwave Sintering

The x wt%graphene-Ti composites（x = 0,0.2,0.3 and 0.4） were obtained using the powder metallurgy method.The X-ray diffraction results demonstrated that the peak intensity of graphene increased monotonically with increasing graphene content.Furthermore,the number of grain boundary and interface between graphene and matrix increased as graphene increased,which led to a sharp rise of thermal resistances.The thermal conductivity and specific heat capacity of composites initially decreased drastically with addition of graphene,but then increased with increasing graphene content from 0.2 to 0.4 wt%.This phenomenon was connected with the graphene content and the characteristics of Ti matrix（pores,grain boundary and interface between graphene and matrix）.The variation of the compressive strength of composites was attributed to the interaction effects of the average grain size of the Ti matrix（d_m） and the volume fraction（V_f） and aspect ratio（A） of graphene.

Current Status and Future Perspective in the Globalization of Traditional Chinese Medicines

Globalization of traditional Chinese medicines started around 1996, which was initiated by the Chinese government. However, substantial progress was only achieved in recent years including the adoption of TCM quality monographs in the western pharmacopoeias(United States Pharmacopoeia and European Pharmacopoeia) and registration in main stream drug regulatory agencies such as US Food and Drug Administration(FDA) and European Medicines Agency(EMA). So far, several TCM herbal quality monographs were adopted by the United States Pharmacopoeia including Chinese Salvia, Ganoderma lucidum and Panax notoginseng, etc. Over 45 TCM quality monographs were recorded in the European Pharmacopoeia with 20 more in progress. After the successful registration of the first TCM product named Diao Xin Xue Kang as traditional medicine via the Medicines Evaluation Board of the Netherlands, several other TCM herbal products are in the registration process in several European member states. So far, there has been still not any TCM product authorized as a drug by the FDA regardless of a few TCM products in phase III or phase II clinical trials. This review summarizes the progress made in the globalization of traditional Chinese medicines in recent years and future issues in this regard.

Chemical Analysis of Xueshuantong Lyophilized Powder by LC-MS Profiling

Objective To elucidate the chemical components of Xueshuantong （XST） Lyophilized Powder and primarily disclose the chemical difference between XST and Panax notoginseng roots. Methods Liquid chromatography coupled with electrospray ionization tandem mass spectrometry （LC-ESI-MSn） was used to profile the saponins in XST and P. notoginseng. Structural elucidation was based on spectral analyses of negative and positive ESI-MS3 data, and the comparison of the retention behaviors. Results The optimized LC-MS profiling approach enabled resolution of major saponins. The negative mode ESI-MS3 fragmentation gave diagnostic information on the nature （neutral loss 162 Da for GIc, 146 Da for Rha, and 132 Da for a pentose） and sequence （priority： terminal 〉 inner） of sugars and sapogenins （m/z 475 for protopanaxatriol; re^z459 for protopanaxadiol）, while the intact glycosyl portion could be characterized by characteristic Zoα, Cnnα＋, and Cnβ＋ （n = 2 or 3） obtained in the positive mode. Ultimately, a total of 30 saponins were characterized from XST. Compared with the roots of P. notoginseng, three malonyl-ginsenosides, ginsenoside Rd, and gyponoside XVII （or its isomer） were almost undetectable, and showed potential significance for their differentiation. Conclusion The established LC-MS profiling approach is powerful for the chemical analysis of P. notoginseng and its preparations such as XST.

The Bahadur Representation for Sample Quantiles Under Dependent Sequence

On the one hand,we investigate the Bahadur representation for sample quantiles underφ-mixing sequence withφ(n)=O(n^-3)and obtain a rate as O(n-3/4 log n),a.s.On the other hand,by relaxing the condition of mixing coefficients to∑∞n=1φ^1/2(n)<∞,a rate O(n^-1/2(log n)^1/2),a.s.,is also obtained.

Ultra-High Performance Liquid Chromatography/Ion Mobility-Quadrupole Time-of-Flight Mass Spectrometry and Database-Driven Automatic Peak Annotation for the Rapid Profiling and Characterization of the Multicomponents from Stephaniae Tetrandrae Radix(Fang-Ji)

Objective:Quality control of traditional Chinese medicine(TCM)begins with the chemical basis elucidation.The root of Stephania tetrandra has long been utilized as an antirheumatic,analgesic,and diuretic TCM,Stephaniae Tetrandrae Radix(STR;Fang-Ji).Powerful analytical strategies enabling its multicomponent characterization is still rare.Methods:A rapid,reliable,and enhanced profiling approach,by ultra-high performance liquid chromatography coupled with ion mobility/quadrupole time-of-flight mass spectrometry(UHPLC/IM-QTOF-MS)and automatic peak annotation facilitated by computational matching of in-house library,was established and utilized to characterize the multicomponents from STR.A knockout strategy was utilized by automated valve switching to overcome the interference of predominant peaks.Results:Good chromatographic separation was achieved within 17 min on a reversed-phase BEH C18 column eluted with acetonitrile/0.1%ammonium hydroxide in water,while data-independent high-definition MS^(E)(HDMS^(E))in positive mode was applied to acquire the MS^(2)data by using a Vion TM IM-QTOF instrument,which in theory,could cover all the profiled precursor ions.An in-house library of 163 compounds was established and incorporated into the UNIFITM platform.By feat of these efforts,we were able to identify or tentatively characterize 76 alkaloids from the methanolic extract of STR,including 14 aporphine-type,four morphine-type,48 bisbenzylisoquinoline-type,seven tetrahydroprotoberberine-type,one protopine-type,one benzylisoquinoline-type,and one other.Four-dimensional information,such as the retention time,collision cross section(CCS),high-accuracy MS1 and MS2 data,for each component was provided.Conclusions:The systematic multicomponent characterization of STR was accomplished with high coverage,high degree of automation,and high reliability.