Objective To develop a sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of forsklin in rat plasma.Methods After extraction with methyl tert-butyl ether,chromatographic separation was performed on a C18 column with the mobile phase consisting of water ( 0.1％ formic acid)-acetonitrile in a gradient elution mode.A tandem mass spectrometer equipped with electrospray ionization (ESI) source was used as detector in the positive ion mode.Quantification was performed using multiple reaction monitoring (MRM) with the precursor product combination ions of m/z 411→375.3 and 285→193 for forsklin and diazepam.Results Good linearity was obtained in the 0.5-1000 ng/ml range for the analyte and the analytical method was validated in terms of specificity,precision,accuracy,recovery,stability and matrix effect.These assays gave RSD values always lower than 14.4％ and RE values between -3.5 ％ and 3.8％.In addition,the specificity,extraction recovery,stability and matrix effect were satisfactory.Conclusion Due to its high sensitivity,specificity and simplicity,the method could be used for pharmacokinetic studies of forsklin.

Objective To develop a HPLC-MS/MS method for the determination of aconitine and study thein vitro metabolic stability of aconitine in dog tissue homogenates.Methods The chromatographic separation was performed on a C18 column.The mobile phase consisted of acetonitrile and water with 0.2％ formic acid and 5 mmol/L ammonium acetate.A triple quadrupole tandem mass spectrometer equipped with an electrospray ionization interface source was used for the quantitative determination in the positive selective reaction monitor mode.Aconitine was incubated with dog tissue homogenates and samples were withdrawn at different time points and precipitated by acetonitrile with internal standards citalopram.Results Aconitine showed good linear relationship over the range from 5 to 500 ng/ml.The recoveries of aconitine were between 85.73％ and 92.12％ at three QC concentration levels.The intra- and inter-day precisions were 5.32％ - 8.95％ and 5.45％ - 8.86％,respectively.After incubation,about 20％ of aconitine were cleared in the liver and small intestine,and t1/2 were 460.6 and 521.3 min,respectively.But none was metabolized in the stomach and kidney.Conclusion These results demonstrated that aconitine was mainly metabolized in the liver and small intestine at a slow rate.

Objective To study the content difference of avicularin,quercitrin and quercetin in Herba Taxilli from different host plants. Methods The contents of avicularin,quercitrin and quercetin in Herba Taxilli were determined by RP-HPLC and the samples were prepared by ultrasonic extraction with methanol. The analytical column was UltImate XB-C18(250 mm×4.6 mm,5μm), the mobile phase was acetonitrile-methanol-0.1%phosphate with gradient elution,at a flow rate of 1.0 ml/min. The column tempera-ture was set at 25℃,the detection wavelength was 254 nm for avicularin and quercitrin,and 365 nm for quercetin. Results The lin-ear range of the above three ingrediets were 0.0992-1.9840(r=0.9999),0.2254-4.4580(r=0.9999)and 0.1258-2.5160μg(r=0.9997) and the average recovery rates(n=5)were 98.39%,97.08%and 98.159%,respectively. Their contents from different host plants were 0.0000-0.0398,0.3977-0.7639 and 0.0068-0.0231 mg/g in branches and 0.0167-0.1704,1.8626-11.0041,and 0.0185-0.1841 mg/g in leaves. Conclusion The method is accurate,simple and reproducible,and can be used for the quality control of Herba Taxilli.

Objective To investigate the antidiabetic effect of Acanthopanax senticosus extracts based on metabonomics by UPLC-MS/MS and to explore its mechanisms. Methods The type 2 diabetes mellitus(T2DM)mouse model was established by inject-ing streptozocin(streptozotocin,STZ)in combination with alloxan. The effect of A. senticosus extracts on the fasting blood glucose of mice was observed. Multivariate statistical analysis was employed to analyze serum metabolites. The differential metabolites were iden-tified by online and self-built databases. MetPA Was employed to analyze the corresponding metabolic pathways. Results The T2DM model was established successfully. Compared with the model group,the fasting blood glucose of mice in the A. senticosus extracts groups decreased significantly. Compared with the normal control group,the level of phenylalanine,LysoPC(16:0,18:0),tyrosine, serine,urea andβ-hydroxybutyric acid inecreased,while the level of alanine,glutamine,leucine,valine and lactic acid decreased significantly in the model group. Pathway enrichment displayed that these metabolites were mainly involved in five metabolic pathways. The above-mentioned metabolites reversed to the normal level in varying degrees after administration of A. senticosus glycosides or poly-saccharoses extracts. Conclusion The extracts of A. senticosus display a significant hypoglycemic effect which might be achieved by regulation of amino acid,energy and lipid metabolism.

Objective To synthesize four related substances:1b,1c,1d,and 1e according to the synthetic process of aprepi-tant and its quality standard of USP and EP. Methods The impurities 1b,1c,and 1d were synthesized from 3,5-bis(trifluoromethyl) acetophenone through asymmetrical catalytic reduction reaction,condensation reaction,Grignard reaction ,catalytic hydrogenation and substitution. The impurity 1e was synthesized from(R)-α-methylbenzylamine through 7 reaction steps including esterification,reduc-tion,condensation ect. Results All the four related substances were confirmed by LC-MS and NMR. The results indicated that purity of the product surpassed 95%through HPLC. Conclusion These related substances can be taken as the references for the quality con-trol of aprepitant.

Objective To investigate the anti-ulcer effects of Albizia chinensis(Osbeck)Merr. extract on rats with acetic acid-induced chronic gastric ulcer and explore the anti-inflammatory mechanism. Methods Wistar male rats(n=50)were randomized in-to five groups:control,model,famotidine,Albizia chinensis extract 100 and 200 mg/kg groups. In the experiment,30%acetic acid was used to induce chronic gastric ulcer in rats. The anti-ulcer effects of A. chinensis extract were evaluated by measuring the changes in general behavior of rats,gastric tissue morphology and the ulcer area after 12 d treatments. Wistar male rats(n=48)were random-ized into three groups:control,model and A. chinensis extract(200 mg/kg)groups. At 3 d after operation,the animals were sacrificed and stomachs were rapidly removed and processed for subsequent assays. The contents of TNF-αand IL-6 were evaluated by ELISA. The activity of myeloperoxidase(MPO)was tested by o-dianisidine method. Furthermore Western blot was used to examine the phos-phorylation of P38 and JNK. Results Compared with the model group,the gastric ulcer areas of rats were reduced by 38.4%(P<0.05)and the activity of MPO declined by 37.3%(P<0.01)in A. chinensis extract(200 mg/kg)group. Meanwhile the contents of TNF-αand IL-6 in A. chinensis extract(200 mg/kg)group respectively decreased by 43.8%(P<0.01)and 32.7%(P<0.01)com-pared with the model group. A. chinensis extract(200 mg/kg)obviously suppresed the phosphorylation of P38(P<0.01),but phos-phorylation of JNK and expression of P38 and JNK remained nearly unaltered. Conclusion A. chinensis extract(200 mg/kg)exhibits a protective effect on acetic acid-induced chronic gastric ulcer,which might be relevant to anti-inflammation by inhibiting the p38 sig-naling pathway but not JNK signaling pathway. A. chinensis extract(200 mg/kg)has no effect on JNK signaling pathway.

Recently,programmed cell death 1/programmed cell death 1 ligand(PD-1/PD-L1)blockade has elicited clinical re-sponses and long-term remissions in a subset of patients with a broad spectrum of cancers. Unfortunately,a substantial number of pa-tients failed to respond to PD1/PD-L1 blockade. In this paper,we summarize our current understanding of the key factors accounting for the difference on treatment,and evaluate the dependability of several potential predictive biomarkers guiding PD1/PD-L1 blockade in cancer therapy. We also discuss a variety of combined treatments based on PD1/PD-L1 blockade.

The growing epidemic of drug-resistant tuberculosis has posed a great threat to people′s health and become a major public health and social problems. Early detection and standardized treatment of tuberculosis are of great significance to controlling its spread. In order to provide reference for better prevention and clinical treatment of tuberculosis,this paper reviews the current situa-tion of anti-tuberculosis drugs and mechanism of resistance and new potential drugs for treating tuberculosis.

Objection To investigate the main influencing factors for extracting total polysaccharides and two active adjuvant components from Poria cocos. Methods Extracting temperature was designed between 20℃-100℃,ratio of material/water was 1/5-1/20 (W/V),extracting time was 1-6 h,extracting frequency was 1-3 times,material size was crude slices~50 mesh,and extracting mode was standing or stirring. The sugar content was determined by phenol-sulfuric acid method and the reletive molecular mass of polysac-charides was determined with gel filtration chromatography. Monosaccharide compositions were analyzed with PMP-derivation and cap-illary electrophoresis. Results ①The extracting temperature should be below 70℃;②The ratio of material/water was suitable be-tween 1/5-1/20;③The extracting time might be within 2 h;④The extracting frequency should be no more than two times;⑤The raw material should be crushed before extracting;⑥The stirring was favorable for extracting polysaccharides. Conclusion The re-sults indicate that the extracting temperature,extracting frequency and stirring mode are important for extracting polysaccharides,and the cushing of the raw materials is helpful to extract the active adjuvant component of polysaccharides from P. cocos in higher yield.

Aptamers are kinds of short single-stranded deoxyribonucleic acid(ssDNA)or ribonucleic acid(RNA)selected in vitro using SELEX(systematic evolution of ligands by exponential enrichment). They can effectively bind various targets such as ami-no acids,carbohydrates,proteins,cells and viruses,with the advantages of simple operation,high sensitivity and low cost. This arti-cle outlines the basic principles,advantages and applications of aptamer technology. It also summarizes the features and hazards of ma-rine biotoxins,and introduces the application prospects of aptamer technology in the detection of marine biotoxins.