Development of A High Performance Liquid Chromatography-Tandem Mass Spectrometry Method for Determination of Lipophilic Toxins in Marine Shellfishes and Edible Safety Evaluation / 分析化学

In view of the present situation that edible marine shellfishes are combinedly contaminated by different kinds of lipophilic toxins, common lipophilic shellfish toxins in marine shellfishes were simultaneously detected by liquid chromatography-tandem mass spectrometry, and the safety risk of commercial marine shellfish was evaluated using the risk assessment method based on combined contamination of various toxins. Under the optimum conditions, satisfactory recoveries (63. 3％ - 88. 8％ ), precision ( relative standard deviations RSD≤14. 5％ ) and sensitivity (limit of detection in the range of 0. 5-2. 7 ng / g) of the method were achieved for all the analytes. Among the 105 commercially available shellfish samples, 42. 86％ of the samples had at least a kind of toxin. The highest average content was 47. 6 μg / kg of DTX1, which was the most serious contaminant for marine shellfishes. The total Expose Risk Index (∑ERI) was calculated based on Tolerable Daily Intake (TDI) and Acute Reference Dose (ARfD) of each toxin to evaluate the safety risk of commercial marine shellfish. The results showed that the ratio of commercially available marine shellfish with safety risk was 19. 05％ and the food safety risk of scallop was the highest. In summary, a new method based on the combined contamination of lipophilic shellfish toxins was successfully developed for risk assessment of the commercial marine shellfish. The proposed method is more harsh compared with the European Food Safety Authority (EFSA) regulation and can make shellfish consumers better to avoid the risk of poisoning.

Synergistic anti-tumor effects of axitinib and doxorubicin / 药学学报

To study the synergistic anti-tumor effects of doxorubicin and axitinib in combination, and investigate the underlying mechanism, we performed the MTT cytotoxic assay and tumor spheroids inhibition to investigate in vitro using A549 cells. The cell internalization, cell cycle distribution and DNA ladder experiments were performed to study the synergistic mechanisms. A549 xenograft was established in nude mice and adopted to study the in vivo anti-tumor effect of doxorubicin and axitinib. Results showed that combination of doxorubicin and axitinib exerted significantly higher cytotoxicity than each single drug, and induced a synergistic effect on tumor spheroids growth inhibition. The combination achieved the highest tumor growth suppression in vivo in the A549 xenograft. The combination of axitinib and doxorubicin exhibited the best anti-tumor effects both in vitro and in vivo than each single drug.

In vitro drug resistance of clinical isolated Brucella against antimicrobial agents

OBJECTIVE@#To explore the antibiotic resistance of Brucella melitensis and instruct rational use of antimicrobial agents in clinical treatment of Brucella infection.@*METHODS@#Bacteria were cultured and identified by BACTEC9120 and VITEK II automicrobic system. E-test was used to detect the minimal inhibitory concentration (MIC) of antimicrobial agents in the drug susceptivity experiment.@*RESULTS@#A total of 19 brucella strains (all Brucella melitensis) were isolated from 19 patients, who had fever between January 2010 and June 2012, and 17 samples were blood, one was bone marrow, the other sample was cerebrospinal fluid. The MIC range of ceftazidime was 2.0-8.0 mg/L, rifampicin was 0.06-2.0 mg/L, amikacin was 4.0-12.0 mg/L, levofloxacin was 2.0-8.0 mg/L, doxycycline was 8.0-32.0 mg/L, sulfamethoxazole-trimethoprim was 4.0-16.0 mg/L, ampicillin was 1.5-2.0 mg/L and gentamicin was 0.50-0.75 mg/L.@*CONCLUSIONS@#The drugs used in this experiment cover common drugs for treating Brucella. Meanwhile, the results are consistent with clinical efficacy. It is suggested personalized regimen according to patients' status in treatment of Brucella.

Studies on chemical constituents of the brown alga Dictyopteris divaricata / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the chemical constituents of the brown alga D. divaricata, and to test cytotoxicities of the purified compounds.</p><p><b>METHOD</b>Compounds were isolated by normal phase silica gel, Sephadex LH-20 chromatography and reverse phase HPLC techniques. Their structures were elucidated by spectroscopic methods including IR, MS and NMR. Cytotoxicities were tested by MTT method.</p><p><b>RESULT</b>Eight compounds were isolated from ethanolic extract of the brown alga D. divaricata and their structures were identified as (-)-torreyol (I), 4beta, 5alpha-dihydroxycubenol (II), 3-farnesyl-p-hydroxybenzioc acid (III), chromazonarol (IV), fucosterol (V), phenyl acetylamine (VI), 4-hydroxybenzoic acid (VII) and n-hexadecanoic acid (VIII).</p><p><b>CONCLUSION</b>Compound II and IV were obtained from this alga for the first time. The others were isolated from the Dictyotaceae algae for the first time. All compounds were inactive (IC50 > 10 microg x mL(-1)) against human tumor cell lines KB, Bel-7402, PC-3M, Ketr 3 and MCF-7.</p>

Bromophenols from the brown alga Leathesia nana / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the chemical constituents of the brown alga Leathesia nana.</p><p><b>METHOD</b>Compounds were isolated by normal phase silica gel, Sephadex LH-20 chromatography and reverse phase HPLC techniques. Their structures were elucidated with spectroscopic methods including IR, MS and NMR.</p><p><b>RESULT</b>Six compounds were isolated from ethanolic extract of the brown alga L. nana and their structures were identified as 2,2',3,3'-tetrabromo-4,4',5,5'-tetrahydroxydiphenyl methane, 2,2',3-tribromo-3', 4,4', 5-tetrahydroxy-6'-ethyloxymethyldiphenyl methane, 2,3-dibromo-4,5-dihydroxybenzyl alcohol, 2,3-dibromo-4,5-dihydroxybenzyl methyl ether, 3-bromo-4-hydroxybenzoic acid and 2-bromo-4,5-dihydroxybenzaldehyde.</p><p><b>CONCLUSION</b>All these compounds were obtained from this species for the first time.</p>