Effects of Hydrogen Peroxide and Ultrasound on Biomass Reduction and Toxin Release in the Cyanobacterium,Microcystis aeruginosa

Cyanobacterial blooms are expected to increase, and the toxins they produce threaten human health and impair ecosystem services. The reduction of the nutrient load of surface waters is the preferred way to prevent these blooms; however, this is not always feasible. Quick curative measures are therefore preferred in some cases. Two of these proposed measures, peroxide and ultrasound, were tested for their efficiency in reducing cyanobacterial biomass and potential release of cyanotoxins. Hereto, laboratory assays with a microcystin (MC)-producing cyanobacterium (Microcystis aeruginosa) were conducted. Peroxide effectively reduced M. aeruginosa biomass when dosed at 4 or 8 mg L⁻¹, but not at 1 and 2 mg L⁻¹. Peroxide dosed at 4 or 8 mg L⁻¹ lowered total MC concentrations by 23%, yet led to a significant release of MCs into the water. Dissolved MC concentrations were nine-times (4 mg L⁻¹) and 12-times (8 mg L⁻¹ H₂O₂) higher than in the control. Cell lysis moreover increased the proportion of the dissolved hydrophobic variants, MC-LW and MC-LF (where L = Leucine, W = tryptophan, F = phenylalanine). Ultrasound treatment with commercial transducers sold for clearing ponds and lakes only caused minimal growth inhibition and some release of MCs into the water. Commercial ultrasound transducers are therefore ineffective at controlling cyanobacteria.     

Over-the-Counter “Adrenal Support” Supplements Contain Thyroid and Steroid-Based Adrenal Hormones

Objective

To assess whether dietary supplements that are herbal and/or animal-derived products, marketed for enhancing metabolism or promoting energy, “adrenal fatigue,” or “adrenal support,” contain thyroid or steroid hormones.

Structures of Phytosterols and Triterpenoids with Potential Anti-Cancer Activity in Bran of Black Non-Glutinous Rice

Structures of some bioactive phytochemicals in bran extract of the black rice cv. Riceberry that had demonstrated anti-cancer activity in leukemic cell line were investigated. After saponification with potassium hydroxide, separation of the unsaponified fraction by reversed-phase high performance liquid chromatography (HPLC) resulted in four sub-fractions that had a certain degree of anti-proliferation against a mouse leukemic cell line (WEHI-3 cell), this being IC₅₀ at 24 h ranging between 2.80–467.11 μg/mL. Further purification of the bioactive substances contained in these four sub-fractions was performed by normal-phase HPLC. Structural characterization by gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance spectroscopy (NMR) resulted in, overall, the structures of seven phytosterols and four triterpenoids. Four phytosterols, 24-methylene-ergosta-5-en-3β-ol, 24-methylene-ergosta-7-en-3β-ol, fucosterol, and gramisterol, along with three triterpenoids, cycloeucalenol, lupenone, and lupeol, were found in the two sub-fractions that showed strong anti-leukemic cell proliferation (IC₅₀ = 2.80 and 32.89 μg/mL). The other sterols and triterpenoids were campesterol, stigmasterol, β-sitosterol and 24-methylenecycloartanol. Together with the data from in vitro biological analysis, we suggest that gramisterol is a significant anti-cancer lead compound in Riceberry bran extract.     

僵蚕抗凝成分仿生提取液的氨基酸序列分析

目的利用高效液相色谱-质谱法（LC-MS/MS）对僵蚕胃蛋白酶提取液的有效抗凝成分进行结构分析。方法采用Hola C₁₈ (2.1mm×100 mm,2.7 μm)色谱柱, 以0.05%甲酸水溶液-0.05%甲酸乙腈溶液为流动相,梯度洗脱, LC-MS/MS正离子模式分析,初步探究抗凝活性成分的相对分子量和氨基酸组成。结果僵蚕经胃蛋白酶解得到相对分子量500~1000的活性肽,且多肽为低于10个氨基酸组成的低聚肽。结论僵蚕蛋白类组分通过酶解为活性低聚肽发挥抗凝作用,胃蛋白酶提取法更具科学性。     

Effects of pH and Nutrients (Nitrogen) on Growth and Toxin Profile of the Ciguatera-Causing Dinoflagellate Gambierdiscus polynesiensis (Dinophyceae)

Ciguatera poisoning is a foodborne disease caused by the consumption of seafood contaminated with ciguatoxins (CTXs) produced by dinoflagellates in the genera Gambierdiscus and Fukuyoa. Ciguatera outbreaks are expected to increase worldwide with global change, in particular as a function of its main drivers, including changes in sea surface temperature, acidification, and coastal eutrophication. In French Polynesia, G. polynesiensis is regarded as the dominant source of CTXs entering the food web. The effects of pH (8.4, 8.2, and 7.9), Nitrogen:Phosphorus ratios (24N:1P vs. 48N:1P), and nitrogen source (nitrates vs. urea) on growth rate, biomass, CTX levels, and profiles were examined in four clones of G. polynesiensis at different culture age (D10, D21, and D30). Results highlight a decrease in growth rate and cellular biomass at low pH when urea is used as a N source. No significant effect of pH, N:P ratio, and N source on the overall CTX content was observed. Up to ten distinct analogs of Pacific ciguatoxins (P-CTXs) could be detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in clone NHA4 grown in urea, at D21. Amounts of more oxidized P-CTX analogs also increased under the lowest pH condition. These data provide interesting leads for the custom production of CTX standards.     

Pharmacokinetics and tissue distribution of methcathinone in rabbits

Methcathinone is one of the most commonly abused designer narcotics. The pharmacokinetics and tissue distribution of methcathinone is not well understood. In this study, methcathinone was intravenously or intragastrically administered to rabbits in order to investigate the pharmacokinetics and tissue distribution of methcathinone. The plasma concentrations of methcathinone and its metabolite cathinone at various timepoints post-methcathinone administration as well as the distribution of methcathinone and cathinone in various tissues were determined and quantified using a liquid chromatography-tandem mass spectrometry (LC-MS/MS). According to our results, the elimination of methcathinone and cathinone was faster after intravenous administration than that after intragastric administration. The methcathinone or cathinone concentration in the plasma dramatically dropped at 16–18 h post-methcathinone administration followed by a rebound. Gastric content and stomach tissue could be better samples for the identification of methcathinone abuse by oral administration while bile and stomach tissue could be ideal samples for the identification of methcathinone abuse in intravenous injection cases. The pharmacokinetic characteristics and tissue distribution pattern of methcathinone and its metabolite cathinone described in this study could benefit future study on identification and control of methcathinone abuse in forensic toxicological analysis.     

缬沙坦氨氯地平片在中国健康人体内的生物等效性研究

目的 评价缬沙坦氨氯地平片受试制剂与参比制剂在中国健康人体内的生物等效性和观察两制剂的安全性。方法 采用单中心、随机、开放、3周期、部分重复交叉设计。受试者经高脂高热餐后/空腹单剂量口服缬沙坦氨氯地平片受试制剂或参比制剂,采血至给药后72 h,周期间的清洗期为14 d。采用经方法学验证的LC-MS/MS检测血浆中缬沙坦和氨氯地平的浓度。选择Phoenix WinNonlin 软件(8.0版本),以非房室模型(non-compartmental analysis,NCA)计算缬沙坦、氨氯地平的药动学参数。采用参比制剂校正的平均生物等效性(reference-scaled average bioequivalence,RSABE)和平均生物等效性(average bioequivalence,ABE)方法评价缬沙坦的生物等效性,ABE方法评价氨氯地平的生物等效性。结果 缬沙坦在空腹条件下的Cmax、AUC0-t和AUC0-∞和在餐后条件下的Cmax的个体内变异系数均>0.294,采用参比制剂标度的平均生物等效性方法。计算得到单侧95%置信上限<0和几何均值比估计值为80.00%~125.00%。缬沙坦餐后条件下的AUC0-t和AUC0-∞的个体内变异系数<0.294,采用平均生物等效性方法,受试制剂与参比制剂的AUC0-t、AUC0-∞经对数转换后的几何均值比值的90%置信区间均在80.00%~125.00%内。综上,两制剂中的缬沙坦具有生物等效性。氨氯地平的Cmax、AUC0-t和AUC0-∞的个体内变异系数<0.294,采用平均生物等效性方法,受试制剂与参比制剂的Cmax、AUC0-t和AUC0-∞经对数转换后的几何均值比值的90%置信区间均在80.00%~125.00%内,表明两制剂中的氨氯地平具有生物等效性。结论 缬沙坦氨氯地平片受试制剂和参比制剂在中国健康人体内具有生物等效性。     

LC-MS/MS法测定大鼠血浆中低聚仿刺参糖胺聚糖的浓度及初步药物动力学研究

目的 建立大鼠血浆中低聚仿刺参糖胺聚糖（DAHG-1W）的LC-MS/MS测定方法,研究大鼠单次静脉注射DAHG-1W后的血浆药物动力学。方法 大鼠血浆样品经灰色链霉菌蛋白酶预处理、温和酸水解脱除岩藻糖支链、硫酸软骨素ABC酶降解成主链二糖并用2-氨基吖啶酮衍生后,进行液相色谱-质谱联用（LC-MS/MS）分析。色谱分离采用Cortecs UPLC T3色谱柱（2.1mm×150 mm, 1.6 μm）,流动相为10 mM乙酸铵水溶液-甲醇,梯度洗脱。质谱检测采用加热电喷雾离子源（H-ESI）,以负离子方式检测,AMAC标记的CS-4S6S和CS-2S4S（内标）的多反应监测（MRM）离子对均为m/z 732.0→652.4,保留时间分别为9.0和7.4 min。应用上述LC-MS/MS方法测定大鼠尾静脉注射DAHG-1W（5 mg·kg-1）后的血浆药物浓度,采用WinNonLin 6.0版软件计算药代动力学参数。结果 大鼠血浆中DAHG-1W在3.91-125.00 μg·mL-1浓度范围内线性关系良好;日内和日间精密度均小于15%,准确度为102.60%-111.17%;回收率为89.16%-103.35%;无明显基质效应且血浆样品稳定性好。大鼠静脉注射给药后DAHG-1W的血药峰浓度（Cmax）为（36.73±2.10）μg·mL-1,半衰期（t1/2）为（277.31±56.22）min,清除率（Cl）为（0.82±0.09）mL·min-1·kg-1,0-300 min药时曲线下面积（AUC0-t）为（3638.30±45.84）min·μg·mL-1。结论 本研究建立了大鼠血浆中DAHG-1W的LC-MS/MS分析方法,可应用于DAHG-1W在大鼠体内的药物动力学研究。     

新型蒽环类衍生物HYY-014大鼠体内药代动力学和组织分布的研究

目的：研究新型蒽环类衍生物HYY-014在大鼠体内的药代动力学和组织分布特征,为临床研究提供实验依据。方法大鼠单次尾静脉注射1．5 mg/kg的HYY-014后,采用LC-MS/MS法测定各时间点血浆和组织中HYY-014及其代谢物HYY-M3的浓度,药代动力学参数经DAS 3．0统计软件计算获得。结果采用统计矩方法处理药物浓度时间数据, HYY-014药代动力学参数 Cmax、T1/2、Vd、CL、AUC0-t、MRT0-t分别为(1628．6±618．6)μg/L、(24．4±3．6) h、(23．4±5．2) L/kg、(0．66±0．08) L/kg/h、(2219．5±276．9)μg/L ·h、(15．1±2．4) h;HYY-M3药代动力学参数Cmax、AUC0-t分别为(2．2±0．6)μg/L、(103．1±13．7)μg/L·h。静脉注射该药后,很快向机体的各组织广泛分布,且具有明显的靶向性,主要分布在脾、肾、肺、心脏、肝等组织,脑组织中浓度极低。结论静脉注射HYY-014组织分布广泛,具有明显的靶向性,肺、肝组织中的药物浓度均较高,不能通过血脑屏障。