4-表河豚毒素的结构表征与毒力测定研究

目的对制备获得的4-表河豚毒素(4-epiTTX)高纯样品进行结构确证与毒性测定。方法采用LCFLD检测法测定4-epiTTX样品纯度,采用HRMS、1 H NMR和13 C NMR对样品进行结构表征;开展4-epiTTX对小鼠的急性毒性试验。结果4-epiTTX样品纯度为98.72%,样品的HRMS图谱信息与4-epiTTX相对分子质量吻合,1 H NMR和13 C NMR数据与文献报道相符;测得4-epiTTX对小鼠的半数致死量(LD50)为(350.83±4.11)μg·kg-1。结论4-epiTTX与河豚毒素(TTX)的结构差别仅在于C-4上羟基为直立键。4-epiTTX有很强的毒性,...     

高纯脱水河豚毒素的结构表征与毒力测定研究

目的对制备的高纯脱水河豚毒素(Anh-TTX)样品进行结构验证与毒力测定。方法采用LC-FLD检测法分析Anh-TTX样品纯度,采用MS和~1H NMR对样品进行结构验证;进行高纯Anh-TTX对小鼠的LD_(50)测定。结果Anh-TTX样品纯度为98.3%,样品MS图谱信息与Anh-TTX的结构完全相符,~1H NMR数据与文献报道值基本一致;测得高纯Anh-TTX对小鼠的LD_(50)为(1862±6)μg·kg~(-1)。结论Anh-TTX样品的纯度高,得到MS和~1H NMR的确证。Anh-TTX对小鼠有较强毒性,但毒力远低于河豚毒素(TTX)。     

河豚毒素的药理作用及临床应用

本文介绍了河豚毒素（TTX）的化学特性、药理作用及临床应用。     

反相离子对-高效液相色谱法测定河豚毒素

目的建立了反相离子对-高效液相色谱法测定河豚毒素含量的方法。方法选用SHIMADZUODS色谱柱(150×6mm5μm),以0．2％(v／v)醋酸液为流动相,流速为1．2mL／min,检测波长为230nm。结果河豚毒素线性范围20～100μg／mL,r=0．9960(n=5);回收率为93．32％,RSD=5．41％(n=5);日内精密度为6．10％,日间精密度为7．42％(n=5)最低检测限50ng。结论方法准确、快速、简便,可作为迅速确定河豚毒素含量的测定方法。     

河豚毒素对斑马鱼的急性毒性研究

目的 研究河豚毒素对斑马鱼的急性毒性。方法 在斑马鱼中用最大非致死浓度(MNLC)和10%致死浓度(LC₁₀)测定和评估河豚毒素的急性毒性。结果 经Origin 8.0软件模拟,得出河豚毒素对斑马鱼急性毒性MNLC为8.62μmol/L,LC₁₀为15.2μmol/L。在本实验条件下,16.0μmol/L及以上浓度河豚毒素可诱发斑马鱼心包水肿和心律异常,终点时出现部分或全部死亡。河豚毒素的急性毒性靶器官是心脏和肝脏,主要表现为心包水肿、心律异常和卵黄囊吸收延迟,毒性出现浓度为0.958μmol/L。结论 河豚毒素对斑马鱼具有一定的心脏和肝脏毒性,且其毒性与河豚毒素的浓度相关。     

河豚毒素及其注射剂中有关物质的分离与测定

河豚毒素 (ｔｅｔｒｏｄｏｔｏｘｉｎ)是由河豚鱼的卵和肝脏中提取出来的 ,对人和动物有极毒 ,给药途径为肌肉注射 ,对人的半数致死量 (ＬＤ50 )为 10 μｇ·ｋｇ- 1·ｄ- 1。另一方面药理试验表明 ,河豚毒素有镇痛作用 ,在戒毒方面有显著效果。在河豚毒素的研究中 ,有关河豚毒素分离测定的研究 ,在已报道的综述方法[1] 中生物法是最早被采用的方法 ,但该方法重现性差 ;紫外法和气相色谱法虽然有很大改进 ,但它们均需对样品进行衍生化处理 ,方法繁琐。此外 ,荧光法[2 ] 、毛细管电泳法[3] 等也曾被采用但均不理想。本文采用高效液相色谱法对…     

河豚毒素处方前初步研究

目的 考察河豚毒素（TTX）在不同溶剂中的溶解性及稳定性,以及温度和pH值对稳定性的影响。方法 配制TTX不同介质的溶液,采用高效液相色谱法（HPLC）测定其在不同温度、不同pH缓冲液中的浓度,分析计算其溶解度及稳定性。结果 TTX在pH值为3.5时溶解度最大,随着pH值增加其溶解度逐渐降低。TTX在强碱条件下降解最为迅速,在70 ℃条件下、0.1 mol/L的氢氧化钠溶液中,20 min即完全降解。稳定性试验结果同样证明TTX在碱性条件下的稳定性最差,在37 ℃、pH值=7.4的磷酸缓冲盐溶液（PBS）中,TTX浓度在1~10 h时开始持续降低,28天降解率为88.07±0.27%。结论 TTX易溶于pH值=3.5的酸性水溶液,几乎不溶于碱性水溶液。其稳定性与温度、介质pH值密切相关,在酸性水溶液中较为稳定,在碱性条件下易降解,温度升高会加速其降解过程。     

河豚毒素实验疫苗对小鼠口服河豚毒素中毒的免疫保护效应

目的　开发河豚毒素 (TTX)的抗毒疫苗。方法　TTX与载体蛋白中国鲎血蓝蛋白 (TTH)、破伤风类毒素 (TT)和牛血清白蛋白 (BSA)化学偶联 ,分别制成免疫抗原TTX TTH和TTX TT ,检测抗原TTX BSA。经腹腔或皮下注射免疫原 (用Freund佐剂 ) ,免疫BALB/c小鼠 ;每组 12只 ;5个月内接受免疫原累计量 375 μg/鼠。定期采集动物血清 ,ELISA法监测血清中抗体质量 (滴度及亲和力 )。经igTTX的生理盐水攻击免疫鼠 ,以检验抗毒效价 ;首次剂量6 30 μg·kg- 1,间隔 2～ 3周后提高剂量再次攻击活存动物 ,观察攻毒实验后症状 ,记录 2 4h存活率及死亡鼠的存活时间。结果　所试两种人工抗原的抗毒效应无明显差异。免疫鼠经ig 6 30 ,80 0 ,12 0 0 ,15 0 0 ,2 0 0 0 μg·kg- 1TTX攻毒时 ,存活率分别为10 0 % ,95 % ,90 % ,70 %和 4 5 % ;测得半数死亡剂量约为 2 0 0 0 μg·kg- 1。免疫鼠经 2～ 5次igTTX重复攻毒 ,86 %动物累积耐受剂量高于 3.5mg·kg- 1;4 3%动物累积耐受剂量高于 5 .5mg·kg- 1。中毒对照动物ig 6 0 0 μg·kg- 1TTX全部死亡。结论　研制的TTX的化学实验疫苗可高效预防TTX口服攻毒 ,免疫预防是对抗TTX中毒很有希望的途径     

亲水液相色谱-质谱联用法测定河豚子中的河豚毒素

目的:建立河豚子中河豚毒素的亲水液相色谱三重四极杆质谱联用(LC-MS/MS)定量检测方法。方法:样品经匀浆,超声,乙腈沉淀离心后取上清液进样测定。色谱柱为Innovation HP Amide柱(100 mm×3.0 mm,5μm);流动相为乙腈-0.3%甲酸(体积比为70∶30);流速为0.5 mL.min-1;柱温为30℃;进样量5μL。以正离子多反应监测(MRM)方式进行定量分析,用于监测的离子对为[M+H]+320.1→162.1。结果:河豚毒素的线性范围为0.0313～2.00μg.mL-1,r=0.9999;检测限(S/N=3)为0.30 ng.mL-1,即3.0 pg;加样回收率在95.9%～102.7%之间。结论:本法简单、快速,灵敏度高,重复性好,适用于河豚子中河豚毒素的定量测定。     

Structure activity relationship, acute toxicity and cytotoxicity of antimycobacterial neolignan analogues

Objectives The study's aims were to evaluate the antimycobacterial activity of 13 synthetic neolignan analogues and to perform structure activity relationship analysis (SAR). The cytotoxicity of the compound 2‐phenoxy‐1‐phenylethanone (LS‐2, 1 ) in mammalian cells, such as the acute toxicity in mice, was also evaluated. Methods The extra and intracellular antimycobacterial activity was evaluated on Mycobacterium tuberculosis H37Rv. Cytotoxicity studies were performed using V79 cells, J774 macrophages and rat hepatocytes. Additionally, the in‐vivo acute toxicity was tested in mice. The SAR analysis was performed by Principal Component Analysis (PCA). Key findings Among the 13 analogues tested, LS‐2 ( 1 ) was the most effective, showing promising antimycobacterial activity and very low cytotoxicity in V79 cells and in J774 macrophages, while no toxicity was observed in rat hepatocytes. The selectivity index (SI) of LS‐2 ( 1 ) was 91 and the calculated LD50 was 1870 mg/kg, highlighting the very low toxicity in mice. SAR analysis showed that the highest electrophilicity and the lowest molar volume are physical‐chemical characteristics important for the antimycobacterial activity of the LS‐2 ( 1 ). Conclusions LS‐2 ( 1 ) showed promising antimycobacterial activity and very weak cytotoxicity in cell culture, as well as an absence of toxicity in primary culture of hepatocytes. In the acute toxicity study there was an indication of absence of toxicity on murine models, in vivo.     

Application of a toxicity identification evaluation for a sample of effluent discharged from a dyeing factory in Hong Kong

A first toxicity identification evaluation (TIE) was conducted in three phases using the Microtox test to identify the major toxicant(s) in effluent discharged from a dyeing plant in Hong Kong. In Phase I toxicity characterization indicated that anions were likely to be the major toxicants for the entire effluent. In Phase II concentrations of sulfite and other anions in the original and the anion exchange resin-treated effluent samples were determined by ion chromatography. Anions, which were found in the effluent at comparatively high concentrations and were suspected of being responsible for the toxicity to luminescent bacteria, were selected for further study in Phase III. Investigation in Phase III using the spiking and mass balance approaches confirmed that the sulfite ion was the major toxicant in the effluent.     

Distribution of tetrodotoxin, 6-epitetrodotoxin, and 11-deoxytetrodotoxin in newts

Tetrodotoxin was detected in all nine species of newts tested, 6-epitetrodotoxin in six species, and 11-deoxytetrodotoxin in five species. Only one species lacked the analogues, thus suggesting that the analogues were common metabolites among newts. Toxin levels were high in Taricha granulosa and Notophthalmus viridescens followed by Cynops spp. Distinct differences in toxin contents and profiles existed among species and tissues.     

两面针中化学成分的分离鉴定及活性测定

目的研究两面针根的化学成分,寻找具有抗炎活性的先导化合物。方法采用硅胶、反相ODS、Sephadex LH-20等柱色谱以及高效液相色谱等手段分离纯化,并通过理化性质和波谱数据鉴定化合物的结构;利用酶标仪测定吸光度,计算样品的一氧化氮(NO)释放抑制率;MTT法测定细胞存活率。结果从该植物中分离得到13个化合物,分别被鉴定为茵芋碱(skimmianine,1)、白鲜碱(dictamnine,2)、zanthobungeanine(3)、zanthodioline(4)、N-methylflindersine(5)、鹅掌楸碱(liriode-nine,6)、L-芝麻素(L-sesamin,7)、β-香树脂醇(β-amyrin,8)、豆甾-9(11)-烯-3-醇(stigmast-9,9)、十三烷胺(tridecane amine,10)、十四烷胺(tetradecane amine,11)、十七烷胺(heptadecanoic amine,12)、十九烷胺(nonadecane amine,13)。结论化合物3、4、8、10～13均为首次从两面针植物中分离得到;体外活性测试结果表明,化合物3具有温和的NO释放抑制活性,其IC50为37.26 mg.L-1。     

Methodological aspects of the determination of the acute inhalation toxicity of spray-can ingredients

Spray-can ingredients, if liberated in confined spaces, are potential health hazards for man. Thus, appropriate inhalation toxicity studies have to be performed in accordance with internationally recognized guidelines, e.g. the US Environmental Protection Agency: Federal Insecticide, Fungicide and Rodenticide Act (FIFRA no. 81-3) or OECD no. 403. One of the essential requirements of such guidelines is that test animals (preferably rats) be exposed to a steady-state concentration in a dynamic inhalation chamber for at least 4 hours. This is not easy to achieve with vapours released from a pressurized spray-can. The method described here makes it possible to expose experimental animals in an inhalation chamber to a steady-state concentration of intermittently released spray jets of constant doses per jet. Animal experiments and theoretical considerations (computer simulations) have shown that the method presented allows an up-to-date determination of the acute inhalation toxicity of spray-can ingredients.     

Actions of 6-epitetrodotoxin and 11-deoxytetrodotoxin on the frog skeletal muscle fiber.

6-Epitetrodotoxin (6-epiTTX) and 11-deoxytetrodotoxin (11-deoxyTTX), isolated from an Okinawan newt, Cynops ensicauda, were tested for sodium-channel blocking effects on the voltage-clamped frog skeletal muscle fiber. In 6-epiTTX, the C-6 -OH is in an epimeric position; in 11-deoxyTTX, C-11 has a methyl in place of a hydroxymethyl group. At pH 7.25, the ED50s for reducing INa are: 4.1 nM (TTX), 96 nM (6-epiTTX), and 445 nM (11-deoxyTTX). In each analogue, the lowered potency can be attributed energetically to the loss of a hydrogen bond. By complementarity, in the sodium-channel receptor for TTX, there must be a hydrogen-acceptor group for the C-6 -OH, and another for the C-11 -OH. Therefore, the TTX molecule is bound to the receptor through an ion-pair (for the guanidinium), and five hydrogen bonds, one each for the -OH on C-9, C-10, C-4, and, as now identified, for C-6 and C-11. Considering the three-dimensional structure of the toxin molecules, these binding sites must be located in a fold or a crevice of the channel protein. If glutamate 387 of rat brain sodium channel II is the ion-pairing site for the guanidinium group, then the carbonyl oxygen of asparagine 388 is the hydrogen acceptor for the C-9 and C-10 -OHs.     

薏苡仁多糖急性毒性及遗传毒性试验研究

目的了解薏苡仁多糖的毒理学安全性。方法小鼠急性毒性试验和遗传毒性试验（Ames试验、小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验）。结果薏苡仁多糖的小鼠经口LD50〉20g·kg^-1;在Ames试验、小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验中均呈阴性反应,未显示有遗传毒性作用。结论薏苡仁多糖基本无毒性。     

钙纳米粒子急性毒性及长期毒性试验

近年来纳米粒子的研制及应用已成为一个研究热点[1].该文观察了钙纳米粒子对小鼠的急性毒性和对大鼠的长期毒性,以评价钙纳米粒子的用药安全性.     

拉曼光谱快速检测盐酸左氧氟沙星注射液

目的:建立一种运用拉曼光谱技术快速鉴别、检查和测定盐酸左氧氟沙星注射液的方法。方法:以氧氟沙星、左氧氟沙星、盐酸左氧氟沙星以及盐酸左氧氟沙星注射液为研究对象,运用拉曼光谱技术对盐酸左氧氟沙星注射液进行快速鉴别、检查和含量测定。结果:拉曼光谱法可以鉴别出氧氟沙星消旋体和左氧氟沙星,辨别出不同pH的左氧氟沙星注射液的图谱差异并可用于盐酸左氧氟沙星注射液的含量测定。结论:本方法操作简便、快速无损,可成为注射剂快速检测的分析方法。