Organotins: Toxicology and biological effects

Organotins are currently one of the most studied groups of organometallic compounds; their novel and often unique chemical properties have intrigued chemists for over 100 years and, today, many of these compounds find extensive use in agriculture and industry. Over the years, however, a number of the organotins have been demonstrated to be toxic and there is now increasing concern that their widespread use may cause adverse effects within environmental and biological systems. This article reviews and updates the current literature concerning organotin toxicology. It identifies the various target organs and systems, discusses mechanisms and species susceptibility, and directs the reader to additional sources of more specialized information as appropriate.     

Synthesis and radioprotective action of silathiazolidines and germathiazolidines

We report on the synthesis and characterization of new sila‐ and germa‐thiazolidines derived from 2‐[1‐(1‐naphthyl)ethyl]‐2‐imidazoline. The radioprotective activity was evaluated in mice by intraperitoneal injection. A notable diminution in the toxicity and increase in radioprotective efficacy were shown for the organometallic derivatives compared with the unsubstituted organic precursors. For some of the cyclic compounds, a delay effect was observed tranducing a slow opening in vivo of the thiazolidine ring. Copyright © 2004 John Wiley & Sons, Ltd.     

水热法一步合成氮掺杂碳点及其应用于Cu(Ⅱ)离子检测

采用水热法以聚乙烯亚胺为原料一步制备氮掺杂荧光碳点。紫外-可见吸收光谱、荧光光谱以及透射电镜显示,所制备的碳点荧光性能优异、分散性好、且无团聚现象。Cu(Ⅱ)对所得的碳点表现出选择性荧光猝灭效果,这种现象可用于Cu(Ⅱ)检测。在0.1 mol/L PBS溶液中,荧光碳点的荧光强度随着Cu(Ⅱ)浓度的增加逐渐减弱。该方法对Cu(Ⅱ)检测的线性范围为50~150 μmol/L,检出限为10 μmol/L。细胞毒性测试结果表明,不同浓度的碳点对细胞活性影响均较小,其细胞毒性低。以上结果说明该碳点能成功检测Cu(Ⅱ)且细胞毒性低,在生物传感方面有潜在应用价值。     

揭秘VX神经毒剂

神经性毒剂属有机磷或有机磷酸酯类化合物,其主要通过不可逆性地抑制乙酰胆碱酯酶的作用导致乙酰胆碱的过度积累,从而产生特征性神经剂中毒的现象。对神经毒剂进行了简单介绍,概述了VX神经毒剂的结构、毒性及防治。     

The safety assessment of herbals with a new and ethical approach

The increasing use of plant medicines (herbals) in Europe needs a shared methodology to determine the toxicity and the daily exposure level to these drugs. For this reason, the European regulatory agencies have undertaken a study that could meet popular uses and toxicological research in different countries of the Union. Here we list some examples of the most used herbal drug classes and we propose a decision-making process based on their characteristics, their content in active principles and on the basis of the present scientific pharmacological and toxicological literature. The proposed decision tree actually makes easier for the assessor to quickly and accurately evaluate the accredited indexes for risk and toxicity assessment based on the preclinical literature data and using the correct classification that some of them may have because they are already present in medicinal products or used as food.     

Electrochemical Detection of Acetaminophen with Silicon Nanowires

Acetaminophen (APAP) is an antipyretic, analgesic agent, the overdose of which during medical treatment poses a risk for liver failure. Hence, it is important to develop methods to monitor physiological APAP levels to avoid poisoning. Here, we report an efficient, selective electrochemical APAP sensor made from depositing silicon nanowires (SiNWs) onto glassy carbon electrodes (GCEs). Electrocatalytic activity of the SiNW/GCE sensors was monitored under varying pH and concentrations of APAP using cyclic voltammetry (CV) and chronoamperometry (CA). CV of the SiNWs at 0.5 to 13 mmol dm⁻³ APAP concentrations was used to determine the oxidation and reduction potentials of APAP. The selective detection of APAP was then demonstrated using CA at +0.568 V vs Ag/AgCl, where APAP is fully oxidized, in the 0.01 to 3 mmol dm⁻³ concentration range with potentially‐interfering analytes. The SiNW sensor has the ability to detect APAP well within the detection limits for APAP toxicity, showing promise as a practical biosensor.     

Toxicity assessment of nickel using Aspergillus niger and its removal from an industrial effluent

Chemical analysis of electroplating effluent revealed the presence of very high concentrations of nickel (393 ppm) in the effluent. Bioassay was carried out to test the toxicity of nickel chloride to Aspergillus niger. In contrast to 50% conidial inhibition at 1.7 mM nickel, hyphal extension was affected even at a lower concentration (0.4 mM), suggesting that hyphae are more sensitive than conidia to nickel. An increase in nickel concentration resulted in a proportionate decrease in the hyphal extension. Nickel (II)-resistant mutants of A. niger M1, M2, and M3, were obtained using direct selection, stepwise adaptation, and ultraviolet mutation techniques. Biosorption of Ni (II) by the mutant M3 was 50% more than that of its parent strain.     

Consensus QSAR models estimating acute toxicity to aquatic organisms from different trophic levels: algae,Daphnia and fish

ABSTRACT

We report new consensus models estimating acute toxicity for algae, Daphnia and fish endpoints. We assembled a large collection of 3680 public unique compounds annotated by, at least, one experimental value for the given endpoint. Support Vector Machine models were internally and externally validated following the OECD principles. Reasonable predictive performances were achieved (RMSE_ext = 0.56–0.78) which are in line with those of state-of-the-art models. The known structural alerts are compared with analysis of the atomic contributions to these models obtained using the ISIDA/ColorAtom utility. A benchmarking against existing tools has been carried out on a set of compounds considered more representative and relevant for the chemical space of the current chemical industry. Our model scored one of the best accuracy and data coverage.

Nevertheless, industrial data performances were noticeably lower than those on public data, indicating that existing models fail to meet the industrial needs. Thus, final models were updated with the inclusion of new industrial compounds, extending the applicability domain and relevance for application in an industrial context. Generated models and collected public data are made freely available.     

香港海域毒性微藻Alexandium tamarense的麻痹性贝毒研究

对从香港海域底坭分离并培养的毒性微藻塔玛亚历山大藻（Alexandiumtamareuse）的毒性和麻痹性贝毒素的组成进行研究。由生物试验测得其毒性为4．11×10－6MU／cell，用高效液相色谱分析毒素的组成，结果表明所含麻痹性贝毒成分主要是膝沟藻毒素－2（GTX2），含量为94.13pg／cell，本研究所用的微藻毒素提取方法和高效液相色谱分析方法都比较容易和有效。