氯代硝基二苯醚的多溴代反应

研究了氯代硝基二苯醚的多溴代反应，制备了5种新的氯溴混合卤代硝基二苯醚化合物，其结构经元素分析，IR和^1H NMR确证。     

黄酮类化合物研究(ⅩⅣ)——溴代异黄酮合成中的脱溴反应

我们曾报道2-溴间苯二酚在BF_3催化下酰化时的脱溴现象。本文在以下述反应制备6-溴代异黄酮时发现4-溴间苯二酚脱溴现象更为显著。     

饮用水消毒溴代副产物及其健康风险

受海水入侵影响严重的沿海地区,其饮用水源中常含有较高浓度的溴离子.研究表明,当原水中含有溴离子时,经氯化消毒、氯胺消毒或臭氧消毒后会增加溴代消毒副产物的形成,并且溴代副产物具有更高的遗传毒性.因此,对于溴代副产物的研究更具实际意义.现阶段国内对于消毒所产生的溴代副产物的研究很少.本文针对溴代副产物更高的健康风险,从其产生的原因、机理、影响因素及遗传毒性等方面进行了综述.     

溴代法合成硝基二苯醚类化合物

硝基二苯醚类化合物及其衍生物在农药、医药、杀菌及纺织品抗菌处理等领域有着广泛的应用。传统的合成非硝基苯环上含有取代基的二苯醚的方法，均为先合成含有相应取代基的苯酚，再与适当取代的邻或对硝基卤代苯醚化而得到目标物，对于非硝基环为三取代的化合物，其取代基均为2，4，6位。我们设想，先构筑硝基二苯醚母体，再通过硝基二苯醚的溴化反应，     

溴代丙酮酸乙酯的新合成法

溴代丙酮酸乙酯的新合成法黄锦霞，徐章煌，方国苏（湖北大学化学系武汉４３００６２）溴代丙酮酸乙酯是一种重要的化学物质，广泛用于医药、农药及天然产物的合成中［１］。它的合成已报道的有三条路线￣［２－４］，这些方法存在的不足之处是：（１）收率均不高（分别为...     

α—溴代芳基酮还原脱溴的新方法

α—溴代芳基酮的还原脱溴是有机化学中一种非常重要的官能团相互转换，通常有机合成中经常采用的是由芳基酮来制备α—溴代芳基酮，而反过来由α—溴代芳基酮来制备芳基酮的研究甚少，现在对碲使α—溴代芳基酮的还原脱溴反应进行研究，不仅拓宽了碲的应用范围，而且对将...     

溴代正辛烷的合成

以生产2-羟基-4-正辛氧基二苯甲酮的副产物溴化钾和正辛醇为原料,浓硫酸为催化剂,合成了溴代正辛烷。优化反应条件为:溴化钾100 mmol,n(溴化钾)∶n(正辛醇)∶n(浓硫酸)∶n(水)=1.00∶0.80∶0.92∶0.83,于110℃~120℃反应4 h。最佳反应条件放大8倍,收率仍可达93%。     

中水消毒中溴代副产物在总消毒副产物中的比例及其影响因素

中水氯消毒过程中,溴代副产物(Br-DBPs)在总消毒副产物(DBPs)中的比例受到有效氯投加量、氯化时间、pH、氨氮(NH3-N)以及预臭氧化的影响.结果表明,溴代三卤甲烷(THMs)较溴代卤乙酸(HAAs)更易生成.溴对DBPs的贡献随有效氯投加量增加而降低.在氯化时间低于5h时,溴对THMs的取代能力呈增加趋势而对HAAs的取代能力急剧降低,5h后延长氯化时间又会降低溴代THMs的生成比例.而且,溴代DBPs的比例在酸性和碱性条件下相对较低.NH3-N浓度增加导致DBPs总量减少但同时提高了溴对DBPs的贡献.另外进行短时间的预臭氧化会促进溴的取代能力;延长臭氧化时间则会降低溴代DBPs的生成比例.     

溴代季戊四醇的气相色谱法分析

采用ＢＰＸ－７０毛细管色谱柱对季戊四醇的－溴代、二溴代和三溴代产物进行了分离和定量分析,用内标法定量,本糖醇为内标物。该方法快速、简便、准确。     

Recent Progress on the Synthesis and Bioactivity of Marine Naturally Occurring Dienamides and Related Derivatives

The diverse biological activities of many marine naturally occurring dienamides have made them privileged structures for the development of new drugs. This review highlights the different synthetic approaches for the preparation of the marine naturally occurring dienamides and related pharmaceutically active derivatives.     

A Review: Halogenated Compounds from Marine Actinomycetes

Marine actinomycetes, Streptomyces species, produce a variety of halogenated compounds with diverse structures and a range of biological activities owing to their unique metabolic pathways. These halogenated compounds could be classified as polyketides, alkaloids (nitrogen-containing compounds) and terpenoids. Halogenated compounds from marine actinomycetes possess important biological properties such as antibacterial and anticancer activities. This review reports the sources, chemical structures and biological activities of 127 new halogenated compounds originated mainly from Streptomyces reported from 1992 to 2020.     

气相色谱-串联质谱法测定船用燃料油中的9种含氮化合物

采用气相色谱-串联质谱(GC-MS/MS)法建立了船用燃料油中9种含氮化合物的测定方法。样品以SPE小柱净化去除饱和烃后,通过二氯甲烷-乙醇(5∶1)溶液洗脱。用DB-5MS(30 m×0.25 mm×0.25μm)色谱柱分离,采用多反应监测(MRM)模式,外标法定量。结果表明,9种含氮化合物的色谱分离效果良好,在浓度1~1 000 mg/kg范围内与峰面积均呈线性关系。方法的定量下限(S/N=10)为0.18~0.43 mg/kg,平均加标回收率为85.3%~121.6%,相对标准偏差(RSD,n=6)均不大于6.8%。结果表明该方法快速可靠、准确简便,适用于船用燃料油中9种含氮化合物的检测。     

海洋环境监测实验室间比对试验结果分析评价

分别利用数理统计中Gurbbs检验、F检验和t检验方法对2011年参与东海外海域海洋环境监测的3家实验室比对试验结果进行分析评价.结果表明,3家实验室参与比对项目的数据精密度不尽相同,一些项目的监测结果实验室间存在系统误差.为确保全海域监测数据的一致性,质量保证与控制计划应不断完善.     

Natural Dietary Compounds in the Treatment of Arsenic Toxicity

Chronic exposure to arsenic (As) compounds leads to its accumulation in the body, with skin lesions and cancer being the most typical outcomes. Treating As-induced diseases continues to be challenging as there is no specific, safe, and efficacious therapeutic management. Therapeutic and preventive measures available to combat As toxicity refer to chelation therapy, antioxidant therapy, and the intake of natural dietary compounds. Although chelation therapy is the most commonly used method for detoxifying As, it has several side effects resulting in various toxicities such as hepatotoxicity, neurotoxicity, and other adverse consequences. Drugs of plant origin and natural dietary compounds show efficient and progressive relief from As-mediated toxicity without any particular side effects. These natural compounds have also been found to aid the elimination of As from the body and, therefore, can be more effective than conventional therapeutic agents in ameliorating As toxicity. This review provides an overview of the recently updated knowledge on treating As poisoning through natural dietary compounds. This updated information may serve as a basis for defining novel prophylactic and therapeutic formulations.     

The use of High-Performance Liquid Chromatography for the Speciation of Organotin Compounds

This review of the use of high-performance liquid chromatography (HPLC) for the speciation of organotin compounds which are primarily of significance in the marine environment is divided into sections on the basis of the different HPLC modes of separation. However, it should be noted that such a classification does not exist in reality. For instance, in an ion-pair reversed-phase system the separation mechanism for the ionic solutes may be ion-pair partitioning, or ion exchange, or both. The relevant practical information (e.g. column type, mobile phase, method of detection and detection limit) is presented in tabular form. A brief overview of the reported detection methods is included, because the delay in development of an easily interfaced, specific and sensitive detector has hindered the use of HPLC for organotin speciation studies. The literature reviewed covers publications from 1977, the year of the first application of HPLC to organotin speciation, to April 1995.     

静态顶空-气相色谱/质谱法同时检测环境水体中59种挥发性有机物

静态顶空法是一种简单、环保的样品前处理方法.通过对比试验,优化了影响静态顶空进样方法灵敏度的主要因素,确定了较佳的样品盐度(40%)、平衡温度(80℃)、平衡时间(10 min)、平衡压力(0.103 4 MPa)、定量环平衡时间(20 s)、进样时间(3 min)等前处理方法参数.采用优化后水样前处理条件及1.00 k V的检测器电压,59种挥发性有机物在特定的线性范围内,标准曲线线性相关系数均大于0.998,方法检出限为丙烯腈4.4μg/L、硝基苯7.6μg/L,其余挥发性有机物(VOCs)介于0.06~1.4μg/L,饮用水源水及污水处理厂进水实际样品加标回收率为60%~110%,精密度(RSD)为0.33%~22%(n=6).建立的静态顶空-气相色谱/质谱法(HS-GC/MS)水样前处理过程自动化,可同时对水中59种挥发性有机物进行检测.     

有机质谱人工智能解释——Z值二级族分类及在环境污染物质谱解释中的应用

本文叙述了环境污染物质谱人工智能解释计算机程序“DCP-AIMS-EP”.程序不仅基于质谱规则,而且基于依Z_i/Z_r值二级族分类构成的新型质谱知识库框架.程序在IBM486计算机上调试通过,并经225个环境污染物质谱和81个“非环境污染物”质谱验证评价,输出正确率达99.3%,置信度达95.3%.     

Tomato and Olive Bioactive Compounds: A Natural Shield against the Cellular Effects Induced by β-Hexachlorocyclohexane-Activated Signaling Pathways

The β-isomer of hexachlorocyclohexane (β-HCH) is a globally widespread pollutant that embodies all the physicochemical characteristics of organochlorine pesticides, constituting an environmental risk factor for a wide range of noncommunicable diseases. Previous in vitro studies from our group disclosed the carcinogenic potential of β-HCH, which contributes to neoplastic transformation by means of multifaceted intracellular mechanisms. Considering the positive evidence regarding the protective role of natural bioactive compounds against pollution-induced toxicity, micronutrients from olive and tomato endowed with the capability of modulating β-HCH cellular targets were tested. For this purpose, the solution obtained from a patented food supplement (No. EP2851080A1), referred to as Tomato and Olive Bioactive Compounds (TOBC), was administered to the androgen-sensitive prostate cancer cells LNCaP and different biochemical and cellular assays were performed to evaluate its efficiency. TOBC shows a dose-dependent significant chemoprotection by contrasting β-HCH-induced intracellular responses such as STAT3 and AhR activation, disruption of AR signaling, antiapoptotic and proliferative activity, and increase in ROS production and DNA damage. These experimental outcomes identified TOBC as a suitable functional food to be included in a diet regimen aimed at defending cells from β-HCH negative effects, recommending the development of tailored enriched formulations for exposed individuals.     

Secondary Formation of Aromatic Nitroderivatives of Environmental Concern: Photonitration Processes Triggered by the Photolysis of Nitrate and Nitrite Ions in Aqueous Solution

Aromatic nitroderivatives are compounds of considerable environmental concern, because some of them are phytotoxic (especially the nitrophenols, and particularly 2,4-dinitrophenol), others are mutagenic and potentially carcinogenic (e.g., the nitroderivatives of polycyclic aromatic hydrocarbons, such as 1-nitropyrene), and all of them absorb sunlight as components of the brown carbon. The latter has the potential to affect the climatic feedback of atmospheric aerosols. Most nitroderivatives are secondarily formed in the environment and, among their possible formation processes, photonitration upon irradiation of nitrate or nitrite is an important pathway that has periodically gained considerable attention. However, photonitration triggered by nitrate and nitrite is a very complex process, because the two ionic species under irradiation produce a wide range of nitrating agents (such as ^•NO₂, HNO₂, HOONO, and H₂OONO⁺), which are affected by pH and the presence of organic compounds and, in turn, deeply affect the nitration of aromatic precursors. Moreover, aromatic substrates can highly differ in their reactivity towards the various photogenerated species, thereby providing different behaviours towards photonitration. Despite the high complexity, it is possible to rationalise the different photonitration pathways in a coherent framework. In this context, this review paper has the goal of providing the reader with a guide on what to expect from the photonitration process under different conditions, how to study it, and how to determine which pathway(s) are prevailing in the formation of the observed nitroderivatives.