环境中内分泌扰乱化学物质及其监测与分析

激素是人和动物体内的重要化学信使,对生长、发育和生殖具有关键的调控作用.由于工业的发展,人类在改善自身生活条件的同时,自觉和不自觉地向环境中释放出大量的化学物质,环境中某些化学物质可以模仿天然激素的作用,扰乱人类和野生动物的内分泌系统的正常功能,损伤再生机能和产生恶性肿瘤,从而可能对人类健康和野生动物构成极大的威胁.     

环境内分泌干扰物对雌激素受体表达与转录激活的调控效应及分析技术

环境内分泌干扰物(Endocrine disrupting chemicals, EDCs)种类繁多,来源复杂,环境污染普遍,对野生动物与人类造成了不同程度的暴露。EDCs可通过调控机体内分泌系统,干扰心血管、生殖、神经等多个系统的正常功能,从而引起机体代谢综合征、肥胖症、神经毒性、生殖发育毒性和癌症等的发生发展。污染物调控雌激素受体(Estrogen receptors, ERs)产生内分泌干扰效应是当前EDCs研究的主要方向。本文围绕ERs的基本生理特征、ERs表达与转录激活的分析检测技术,及EDCs调控不同组织来源ERs的生物学意义进行系统综述,以期从ERs激动/拮抗效应的角度,为新型化学品的内分泌干扰效应筛选及分子机制解析提供科学思路。     

Analysis of Six Phenolic Endocrine Disrupting Chemicals in Surface Water and Sediment

An efficient and reliable method based on gas chromatography–mass spectrometry (GC–MS) was developed for the extraction and analysis of six phenolic endocrine disrupting chemicals (EDCs), such as 4-nonylphenol (4-NP), nonylphenol-mono-ethoxylate (NP1EO), nonylphenol-di-ethoxylate (NP2EO), 4-tert-octylphenol (4-t-OP), bisphenol A (BPA) and 4-cumylphenol (4-CP) in surface water and sediment. The method was developed by using microwave-assisted extraction (MAE), solid phase extraction (SPE) and derivatization procedure. The MAE procedures were performed by optimizing three key process factors, consisted of extraction solvent, extraction temperature and holding time, affecting the extraction efficiency from sediment samples. For SPE, various parameters that may affect the recovery efficiency of water samples, such as SPE phase cartridge, elution solvent, as well as pH of water samples, were investigated. A series of derivatization conditions, such as derivatization reagent, reaction temperature and reaction time, were improved. The method achieved good repeatability and reproducibility with relative standard deviations <13% for all target EDCs in the both samples. Satisfactory recoveries for spiked water and sediment samples ranged from 85 to 101% and 74 to 105%, respectively. The limits of quantification varied from 0.20 (4-t-OP) to 11.50 ng L^?1 (NP2EO) and from 0.31 (4-t-OP) to 9.50 ng g^?1 dry weight (dw) (NP2EO) for water samples and sediment samples, respectively. The established method was successfully applied to the analysis of target EDCs in surface water and sediment samples collected from Caohai site of Dianchi Lake, China. The results showed that NP1EO, NP2EO and BPA were the three dominant phenolic EDCs in the site, reaching 114, 97 and 149 ng L^?1 in surface water, while 444, 186 and 178 ng g^?1 dw in surface sediment, respectively.     

环境水体中酚类EDCs前处理技术及分析方法研究进展

环境内分泌干扰物(EDCs)是指干扰生物体内保持自身平衡和调节发育过程中天然激素的合成、分泌、运输、代谢、结合、反应、消除等生物过程的外源性化学物质,这类物质的存在会干扰人类和野生动物的内分泌系统,带来生殖障碍、发育异常、免疫功能减弱等问题。EDCs,尤其是使用最为广泛的酚类EDCs,在水环境中的污染特征研究已是当前科学界和公众共同关注的热点问题之一。环境样品基质非常复杂,使得痕量酚类EDCs的分析检测难度较大。该文对近年来环境水体中酚类EDCs的分析方法进行了综述,分别对样品前处理与检测分析技术进行了介绍,其中前处理技术包括样品萃取、样品净化和样品衍生化,检测分析技术包括化学分析和仪器分析。最后对酚类分析方法进行了展望。     

多氯联苯的羟基化代谢产物及其内分泌干扰机制

羟基多氯联苯是典型持久性有机污染物(POPs)--多氯联苯在生物体内的主要活性代谢产物,已在许多野生动物和人体内被检出.由于其化学结构与天然雌激素、甲状腺激素十分类似,因此羟基多氯联苯的内分泌干扰效应近年来已开始受到国际上的高度关注.本文对多氯联苯的代谢途径、羟基多氯联苯在生物体内的浓度水平、内分泌干扰及其多种毒性作用机制进行了综述.有关对多氯联苯的活性代谢产物--羟基多氯联苯的深入研究,将有助于进一步揭示多氯联苯的毒性机制,为我国早日建立有效的POPs污染危害评价与早期预警系统提供科学依据.     

Subtle Modification of Imine-linked Helical Receptors to Significantly Alter their Binding Affinities and Selectivities for Chiral Guests

Aromatic helical receptors P- 1 and P- 2 were slightly modified by aerobic oxidation to afford new receptors P- 7 and P- 8 with right-handed helical cavities. This subtle modification induced significant changes in the binding properties for chiral guests. Specifically, P- 1 was reported to bind d -tartaric acid (K_a=35500 M⁻¹), used as a template, much strongly than l -tartaric acid (326 M⁻¹). In contrast, its modified receptor P- 7 exhibited significantly reduced affinities for d -tartaric acid (3600 M⁻¹) and l -tartaric acid (125 M⁻¹). More dramatic changes in the affinities and selectivities were observed for P- 2 and P- 8 upon binding of polyol guests. P- 2 was determined to selectively bind d -sorbitol (52000 M⁻¹) over analogous guests, but P- 8 showed no binding selectivity: d -sorbitol (1890 M⁻¹), l -sorbitol (3330 M⁻¹), d -arabitol (959 M⁻¹), l -arabitol (4970 M⁻¹) and xylitol (4960 M⁻¹) in 5% (v/v) DMSO/CH₂Cl₂ at 25±1 °C. These results clearly demonstrate that even subtle post-modifications of synthetic receptors may significantly alter their binding affinities and selectivities, in particular for guests of long and flexible chains.     

超高效液相色谱-串联质谱多目标分析生物样品中的微量内分泌干扰污染物

建立了生物样品中9种微量内分泌干扰物(EDCs)的多目标分析方法.采用旋涡振荡-超声波辅助萃取,结合凝胶渗透色谱(GPC)除去大分子有机物干扰,再经硅胶柱层析进一步净化,最后应用超高效液相色谱-串联质谱(UHPLC-MS/MS)检测.GPC采用乙酸乙酯-环己烷混合溶液(1:1,V/V)为流动相,选择12~28 mL为目标化合物馏分的收集段;质谱采用电喷雾离子源正离子模式和大气压化学电离源负离子模式,数据采集为多重反应监测模式.方法回收率为65.2%~118.0%,定量限为0.1~9.7 ng/g dw(干重).采用本方法初步分析了珠江水系鲤鱼脊肉中的内分泌干扰污染物,结果表明,除均二苯腺和三氯卡班未被检出外,其它内分泌干扰污染物的含量为0.1~22.6 ng/g dw.     

固相萃取-衍生化-气相色谱/质谱测定水中类固醇类环境内分泌干扰物

建立了固相萃取-衍生化-气相色谱/质谱联用同时测定水中4种类固醇类环境内分泌干扰物雌酮(E1)、17β-雌二醇(E2)、17α-乙炔基雌二醇(EE2)、雌三醇(E3)的分析方法.通过对比衍生化试剂 N,O-双三甲基硅基三氟乙酰胺(BSTFA)和N-甲基-N-三甲基硅基三氟乙酰胺(MSTFA)的衍生化条件及效果,解释了文...     

水环境中内分泌扰乱化学物质检测方法研究--烷基酚、氯代酚和双酚A的GC-MS分析

目前,在许多发达国家EDCs问题已经引起公众和科学家的极大重视,因为它不仅对当代人类和野生动物产生负面影响,而且这种作用会影响到子孙后代.     

Synthesis of Glutamic Acid-based Cluster Galactosides and Their Binding Affinities with Liver Cells

Structurally well defined di-, tri- and tetra-valent cluster galactosides were synthesized in a convenient way.Oligo-glutamic acids were assembled as scaffolds. The presence of amine groups in these three ligands is expected to couple with drugs or genes for delivery. The binding affinities of these cluster galactoses to liver cells were determined by in vitro binding studies. Among them, the tetravalent cluster galactose (19) showed the highest affinity to liver cell. It is therefore a promising targeting device for the specific delivery of drugs or genes to parenchymal liver cells.     

卵黄蛋白原的分离测定及其在环境内分泌干扰物质筛选中的应用

环境内分泌干扰物的存在直接威胁野生动物的生存和人类的健康，对其作用机制及筛选方法的研究，已经成为环境科学研究的热点领域。近年来，卵黄蛋白原作为环境内分泌干扰物的“生物标志物”，得到了较深入的研究。本文讨论了卵黄蛋白原的分离测定方法及其在内分泌干扰物筛选中应用的最新进展，为建立更有效的卵黄蛋白分离测定方法及发展新的环境内分泌干扰物筛选技术提供参考。     

金属卟啉对杂环及DNA分子识别研究进展

介绍了近几年国内外关于组装金属卟啉对杂环分子、DNA碱基以及RNA的分子识别的研究进展, 并简述了本课题组对金属卟啉与杂环及药物分子复合物的理论研究工作. 金属卟啉广泛存在于自然界和生物体中, 此识别过程对研究和模拟生命体中各种细胞之间的相互作用具有重要意义. 组装后的金属卟啉可通过轴向配位、氢键及π-π堆积作用等识别杂环分子. 金属卟啉对DNA的识别主要有四种作用方式, 而金属卟啉对DNA以及RNA分子的识别主要靠疏水作用力、静电力以及自堆叠作用. 卟啉阳离子与DNA的结合位点受主体侧链取代基的空间结构影响. 金属卟啉对药物分子的识别靠配位键和氢键进行, 以配位键结合的复合物通常具有更高的结合能.     

高效液相色谱-串联质谱法测定人尿液中5种酚类内分泌干扰物

采用通用电喷雾离子源的高效液相色谱-串联质谱(HPLC-ESI MS/MS)分析技术,通过丹磺酰氯衍生化处理,建立了同时测定人尿液中双酚A(BPA)、三氯生(TCS)、炔雌酮(EE2)、雌酮(E1)、雌二醇(E2)5种酚类内分泌干扰物的高灵敏方法。5种酚类化合物在0.2～100μg/L质量浓度范围内线性关系良好,相关系数(r2)均在0.99以上,检出限(LOD)在0.02～0.27μg/L之间。在5、10、50μg/L加标水平下,平均回收率为85%～125%,相对标准偏差(RSD,n=3)为0.53%～14.4%。该方法灵敏度高、重现性好、回收率高、操作简单,可作为人尿液中酚类内分泌干扰物暴露分析的备选方法之一。     

低共熔溶剂分散液液微萃取-悬浮固化-高效液相色谱法测定水产品中3种内分泌干扰物的含量北大核心CSCD

将癸酸和香叶醇在10 mL玻璃管中以2∶1的物质的量之比混合,然后将混合物在80℃水浴锅中加热,直至形成稳定的低共熔溶剂(DES)。该溶剂易合成、低成本、低毒性且具有高生物降解性,是一种新型的疏水性DES,可用于水产品中内分泌干扰物的微萃取。取已粉碎的水产品样品1 g和乙腈2 mL置于5 mL离心管中,以转速2 000 r·min^(-1)涡旋振荡3 min。取上清液400μL,经0.45μm滤膜过滤,滤液与100μL DES混合,并迅速注入装有5 mL 80 g·L^(-1)氯化钠溶液的10 mL离心管中,以完成DES的分散。将上述离心管以转速3 500 r·min^(-1)离心5 min,然后置于冰浴中进行固化。将固化后所得样品溶解于150μL甲醇中,以Eclipse Plus C;色谱柱为分离柱,以体积比90∶10的甲醇-水的混合液为流动相,在激发波长228 nm,发射波长305 nm处测定双酚A、4-叔辛基苯酚和壬基酚等3种内分泌干扰物的含量。结果表明,DES在冰浴中固化,可促进其从水溶液中分离,简单且快速,利于萃取剂的收集。3种内分泌干扰物的质量分数均在0.25~10μg·g^(-1)内与其对应的峰面积呈线性关系,检出限(3S/N)均为0.075μg·g^(-1)。用此法对空白加标样品进行测定,测定值的日内和日间相对标准偏差(n=5)均小于4.0%。以空白样品为基体进行加标回收试验,所得回收率为78.7%~91.6%。     

金属-有机骨架ZIF-8@Fe3O4复合物的制备及其用于磁固相萃取对水中内分泌干扰物的测定

制备了金属-有机骨架ZIF-8@Fe_3O_4复合物,考察了ZIF-8生长次数、萃取时间、离子强度、pH值、解吸溶剂和解吸时间等对萃取和解吸的影响,并通过磁固相萃取结合高效液相色谱法将其成功用于水中双酚A、雌酚酮、壬基酚和辛基酚4种内分泌干扰物的检测。该方法对上述4种物质的线性范围为1.0～1 000μg/L,检出限为0.42～0.81μg/L,富集因子为61～144,日内和日间精密度分别为2.1%～4.3%和3.5%～5.8%。     

Synthesis of Novel Receptors From 7-Deoxycholic Acid and Studies on Their Cation Binding Properties

The synthesis and cation binding properties of chiral crown ethers derived from 7-deoxycholic acid along with their application in asymmetric Michael reaction are described.     

Binding of Androgen- and Estrogen-Like Flavonoids to Their Cognate (Non)Nuclear Receptors: A Comparison by Computational Prediction

Flavonoids are plant bioactives that are recognized as hormone-like polyphenols because of their similarity to the endogenous sex steroids 17β-estradiol and testosterone, and to their estrogen- and androgen-like activity. Most efforts to verify flavonoid binding to nuclear receptors (NRs) and explain their action have been focused on ERα, while less attention has been paid to other nuclear and non-nuclear membrane androgen and estrogen receptors. Here, we investigate six flavonoids (apigenin, genistein, luteolin, naringenin, quercetin, and resveratrol) that are widely present in fruits and vegetables, and often used as replacement therapy in menopause. We performed comparative computational docking simulations to predict their capability of binding nuclear receptors ERα, ERβ, ERRβ, ERRγ, androgen receptor (AR), and its variant AR^T877A and membrane receptors for androgens, i.e., ZIP9, GPRC6A, OXER1, TRPM8, and estrogens, i.e., G Protein-Coupled Estrogen Receptor (GPER). In agreement with data reported in literature, our results suggest that these flavonoids show a relevant degree of complementarity with both estrogen and androgen NR binding sites, likely triggering genomic-mediated effects. It is noteworthy that reliable protein–ligand complexes and estimated interaction energies were also obtained for some suggested estrogen and androgen membrane receptors, indicating that flavonoids could also exert non-genomic actions. Further investigations are needed to clarify flavonoid multiple genomic and non-genomic effects. Caution in their administration could be necessary, until the safe assumption of these natural molecules that are largely present in food is assured.     

MECC分离并测定高粱及玉米中7种农药类环境激素

用毛细管胶束电动色谱成功分离并测定了高粱和玉米中7种农药类环境激素(多菌灵、西玛津、莠去津、毒死蜱、溴氰菊酯、乙草胺和氯氰菊酯)的残留量。研究了电泳缓冲液及表面活性剂等因素的影响,在最佳分离条件(pH 9.0、20 mmol/L磷酸氢二钠+50 mmol/L SDS+5%乙腈为缓冲溶液,分离电压20 kV,检测波长222 nm,实验温度25℃,压力法进样,30 mbar×10 s)下,7种农药在28 min内得到基线分离,质量浓度与其峰面积在5.0～150μg.L-1范围内呈良好线性,检出限为0.6～3.0μg/L,回收率为97%～108%,相对标准偏差为2.2%～4.7%。该方法具有操作简单、快速方便及自动化程度高、重现性好等优点。     

Dramatic Enhancement of Binding Affinities Between Foldamer‐Based Receptors and Anions by Intra‐Receptor π‐Stacking

As a synthetic model for intra‐protein interactions that reinforce binding affinities between proteins and ligands, the energetic interplay of binding and folding was investigated using foldamer‐based receptors capable of adopting helical structures. The receptors were designed to have identical hydrogen‐bonding sites for anion binding but different aryl appendages that simply provide additional π‐stacking within the helical backbones without direct interactions with the bound anions. In particular, the presence of electron‐deficient aryl appendages led to dramatic enhancements in the association constant between the receptor and chloride or nitrate ions, by up to three orders of magnitude. Extended stacking within the receptor contributes to the stabilization of the entire folding structure of complexes, thereby enhancing binding affinities.