壳聚糖固定化杂大环Cu(Ⅱ)配合物及其催化S-亚硝基硫醇释放NO

利用壳聚糖的轴向配位作用固定化杂大环Cu(Ⅱ)配合物,并利用红外光谱(FT IR)和扫描电镜(SEM)等现代分析手段对其进行了结构和组成表征。对关键中间体L进行了常规合成法和微波合成法考察。结果表明:微波法具有操作简单、反应时间短、条件温和、产率高及副反应少等优点,并探讨了微波合成法合成杂大环中间体L的最佳合成条件:以甲醇做溶剂,在m(二乙撑三胺)∶m(2,2′-(乙基氧)-双苯甲醛)为1∶1、微波功率为400 W、60℃下微波反应0.5h。并在模拟生理条件(pH=7.40,37℃)下,利用Gress试剂法考察了目标配合物催化S-亚硝基硫醇释放NO性能。结果表明:目标配合物具有稳定催化释放一氧化氮性能。     

二苯胺一步法合成4—亚硝基二苯胺

研究了一步法合成４ － 亚硝基二苯胺的影响因素,得出最佳工艺条件：ｎ（ 氯化氢）∶ｎ（ 二苯胺） ＝ ３∶１ ,反应温度２０ ～３０ ℃,反应时间４ ｈ,ｐＨ 值６ ～７。产品收率大于９８％ ,产品质量分数在９９％ 以上。     

1,5-萘二硫醇的合成

硫族元素有机化合物在材料中的应用 ,已成为当今有机化学研究领域的重要课题之一 [1] 。 1 ,5—萘二硫醇是制备半导体材料的重要前体化合物。我们曾经用 Sn Cl2 .2 H2 O[2 ] 、Zn粉及 Zn—Hg[3] 齐为催化剂 ,进行了 1 ,5—萘二硫醇制备研究 ,但收率较低 ,而且 Zn—Hg齐方法有大量汞残杂析出 ,对环境危害很大。因此我们对 1 ,5—萘二硫醇的合成方法进行了改进研究。合成路线如下 :1　实验部分1 .1　仪器与试剂2 4 0 0型元素分析仪 (美国 ) ;V arian MAT2 1 2型快原子轰击质谱仪 (美国 ) ;Jas co FT—IR80 0 0型红外光谱仪 (日本 ) ;J…     

1,5-萘二硫醇的简便合成

以Zn为催化剂,1,5-萘二磺酸钠、PCI5为原料合成了1,5-萘二硫醇,化合物结构经^1HNMR、IR和元素分析确证。结果表明该合成方法收率高、对环境污染少、适合于工业化生产。     

1，6－己二硫醇的合成研究

以１，６－二溴己烷为原料，合成了一种重要的鸡肉味香料１，６－己二硫醇，产率８５．０％。同时报道了一种简便的以１，６－己二醇为原料制备１，６－二溴己烷的方法，产率８９．５％。     

1，6－己二硫醇的合成研究

以１，６－二溴己烷为原料，合成了一种重要的鸡肉味香料１，６－己二硫醇，产率８５．０％。同时报道了一种简便的以１，６－己二醇为原料制备１，６－二溴己烷的方法，产率８９．５％。     

2,6-二甲基-4-亚硝基苯酚的合成研究

以2,6-二甲基苯酚为基本结构单元,对橡胶助剂中间体2,6-二甲基-4-亚硝基苯酚进行合成研究。结果表明,最佳反应条件为:亚硝酸钠水溶液滴加时间2h,保温反应时间2h,反应温度20℃,反应原料摩尔比n(2,6-二甲酚)∶n(浓硫酸)∶n(亚硝酸钠)=1∶1.2∶1.2。该条件下,产物收率达到了92.3%,熔点167℃～170℃。     

O，S-二甲基硫代磷酰胺的合成研究

在催化剂作用下,O,O-二甲基硫代磷酰胺反应合成O,S-二甲基硫代磷酰胺,收率达到77%以上。     

2,6-二叔丁基-4-亚硝基苯酚的合成及表征

以2,6-二叔丁基苯酚、浓硫酸及亚硝酸钠为原料,在乙醇中合成了抗氧剂中间体2,6-二叔丁基-4-亚硝基苯酚,考察了溶剂种类、反应温度、反应时间、投料比和投料次序对反应的影响。结果表明,最佳工艺条件为：乙醇为溶剂,反应温度25℃,n（2,6-二叔丁基苯酚）∶n（浓硫酸）∶n（亚硝酸钠）=1∶1.1∶1.1,投料次序为先滴加浓硫酸,再滴加亚硝酸钠溶液,反应时间为2 h。在该条件下,产物重结晶收率为92.0%,产物色谱纯度≥99.7%。     

消毒副产物N-亚硝基二甲胺的预处理去除工艺

N-亚硝基二甲胺(NDMA)作为饮用水中一种新型的消毒副产物(DBPs),因其具有高致癌性逐渐成为研究热点。该文介绍了NDMA的毒性和对人体的危害,并通过对活性炭吸附、强化混凝、化学氧化、高级氧化、生物氧化、紫外光降解和膜处理六种饮用水预处理工艺进行了总结,分析了各工艺对NDMA以及其前体物质的控制效果。     

A Selective and Practical Synthesis of Nitroolefins

A straightforward and general synthesis of nitroolefins from nitric oxide (NO) and olefins is presented. The direct nitration of aromatic olefins, allyl compounds, and acrylic acid derivatives proceeds smoothly at room temperature with high regioselectivity and good yields. The advantages of this novel procedure compared to established nitration procedures are demonstrated.     

新型NO供体的合成研究及其体外NO释放性能

报道以阿司匹林、邻胺基苯甲酸和醋酸锰为原料合成含阿司匹林Mn2+配合物的中间体(1),以无水乙醇为溶剂,在35～45℃的条件下将(1)与NO反应成功合成了目标新型Mn-NO供体(2),并对目标化合物(2)的合成条件分别进行了探索性实验,确定了合成目标化合物(2)的优化条件.并通过元素分析、红外光谱、1HNMR、MS等手...     

Carbon Monoxide and Nitric Oxide as Examples of the Youngest Class of Transmitters

The year 2021 is the 100th anniversary of the confirmation of the neurotransmission phenomenon by Otto Loewi. Over the course of the hundred years, about 100 neurotransmitters belonging to many chemical groups have been discovered. In order to celebrate the 100th anniversary of the confirmation of neurotransmitters, we present an overview of the first two endogenous gaseous transmitters i.e., nitric oxide, and carbon monoxide, which are often termed as gasotransmitters.     

Nitric Oxide,Nitric Oxide Formers and Their Physiological Impacts in Bacteria

Nitric oxide (NO) is an active and critical nitrogen oxide in the microbe-driven nitrogen biogeochemical cycle, and is of great interest to medicine and the biological sciences. As a gas molecule prior to oxygen, NO respiration represents an early form of energy generation via various reactions in prokaryotes. Major enzymes for endogenous NO formation known to date include two types of nitrite reductases in denitrification, hydroxylamine oxidoreductase in ammonia oxidation, and NO synthases (NOSs). While the former two play critical roles in shaping electron transport pathways in bacteria, NOSs are intracellular enzymes catalyzing metabolism of certain amino acids and have been extensively studied in mammals. NO interacts with numerous cellular targets, most of which are redox-active proteins. Doing so, NO plays harmful and beneficial roles by affecting diverse biological processes within bacterial physiology. Here, we discuss recent advances in the field, including NO-forming enzymes, the molecular mechanisms by which these enzymes function, physiological roles of bacterial NOSs, and regulation of NO homeostasis in bacteria.     

Synthesis and characterization of poly(methylene disulfide) and poly(ethylene disulfide) polymers in the presence of a phase transfer catalyst

Poly(methylene disulfide) and poly(ethylene disulfide) were synthesized from the polycondensation of methylene dichloride and ethylene dichloride monomers, respectively, in the presence of benzyltriethylammonium chloride as a phase transfer catalyst. The structures of the synthesized polysulfides were confirmed via the elemental analysis, attenuated total reflectance Fourier transform infrared spectroscopy and X-ray diffraction techniques. Moreover, the thermal behaviors of synthesized poly(methylene disulfide) and poly(ethylene disulfide) were characterized using differential scanning calorimetry and thermogravimetric analysis methods. The synthesized poly(methylene disulfide) and poly(ethylene disulfide) have molecular weights of about 2262 and 2863 g/mol, respectively. In addition, the polymers have crystalline structures absorbed in the amorphous sections. However, the d-spacing of polymers’ crystalline parts was different. Moreover, poly(methylene disulfide) and poly(ethylene disulfide) have a two- and one-step degradation behavior, respectively.     

2,2′-Bipyridine-Modified Tamoxifen: A Versatile Vector for Molybdacarboranes

Investigations on the antitumor activity of metallacarboranes are sparse in the literature and limited to a handful of ruthena- and molybdacarboranes. In this study, the molybdacarborane fragment [3-(CO)₂-closo-3,1,2-MoC₂B₉H₁₁] was combined with a vector molecule, inspired by the well-known drug tamoxifen or 4,4′-dihydroxytamoxifen (TAM-diOH). The molybdacarborane derivative [3,3-{4-[1,1-bis(4-hydroxyphenyl)but-1-en-2-yl]-2,2′-bipyridine-κ²N,N′}-3-(CO)₂-closo-3,1,2-MoC₂B₉H₁₁] ( 10 ), as well as the ligand itself 4-[1,1-bis(4-hydroxyphenyl)but-1-en-2-yl]-2,2′-bipyridine ( 6 ) showed cytotoxic activities in the low micromolar range against breast adenocarcinoma (MDA-MB-231, MDA-MB-361 and MCF-7), human glioblastoma (LN-229) and human glioma (U-251) cell lines. In addition, compounds 6 and 10 were found to induce senescence and cytodestructive autophagy, lower ROS/RNS levels, but only the molybdacarborane 10 induced a strong increase of nitric oxide (NO) concentration in the MCF-7 cells.     

牛磺酸对新生大鼠心肌成纤维细胞一氧化氮系统的影响

目的观察牛磺酸(Taurine,Tau)在血管紧张素Ⅱ(AngiotensinⅡ,AngⅡ)诱导新生大鼠心肌成纤维细胞(Cardiac fibroblast,CFb)增殖的过程中对诱导型一氧化氮合酶-一氧化氮(iN0S-NO)系统的影响,以揭示Tau抑制CFb增殖的初步机制。方法胰酶消化法分离培养新生大鼠CFb,用AngⅡ诱导促进其增殖,采用MTT法检测细胞增殖;羟脯氨酸试剂盒检测胶原含量;ELISA法测定转化生长因子β1(TGF-β1)蛋白的含量;流式细胞仪检测细胞周期;硝酸还原酶法、分光光度法和免疫荧光法检测CFb NO含量、一氧化氮合酶(iNOS)活性和iNOS蛋白的表达。结果Tau(40、80和160mmol/L)可抑制AngⅡ诱导的CFb增殖、胶原合成增加及TGF-β1蛋白含量增多,同时使细胞G0/G1期百分率增加,S期细胞百分率降低,并明显提高CFb NO含量、iNOS的活性及iNOS蛋白的表达量,且呈现剂量依赖性。结论牛磺酸通过提高CFbiNOS-NO系统的活性,拮抗AngⅡ的部分生物效应,致使CFb的增殖和胶原合成受到抑制。     

The Functional Diversity of Nitric Oxide Synthase Isoforms in Human Nose and Paranasal Sinuses: Contrasting Pathophysiological Aspects in Nasal Allergy and Chronic Rhinosinusitis

The human paranasal sinuses are the major source of intrinsic nitric oxide (NO) production in the human airway. NO plays several roles in the maintenance of physiological homeostasis and the regulation of airway inflammation through the expression of three NO synthase (NOS) isoforms. Measuring NO levels can contribute to the diagnosis and assessment of allergic rhinitis (AR) and chronic rhinosinusitis (CRS). In symptomatic AR patients, pro-inflammatory cytokines upregulate the expression of inducible NOS (iNOS) in the inferior turbinate. Excessive amounts of NO cause oxidative damage to cellular components, leading to the deposition of cytotoxic substances. CRS phenotype and endotype classifications have provided insights into modern treatment strategies. Analyses of the production of sinus NO and its metabolites revealed pathobiological diversity that can be exploited for useful biomarkers. Measuring nasal NO based on different NOS activities is a potent tool for specific interventions targeting molecular pathways underlying CRS endotype-specific inflammation. We provide a comprehensive review of the functional diversity of NOS isoforms in the human sinonasal system in relation to these two major nasal disorders’ pathologies. The regulatory mechanisms of NOS expression associated with the substrate bioavailability indicate the involvement of both type 1 and type 2 immune responses.     

富氧条件Co/H-ZSM-5催化剂上CH4选择催化还原NO的研究

采用离子交换法制备了一系列具有不同硅铝比和不同Co负载量的Co/H-ZSM-5催化剂样品。富氧条件下考察了硅铝比、Co负载量、空速、O₂浓度及酸位对催化剂选择催化还原活性的影响。并对其进行了XRD、BET、H₂-TPR和DRS-UV-vis等表征。催化结果表明，催化剂的催化活性随Co负载量的增加而增加，随硅铝比的增加而减少；NO转化率随着空速的增加而降低。O₂体积分数为2%时，NO达最大转化率。表征结果表明，Co²⁺为活性中心，酸中心的存在对催化活性有一定的促进作用。