Synthesis and characterization of novel organotin monomers and copolymers and their antibacterial activity

Two novel organotin monomers, (N‐tri‐n‐butyltin) maleimide and m‐acryloylamino‐(tri‐n‐butyltin benzoate), were synthesized. Copolymerization of these two monomers with styrene was carried out in the bulk at 65°C using asobisisobutyronitrile as the free radical initiator. The monomers and copolymers were characterized by elemental analysis; the molecular weights of the copolymers were determined by GPC, solubility, IR, and ¹H‐NMR spectral studies. The antibacterial activities of the synthesized organotin monomers and copolymers toward various types of bacteria were also reported. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 740–745, 2000     

含硅烃基氯化锡的合成及其结构表征

用四（烃硅基亚甲基）锡和四氯化锡按不同的物质的量比进行反应,合成了相应的三烃基一氯化锡、二烃基二氯化锡和一烃基三氯化锡。讨论了影响反应的主要因素,并使用高效液相色谱对反应的进程进行跟踪检测。通过^1HNMR和元素分析,确定了这些化合物的结构。生物活性试验的初步结果显示,含硅二烃基二氯化锡对肺癌细胞SPC-A-1具有较好的体外抗癌活性。     

硒化二氢杨梅素的制备及抗肿瘤活性

以DMY为基底物、Na2SeO3为硒化剂制备硒化DMY。采用UV、FTIR、NMR、XRD、TG、原子荧光光度计表征其结构和性能，CCK-8法检测对HSC-3细胞增殖的影响，划痕实验研究对HSC-3细胞迁移的影响。结果表明，硒化DMY中仍存在黄酮基本母核、并新形成C-Se键，其中硒含量为6.54%±0.22%；DMY和硒化DMY均对HSC-3细胞的增殖和迁移有良好的抑制作用、抑制效果与浓度呈正相关，且DMY和硒化DMY对HSC-3细胞的半数抑制浓度（IC50）分别为25.27 μg/mL、21.27 μg/mL，DMY的硒化有效提高了对HSC-3细胞增殖和迁移的抑制能力。     

海蚯蚓蛋白酶基因的原核表达及其抗肿瘤活性

目的原核表达海蚯蚓蛋白酶基因,探讨其对肿瘤细胞增殖的抑制作用。方法根据环节动物门蚯蚓和单环刺螠丝氨酸蛋白酶c DNA序列多重比对获得的保守序列设计引物,从海蚯蚓肠道组织提取总RNA,经3′RACE和5′RACE技术分别克隆海蚯蚓蛋白酶c DNA序列的3′端和5′端,并进行拼接,对其编码的蛋白质作生物信息学分析;将海蚯蚓蛋白酶成熟肽的编码序列亚克隆至原核表达载体p ET-21a(+),转化大肠埃希菌BL21(DE3)进行诱导表达,采用组氨酸亲和层析柱纯化;MTT法检测重组蛋白的抗肿瘤活性。结果经3′端RACE技术获得约250 bp的海蚯蚓蛋白酶基因c DNA 3′端序列,再经5′RACE技术扩增获得约770 bp的c DNA 5′端序列,拼接可得海蚯蚓蛋白酶c DNA序列全长为880 bp,其编码蛋白含270个氨基酸,具有高度保守的GDSGGP序列;重组蛋白相对分子质量为27 000,主要以包涵体形式表达,约占菌体总蛋白的30%,上清纯化后纯度可达95%;重组蛋白酶对人肿瘤细胞增殖具有明显的抑制作用。结论原核表达了海蚯蚓蛋白酶,可明显抑制人肿瘤细胞的增殖,为抗肿瘤基因工程药物的研发提供了实验依据。     

载阿霉素透明质酸纳米粒的制备及其抗肿瘤活性

目的以组氨酸(histidine,His)修饰的透明质酸(hyaluronic acid,HA)为载体,阿霉素(doxorubicin,DOX)为模型药物,制备纳米粒DOX/His-HA,并分析其理化性质和体内外抗肿瘤活性。方法通过化学交联法将组氨酸与HA进行结合,采用超声法制备纳米粒DOX/His-HA。用DAWN HELEOSⅡ动态激光光散射仪测定His-HA纳米粒的粒径和Zeta电位,透射电镜观察其形态;紫外-可见分光光度计测定DOX/His-HA纳米粒中DOX的吸光度值,计算其包封率、载药量和DOX的体外释放度。采用MTT法检测DOX/His-HA对Hep G2细胞的生长抑制作用;摄入试验观察Hep G2细胞对DOX/His-HA的摄入情况;抑瘤试验分析DOX/His-HA的体内抗肿瘤活性。结果 His-HA纳米粒呈球形,粒径为230~480 nm,分散度良好,Zeta电位为-19.3~-13.5 m V。DOX/His-HA的载药量和包封率分别达到(8.14±0.09)%和(91.37±0.69)%。在前4 h内,DOX/His-HA纳米粒均存在明显突释现象;4 h后,DOX/HisHA纳米粒逐渐表现出一定的缓释性。随着组氨酸取代度的增加,DOX/His-HA的Hep G2细胞毒性增强。组氨酸取代度越高,DOX/His-HA越易被细胞摄入。DOX/His-HA具有更强的抑瘤效果,且对正常组织无明显的毒副作用。结论制备的DOX/His-HA纳米粒是一种缓释性和肿瘤靶向性良好的给药系统。     

Influence of the support structure on the activity,stability, and metal leaching of a polymer‐supported organotin chloride catalyst

Polymer‐supported organotin chlorides have been synthesized by suspension copolymerization of organotin‐functionalized styrenic monomers using a precipitating porogen. Their activities as reducing catalysts have been evaluated in the reduction of bromoadamantane by sodium borohydride. The influence of the length of the spacer arm between the tin atom and the polymer backbone on the activity and the tin leaching of the supported catalyst have been studied. The nature of the alkyl groups (butyl or phenyl) attached on the tin atom plays an important role on the stability toward successive reuse of the supported catalyst. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1297–1308, 2001     

Mechanism of organotin stabilization of poly(vinyl chloride). 1: The structure and equilibria of alkyltin thioqlycolates and their compatibility with PVC

A series of alkyltin thioglycolates was synthesized and their structure and equilibria with alkyltin chlorides studied by infrared analysis. Dynamic mechanical analysis was used to determine their compatibility with PVC. The implications of these results on PVC stabilization were discussed     

A new approach in the development and testing of antifouling paints without organotin derivatives

Environmental concerns have led to a progressive withdrawal of antifouling paints containing organotin derivatives. Resanbio?, a cooperative research program, plans to develop new antifouling paints that are more compatible with living species. In the first stage, we studied specific acrylic polymers with a variable hydrophilic/hydrophobic balance and, in some cases, pendant hydrolyzable functions. To evaluate the ability of these materials for hydrolysis, biocides release, and erosion, test panels with formulated films were prepared and immersed in sea water. An analytical protocol was established to characterize the polymeric material, to reveal chemical reactions that occur during erosion and antifouling action, and to understand the influence of the resin chemical structure on the paint’s antifouling efficiency. The degradation of these binders was revealed by the appearance of a product resulting from the hydrolysis. This product was identified and quantified by GC-MS. The release of cuprous oxide as model molecule, due to its water solubility and biocide activity, was quantified by inductively coupled plasma. The different processes used are explained and illustrated by an example of an efficient, erodable, antifouling paint following 22 months of immersion.     

The development of novel metal-based combustion catalysts

The performance of a newly developed metal-based combustion reactor is discussed. The heat transfer properties under combustion conditions of a so-called sintered-metal reactor covered with a palladium oxide on silica catalyst have been studied up to 550°C. Also enhancement of the thermal stability of the silica by means of addition of aluminium was investigated. With mixed oxides of silicon and aluminium combustion catalysts have been prepared and they have been shown to exhibit good activity in the combustion of methane.     

改性蛋白质锚定钯催化剂对有机锡烷偶联反应的催化性能研究

制备了以超细二氧化硅为载体的氰乙基化可溶性蛋白质-钯催化剂，研究了它在有机锡烷和酰氯化合物的偶联反应中的催化行为。结果表明，该催化剂对偶联反应具有较高的催化活性和化学选择性，分离容易，可重复使用，用XPS、XRD等方法对催化剂进行了表征，主明催化活性中心质点是金属态的钯。     

有机锡化合物(C6H5)3SnCl的合成及晶体结构

合成了有机锡化合物(C6H5)3SnCl,通过元素分析、红外光谱和核磁共振氢和锡谱对其结构进行了表征。用X-射线单晶衍射测定了该化合物的晶体和分子结构。化合物晶体为三斜晶系,空间群P,īa=9.740(9),b=18.674(17),c=19.010(17),α=105.513(14)°,β=90.036(14)°,γ=90.258(15)°,V=3 332(5)3,Z=8,Dc=1.537 Mg/m3,μ=1.682mm-1,F(000)=1 520,R=0.045 8,wR=0.103 0。锡原子呈畸变四面体构型。     

Improved organotin stabilizers: Continuing health and environmental research

Years of experience and significant research support the use of organotin mercaptides as PVC stabilizers. Safe use of organotin stabilizers involves following Material Safety Data sheet instructions and using adequate engineering controls and/or personal protective equipment. Modifications of stabilizers to develop more efficient formulations continue, Product stewardship includes continued development of data to improve our understanding of the effects of materials. An overview of stabilizer trends in the industry, existing data, and planned health/environmental research is presented.     

The development of structure and microporosity in cellulose carbon

Changes in structure and microporosity of a non-graphitizing cellulose carbon upon heattreatment to 1870 K were followed by electron microscopy, X-Ray measurements, evolved hydrogen analysis and adsorption of carbon dioxide. The 1170 K carbon has a disordered structure containing distorted, defective layer planes which occur singly or in small stacks. Rapid lateral growth of layer planes and improvement in planarity occur on heat treatment to 1670 K and are associated with expulsion of hydrogen. Microporosity is an interconnected network of slit-like pores between layer planes. Layer plane growth above 1670 K causes a collapse of some ultra-micropores to turbostratic spacings resulting in growth of layer stacks and conversion of open micropores to closed micropores. The loss of some ultra-micropores by conversion to turbostratic spacings causes a progressive increase in mean micropore sizes with heat treatment.     

The catalytic activity and defect structure of zinc chromate

Computer simulation techniques are used to develop defect models for the non-stoichiometric spinel with composition Zn_1+xCr_2–xO₄ system. The results are used to provide an interpretation of the variation with composition of the catalytic activity of the monophasic material. We suggest that the increase in the catalytic activity with the Zn/Cr ratio is associated with an increased concentration of oxygen vacancies.     

The structure of organotin oxides playing a key role on the transesterification of dimethyl carbonate with hydrogenated bisphenol A

Transesterification of dimethyl carbonate (DMC) with hydrogenated bisphenol A (HBPA) was studied over various organotin oxides under pressured condition without removal of by-producing methanol. Bu₂SnO displayed higher activities in HBPA conversion and bis-methylcarbonate of hydrogenated bisphenol-A (BMHBPA) synthesis, and HBPA conversion and BMHBPA selectivity reached 97.4% and 84.0%. However, when Ph₂SnO was used as catalyst, HBPA conversion and BMHBPA selectivity decreased to 81.5 and 37.7%. Catalyst steric hindrance significantly influenced HBPA conversion and BMHBPA formation, and π-d interaction between phenyl ring and Sn was unfavorable for the transesterification of HBPA with DMC. Moreover, the catalytic system was further optimized.     

Preparation and characterization of novel organic/inorganic hybrid nanoparticles containing an organotin core and a polystyrene shell

A series of new well‐defined nanoparticles containing an organotin core and a polystyrene shell were obtained by crosslinking of n‐Bu₂SnO with various chain‐length amphiphilic polystyrene‐b‐poly‐(6‐(4‐vinylphenoxy) hexanoic acid. The amphiphilic copolymers were synthesized via reversible addition fragmentation chain transfer polymerization and hydrolysis. The structures of the nanoparticles were studied by the transmission electron microscopy, scanning electron microscopy, and X‐ray photoelectron spectroscopy analysis. Notably, the morphology of the crosslinked copolymer showed individual nanoparticles with regularly spherical shape. And the nanoparticle diameters decreased with increasing number of organotin carboxylate units. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Oxide CMCs: interphase synthesis and novel fibre development

Strategies which have been used in the synthesis of high temperature interphases with debond capability in oxide/oxide systems have been: (i) the formation of layered oxides (β-aluminas or magnetoplumbites) with preferred crystal orientation due to in-situ interface reactions between phases deposited from vapour or liquid precursors and (ii) the deposition on fibre surfaces of complex oxides (vanadates and phosphates, principally of the rare earths) from colloidal precursors or by magnetron sputtering. This paper is primarily concerned with the latter. The constitution and thermal stability of these interphases has been studied with reference to potential fibres and matrices (alumina, YAG and mullite). Included within the program are newly developed single phase mullite fibres and examples of these are also presented.     

核壳结构涂料印花粘合剂及其研究进展

简述了核壳结构涂料印花粘合剂的聚合原理、粘合剂合成过程中的影响因素和表征手段,综述了近年来国内研究现状,并分析了其发展方向。