Polylactones. 13. Transesterification of Poly(L-Lactide) with Poly(Glycoude), Poly(β-Propio-Lactone), and Poly[ε -Caprolactone)

Homogeneous blends of poly(L-lactide) (M _n = 30 000 to 40 000) and poly(β-propiolactone) or poly(ε-caprolactone) were prepared in solution. The solvent-free blends were subjected to transesterification catalyzed by means of methyl triflate, triflic acid, boron trifluoride, or tributyltin methoxide at 100 or 150°C. At 100°C, transesterification was barely detectable even after 96 h. When poly(β-propiolactone) was used as the reactant at 150°C, degradation was faster than transesterification regardless of the catalyst. The same negative result was obtained for heterogeneous blends of poly(L-lactide) and poly(glycolide). In the case of poly(ε-caprolactone), copolyesters with slightly blocky sequences were obtained with tributyltin methoxide as catalyst, whereas the acidic catalysts caused rapid degradation. The copolyesters were characterized by means of ¹H-NMR spectroscopy with regard to their molar composition, by means of ¹³C-NMR spectroscopy with regard to their sequences, and by means of differential scanning calorimetry with regard to crystallinity.     

Pentacyanoferrates(II) on the surface of organomodified silica gel: The matrix effect

Pentacyanoferrate(II) absorbed on a silica gel surface previously modified with 3-aminopropyl and 3-imidazolylpropyl groups were characterized by¹³C MAS/NMR, FT-IR, Mössbauer spectroscopy, and cyclic voltammetry. FT-IR and¹³C MAS/NMR data indicated that the pentacyanoferrate(II) complex is bonded to the surface by the nitrogen atom of the functional group. The differences in the isomeric shifts, the quandrupole splittings and the midpoint potentials of the adsorbed complexes in comparison with the model complexes were attributed to the matrix polar effect—i.e., the interaction of the complex with polar groups on the silica surface.     

5-氟尿嘧啶自旋标记衍生物的合成及其抗肿瘤活性研究

将4种稳定氮氧自由基引入5-氟尿嘧啶,合成了10个新的5-氟尿嘧啶(Fu)自旋标记衍生物2a-8.经元素分析、IR、UV、MS和ESR确定了其组成和结构.化合物对KB、HCT-8和A 2780细胞毒性实验结果表明,化合物2a和3a的抗癌活性高于5-Fu,与HCFU的活性相当.     

氟尿嘧啶自旋标记衍生物的合成与抗肿瘤活性

稳定氮氧自由基作为某些抗癌药物的载体,不仅能提高药物对癌细胞的选择性,而且为借助电子自旋共振(ESR)技术研究药物的作用机理和代谢提供了一种新手段。在前文中,我们报道了几种5-氟尿嘧啶的自旋标记衍生物。作为这一工作的继续,本文报道一系列新的氟尿嘧啶自旋标记衍生物10_(a—c)、11_(a—c)和12_(a—c)的合成及其抗肿瘤活性的研究。     

Synthesis of Andrographolide Cyclophosphate Derivatives and Their Antitumor Activities

A series of cyclophosphate andrographolide derivatives were synthesized from andrographolide, the cytotoxic constituent of the plant Andrographis paniculata. The derivative (P_R, P′_S)‐5 and (P_S, P′_S)‐6 were synthesized and the proposed mechanism for their formation was discussed. The structures of all compounds were elucidated by IR, NMR, MS (ESI), and HR‐MS. The stereochemistry of 6 was confirmed by X‐ray analysis. All the derivatives were tested for antitumor activity in vitro, and some of them showed good results.     

Syntheses, Crystal Structures and Antitumor Activities of Two Nicotinamides

Two nicotinamides have been synthesized by coupling aromatic amines with equimolar quantities of substituted nicotinic acids. Their structures have been determined by X-ray single-crystal diffraction. Compound 1, 6-chloro-N-(4-fluorophenyl)nicotinamide, crystallizes in the triclinic space group Pī with a = 4.2188(8) , b = 5.0687(10), c = 25.956(5), α = 86.38(3), β = 87.75(3), γ = 83.20(3)°, V = 549.75(19) 3 and Z = 2. Compound 2, N-(quinolin-3-yl)nico- tinamide, crystallizes in the monoclinic space group P21 with a = 8.5100(17), b = 6.4230(13), c = 11.620(2) , β = 110.39(3)°, V = 595.3(2) 3 and Z = 2. The cytotoxic activities of the two nicotinamides against five human tumor cell lines were tested in vitro. The results indicated that they showed a wide range of antitumor activities.     

Preparation and characterization of polyimide/mesoporous silica hybrid nanocomposites based on water-soluble poly(amic acid) ammonium salt

Recently, mesoporous silica was blended with polyimide to develop low dielectric constant (k) materials with improving mechanical and thermal properties of polyimide by utilizing both the nanoporous structure and silica framework. However, even the use of mesoporous silica did not show a significant decrease of k due to the phase segregation in between polyimide and the mesoporous silica materials. In this work, we attempted to prepare polyimide/mesoporous silica hybrid nanocomposites having relatively good phase mixing behavior by utilizing polyimide synthesized from a water soluble poly(amic acid) ammonium salt, which lead to low k up to 2.45. The thermal properties of polyimide were improved by adding mesoporous silicas. For this work, we have fabricated mesoporous silicas through surfactant-templated condensation of tetraethyl orthosilicate (TEOS). Pyromellitic dianhydride (PMDA)-4,4′-oxydianiline (ODA) polyimide was prepared from poly(amic acid) ammonium salt, which had been obtained by incorporating triethylamine (TEA) into PMDA-ODA poly(amic acid) in dimethylacetamide (DMAc), followed by thermal imidization.     

N,N-二(2-氯乙基)果糖基磷酰胺酯的合成及其抗肿瘤活性研究

糖基磷酸酯类化合物,特别是葡萄糖基磷酸酯类化合物的合成及其生物活性的研究已有报道。1988年Hayachi等发现葡萄糖基磷酸酯衍生物具有抗肿瘤、抗病毒等生物活性,可用作医用药物。但果糖基磷酰胺酯及其衍生物的合成与抗肿瘤活性尚未见文献报道。为研究糖基磷酰胺酯的合成方法并筛选出有抗肿瘤活性的化合物,以期发现新型、高效、低毒、有应     

Syntheses,Structures and Antitumor Activities of Tri(o-bromobenzyl)tin Diethyldithiocarbamate and Tri(m-fluorobenzyl)tin Pyrrolidine Dithiocarbamate

Tri(o-bromobenzyl)tin diethyldithiocarbamate(1) and tri(m-fluorobenzyl)tin pyrrolidine dithiocarbamate(2) have been synthesized and characterized by elemental analysis, IR spectroscopy, NMR(~1 H, ¹³C and ¹¹⁹Sn), thermogravimetric analysis and single-crystal X-ray diffraction. The two complexes crystallize in the triclinic system space group P1. For complex 1, a = 0.9770(1), b = 1.1011(1), c = 1.4583(1) nm, α = 78.431(1)°, β = 86.307(1)°, γ = 69.712(1)°, V = 1.4417(2) nm^3, Z = 2, Dc = 1.790 g/cm^3, m(Mo Kα) = 52.04 cm–1, F(000) = 756, R = 0.0434 and wR = 0.0593. For complex 2, a = 0.7055(1), b = 1.3349(3), c = 1.3782(3) nm, α = 89.216(2)°, β = 82.044(2)°, γ = 84.637(2)°, V = 1.2799(5) nm^3, Z = 2, Dc = 1.537 g/cm^3, m(Mo Kα) = 11.98 cm^–1, F(000) = 596, R = 0.0313 and wR = 0.0333. The two complexes represent mononuclear structures with five-coordinated [SnC3S2] cores forming a distorted trigonal bipyramid. The quantum chemical calculations of 1 and 2 have been investigated. The antitumor activity shows that 1 and 2 have higher activities than cisplatinum against Colo205, HepG2, MCF-7, Hela and H460 cell line in vitro.     

水溶性铜卟啉配合物的合成、与DNA的相互作用及抗肿瘤活性

合成了3种水溶性铜卟啉配合物,分别为水溶性含溴铜卟啉(CuP-1)及其溴取代衍生物(CuP-2、CuP-3),并采用核磁氢谱、元素分析、质谱等手段进行了结构表征。利用紫外光谱法、EB-DNA荧光淬灭法、粘度法以及圆二色谱法等光谱法研究了CuP-1、CuP-2和CuP-3与小牛胸腺DNA(CT-DNA)的相互作用。采用噻唑兰(MTT)法,以体外培养的宫颈癌细胞(Hela)和乳腺癌细胞(MDA)为测试细胞株对CuP-1~CuP-3的抗肿瘤活性进行检测。人成纤维细胞(L929)作为正常细胞系。光谱法实验结果表明,CuP-1以插入的方式与CT-DNA相互作用,而CuP-2和CuP-3与CT-DNA以沟面结合的方式相互作用,且CuP-1与CT-DNA的结合能力优于CuP-2和CuP-3。体外抗癌活性实验结果表明,CuP-1~CuP-3对Hela和MDA均有体外抑制细胞增殖作用,呈时间、剂量依赖关系,并且CuP-1的体外抗肿瘤活性明显优于CuP-2、CuP-3。     

Silica Gel-Immobilized 5-aminoisophthalohydrazide: A novel sorbent for solid phase extraction of Cu,Zn and Pb from natural water samples

A novel silica sorbent, silica gel-immobilized 5-aminoisophthalohydrazide (SiO₂-APH), was prepared by the condensation of 3-chloropropyl-functionalized silica gel with 5-aminoisophthalohydrazide (APH) derived from dimethyl 5-aminoisophthalate as a starting material and used for separation and preconcentration of Cu, Zn, and Pb metals in water samples using Flame Atomic Absorption Spectrometry (FAAS). The characterization of the new sorbent was carried out by Elemental Analysis, Thermogravimetric Analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR). Important analytical parameters including as pH, amount of sorbent, type and amount of eluting solvent, sample volume, vortex and ultrasonic bath time, matrix ions that effect the developed SiO₂-APH-solid phase extraction (SPE) method were investigated and optimum parameters were detected. Recoveries of examined metals were obtained as 98% for Cu and Pb and 101% for Zn. The relative standard deviation (RSD, n = 8) of Cu, Zn and Pb metals were 3.2, 2.8 and 1.6%, respectively. Limit of detections (LODs) (n = 10) were found as 2.7 μg L⁻¹ for Cu, 7.4 μg L⁻¹ for Zn and 3.5 μg L⁻¹ for Pb μg L⁻¹. The accuracy of the new method was assessed by analyzing of TMDA-51.4 and TMDA-70.2 certified reference materials. The results obtained for metals were in a good agreement with certified values. Addition/recovery test was applied to the real well, river, dam and stream water samples to check the accuracy of the method. The results showed that the developed SiO₂-APH-SPE method can be effectively used as an alternative method for determination of Cu, Zn, and Pb metals in water samples.     

Stereocontrolled Syntheses of (4S, 5R)- and (4S, 5S)-Dihydroxy-N-Decanoic Acid-4-Lactones Via Biochemical Methods

(4S-5R)- and (4S-5S)-dihydroxy-n-decanoic acid-4-lactones have been synthesized in a stereocontrolled manner by a chemomicrobiological approach.     

有机锡5-甲基/氨基-1H-四唑乙酸酯的合成、结构与抗肿瘤活性

通过5-甲基/氨基-1H-四唑乙酸与（R₃Sn）₂O（R为苯基或正丁基）及三环己基氢氧化锡的反应,合成了5个三有机锡5-甲基/氨基-1H-四唑乙酸酯。通过核磁,红外及X射线单晶衍射分析,对这些化合物进行了详细的结构表征。结果表明,这些化合物往往通过分子间的Sn…N作用形成配位高分子。初步的生物活性测试表明,这些配合物对Hela和A549细胞具有明显的体外细胞毒性。     

Structure and catalytic activity of metal complexes fixed on carriers. Hydrodehalogenation of p-bromotoluene with chemically bonded hydrogen,catalyzed by immobilized rhodium(II) complexes

The structure of Rh(II) complexes with vigorous ligands immobilized on -aminopropyl-containing silicagel (-AMPS) and polymers containing 3(5)-methyl-pyrazole and imidazole groups, was investigated. It was shown by IR spectroscopy that the ligand surroundings are maintained after application only for the Rh(II) acetate complex. For the acetonitrile and hexafluoroacetylacetonate complexes there is a replacement of the ligands by amino groups of the carrier. [Rh₂(O₂CCH₃)₄] is significantly more active than other metal complexes immobilized on -AMPS in the hydrodehalogenation of p-bromotoluene by transfer of hydrogen from NaBH₄ and propanol-2.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 65–70, January, 1992.     

Syntheses of 1,3,4-Thia（oxa）diazole-substituted Pyrazole Derivatives and Their Fungicidal Activities

A series of 1,3,4-oxadiazole or 1.3.4-thiadiazole-substituted pyrazole derivatives were synthesized from 4-pyrazole formhydrazide; their biological activities were studied. The structures of all the new compounds were confirmed by means of spectroscopic methods and microanalyses. The preliminary bioassay results indicate that some compounds of them have a good fungicidal activity against Phoma asparagi and Physalospora piricola Nose.     

Effect of Physical and Chemical Adsorption of Ethylene on the Kinetics of Its Oxidation by Palladium(II) Chloride on Silica Gel

An equation has been obtained to take into account adsorption in the kinetics of metal complex reactions occurring on a surface via an equilibrium intermediate compound formed between the complex and the substrate. The physical and chemical adsorption of ethylene is determined in the kinetics of its oxidation by palladium(II) chloride on silica gel at 300 K.     

2,3—二取代—5—氟脲嘧啶的合成及其抗肿瘤活性研究

以相转移催化法或在无水体系中合成了十个未见文献报道了２，３－二取代５－氟脲嘧啶化合物，它们的结构经ＩＲ、＾ＨＮＭＲ元素分析或ＭＳ等确证。其中有些化合物具有一定的抗肿瘤活性。     

5-氟尿嘧啶卟啉锰/锌配合物的合成、光电性质及抗癌活性

合成了新型5-氟尿嘧啶修饰的自由卟啉5-(2-(5-氟尿嘧啶-3-基)乙氧基苯基)-10,15,20-三苯基卟啉(L)及其锰配合物(MnL)和锌配合物(ZnL)。通过紫外-可见光谱、红外光谱、核磁共振氢谱及高分辨质谱等手段进行了结构表征。研究了它们的荧光性质和电化学性质;应用标准磺酰罗丹明B法(SRB法)测试了目标化合物对人肺癌细胞株A549、人肝癌细胞株Bel-7402和人结肠癌细胞株HCT-8生长的抑制活性。结果表明:相同实验条件下,不同金属离子对配合物的荧光强度存在较大影响:锌配合物具有荧光猝灭的性质,而锰配合物未能观察到明显的荧光发射光谱;与自由卟啉和锌配合物相比,锰配合物除卟啉环发生氧化还原反应外,Mn~(2+)自身也发生了氧化还原反应;抗癌活性测试显示锰配合物较其他2种化合物有较好的抗癌活性。     

1-(Z)-[2-(三芳基锡基)乙烯基]环戊醇及其衍生物的合成及生物活性

合成了１４种新的（Ｚ）－［２－（三芳基锡基）乙烯基］环戊醇类有机锡化合物,通过元素分析,ＩＲ、＾１Ｈ ＮＭＲ 对所合成的化合物进行了表征,结果表明（Ｚ）－［２－（三芳基锡基）乙烯基］环戊醇类有机锡化合物中乙烯式双键为顺式构型,分子内羟基与锡原子发生配位,形成五元螯合环。生物活性测定结果表明,二卤化物在抗癌,免疫及受体作用等方面具有优良的活性。     

乙二醇甲醚中电解锡电解液直接水解制备纳米SnO2

采用锡金属为阳极，在无隔膜电解槽中，电化学溶解锡于乙二醇甲醚中制备得到纳米SnO2前驱体Sn(OCH2CH2OCH3)4，将电解液直接水解经溶胶-凝胶法制备纳米SnO2，前驱体通过拉曼和红外光谱进行表征.纳米SnO2采用X射线粉末衍射(XRD)和透射电子显微镜(TEM)进行表征.实验表明,电解合成的Sn(OCH2CH2OCH3)4能够溶解于乙醇中, 适宜作为溶胶-凝胶(sol-gel)法制备纳米SnO2的原料，制得的纳米SnO2经600 ℃煅烧后呈球形单分散结构，晶型为四方锡石型, 比表面为62.58 m2·g－1，平均粒径在(10.0±0.4) nm左右.产率为89.3％，电流效率为86.9％.