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甲壳胺-明胶共混物的研究 总被引:24,自引:0,他引:24
甲壳胺 明胶共混物的研究莫秀梅(华东理工大学高分子材料系上海200237)关键词甲壳素,明胶,共混物,红外光谱甲壳胺是甲壳素的脱乙酰基产物,即将甲壳素C2上的乙酰基脱去变成氨基,因此在甲壳胺分子侧链上增加了一个活泼氨基,从而易于化学改性或共混改性.... 相似文献
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2,3-二取代-4-(IH-l,2,4-三唑-l-基)-5-苯基氢基噻吩的合成及生物活性研究 总被引:5,自引:0,他引:5
合成了九个以噻吩为母体环的含三唑环的化合物——2,3-二取代-4-(1H-1, 2,4.三唑-1-基)-5-苯基氨基噻吩(2a-2i),并测定了2a的晶体结构.晶体为三斜 晶系,P-1空间群,晶胞参数为:a=0.79816(15)nm,b=1.00259(13)nm,c=1. 4478(4)nm,a=100.326(16)°,β=94.69(2)°,r=106.083(9)°,V=1.0845 (4)nm~3,z=2,D_c=1.396 g/cm~3.初步生物活性表明所有目标化合物杀菌活 性较低,有一定的植物生长调节活性. 相似文献
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2,4,6-三〔芳基氨基)-1,3,5-三嗪衍生物的合成方法和微波效应研究 总被引:2,自引:0,他引:2
用碳酸氢钠作扑酸剂,将芳香胺和氰尿酰氯在1,4-二氧六环中回流状态下反 应合成了7个2,4,6-三(芳基氨基)-1,3,5-三嗪衍生物,其中6个是新化合物. 与已有文献报道的方法相比,条件温和,易于操作,收率高.所合成化合物的结构 通过元素分析,FAB-MS,IR确定.在二氧六环:DMF为10:3(V:V)的混合溶剂中, 研究了在微波照射下和常规加热下反应速率的差异.结果表明,微波加热比常规加 热下的反应速率至少高10倍以上. 相似文献
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由新型联苯手性骨架(R)-( )-2-氨基-2′-羟基-6,6′-二甲基-1,1′-联苯la,(R)-( )-2-氨基-2′-羟基-4,4′,6,6′-四甲基-1,1′-联苯1b与不同取代基的水杨醛反应合成了9个新型席夫碱配体2a-2i,化合物的结构用核磁共振以及高分辨质谱进行表征.其中(R)-( )-2-氨基-2′-羟基-6,6′-二甲基-1,1′-联苯和3,5-二溴水杨醛衍生得到的席夫碱配体2g与Ti(O′Pr) 生成的配合物催化不对称2-甲氧基丙烯与对硝基苯甲醛的Hetero-ene反应,在-10℃反应3h时获得了最高为79?的反应产物. 相似文献
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N-取代苯基-N'-(1,3,4-噻二唑-2-基)脲类化合物的合成与生物活性 总被引:5,自引:1,他引:5
通过酰基叠氮化物与2-氨基噻二唑或5-氨基-2-巯基噻二唑反应,合成了10个新的N-取代苯基-N'-(1,3,4-噻二唑-2-基)脲,用核磁共振氢谱、红外光谱和元素分析确证了它们的结构,初步的生测活性试验表明,部分目标化合物2c,2d具有良好的细胞分裂素活性. 相似文献
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Crystal transition from hydrated chitosan and chitosan/monocarboxylic acid complex to anhydrous chitosan investigated by X‐ray diffraction
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Philip‐Kunio Naito Yu Ogawa Satoshi Kimura Tadahisa Iwata Masahisa Wada 《Journal of Polymer Science.Polymer Physics》2015,53(15):1065-1069
We have studied the crystal transition behaviors from hydrated chitosan to anhydrous chitosan by X‐ray diffraction analyses. Hydrated chitosan prepared by deacetylation of crustacean α‐chitin was subjected to the two conversion methods, hydrothermal treatment and high‐humidity treatment via chitosan/monocarboxylic acid complex. The transition by hydrothermal treatment progressed with increasing treatment temperature and time, and the rapid transition occurred above 200 °C. Chitosan/acetic acid complex and chitosan/formic acid complex were prepared by immersing hydrated chitosan in acid solution. The transition from chitosan/acetic acid complex to anhydrous chitosan in high relative humidity condition proceeded with increasing temperature and was complete at 80 °C for 1 h, whereas chitosan/formic acid complex did not convert to anhydrous chitosan under the same conditions. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1065–1069 相似文献
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对壳聚糖进行液态均相络合反应制得壳聚糖铜配合物,IR、UV、元素分析及热重分析等检测证实了壳聚糖铜配合物中配位键的存在,且显示壳聚糖在形成配位结构后存在有利于降解的优势构象。以H2O2对壳聚糖-Cu(Ⅱ)络合物及壳聚糖进行氧化降解,考察降解过程中粘度的变化及降解产物分子量分布,在相同的降解条件下,壳聚糖铜配合物的降解速度明显高于壳聚糖,降解产物分子量分布较壳聚糖直接降解窄,结果进一步证明壳聚糖铜配合物中存在有利于降解的优势结构,同时证明以金属离子Cu(Ⅱ)对壳聚 相似文献
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由硫脲壳聚糖和微量的AgNO3反应得到硫脲壳聚糖Ag+配合物。 通过红外光谱对其结构进行了表征。 研究了壳聚糖、硫脲壳聚糖、硫脲壳聚糖-Ag+配合物及AgNO3对大肠杆菌和金黄葡萄球菌的抑菌活性,并测定了其最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。 结果表明,硫脲壳聚糖-Ag+配合物的抑菌活性强于壳聚糖和硫脲壳聚糖,且其MIC和MBC均为100 mg/L(游离Ag+含量为0.032 mg/L),低于AgNO3的MIC和MBC(均为120 mg/L)。 相似文献
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Tan Vui Nguyen Thi Thu Ha Nguyen San-Lang Wang Thi Phuong Khanh Vo Anh Dzung Nguyen 《Research on Chemical Intermediates》2017,43(6):3527-3537
Chitosan nanoparticles were prepared from chitosan with various molecular weights by tripolyphosphate (TPP) ionic gelation combined with a spray drying method. The morphologies and characteristics of chitosan nanoparticles were determined by TEM, FE-SEM and from their mean sizes and zeta potentials. The effect of chitosan molecular weight (130, 276, 760 and 1200 cPs) and size of spray dryer nozzle (4.0, 5.5 and 7.0 µm) on mean size, size distribution and zeta potential values of chitosan nanoparticles was investigated. The results showed that the mean size of chitosan nanoparticles was in the range of 166–1230 nm and the zeta potential value ranged from 34.9 to 59 mV, depending on the molecular weight of chitosan and size of the spray dryer nozzles. The lower the molecular weight of chitosan, the smaller the size of the chitosan nanoparticles and the higher the zeta potential. A test for the antibacterial activity of chitosan nanoparticles (only) and a chitosan nanoparticle–amoxicillin complex against Streptococcus pneumoniae was also conducted. The results indicated that a smaller chitosan nanoparticle and higher zeta potential showed higher antibacterial activity. The chitosan nanoparticle–amoxicillin complex resulted in improved antibacterial activity as compared to amoxicillin and chitosan nanopaticles alone. Using a chitosan nanoparticle–amoxicillin complex could reduce by three times the dosage of amoxicillin while still completely inhibiting S. pneumoniae. 相似文献
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水溶性量子点的制备及其与壳聚糖衍生物的自组装 总被引:2,自引:0,他引:2
以3-巯基丙酸(HS-CH2CH2COOH)为稳定剂, 制备了水溶性的碲化镉(CdTe)量子点(QDs), 考察了制备条件对QDs荧光性能的影响及CdTe QDs与壳聚糖及叶酸和聚乙二醇改性的壳聚糖的自组装. 研究发现, 壳聚糖及改性壳聚糖与QDs的复合物荧光强度相对纯的CdTe QDs明显增强, 且QDs被包裹在内核, 复合粒子呈明显的核/壳结构. 改性壳聚糖/QDs复合物较小且尺寸分布更为均一. 相似文献
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This paper describes the preparation of a biocompatible electrostatic chitosan/pyridine-3,5-di-carboxylic acid (CH-PyCA) complex which is formed by the protonation (NH+ 3) of chitosan and deprotonation (COO?) of pyridine-3,5-di-carboxylic acid in an acidic medium under mild conditions. The crystalline and structural properties of prepared CH-PyCA complex were evaluated by UV, IR XRD and 1H-NMR spectroscopic studies. Thermal behavior of the complex was evaluated by differential scanning calorimetry (DSC) and thermogravimetry (TG). Antimicrobial activities examined against gram-positive bacteria (Listeria monocytogenes) and gram-negative bacteria (Escherichia coli) by agar diffusion plate method in the obtained CH-PyCA complex, were found to be much better than free chitosan and pyridine compounds and the obtained results indicate that the inhibitory effects of chitosan complex is dependent on the molecular weight, ionic strength, pH, and the degree of deacetylation of chitosan. The results show that the CH-PyCA complex might be a promising candidate for novel antimicrobial agents for biomedical applications. 相似文献
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以柠檬酸三钠、11-氨基十一烷、聚乙二醇400为碳源,利用微波法制备了碳量子点,将其与壳聚糖反应,制备出碳量子点/壳聚糖复合物。采用荧光、紫外、红外光谱等对碳量子点和碳量子点/壳聚糖复合物进行表征,探究了温度、时间、缓冲溶液及pH对体系荧光强度的影响。在pH 7.6的硼酸—硼砂缓冲介质中,槲皮素可使碳量子点/壳聚糖复合物发生荧光猝灭,其猝灭程度与槲皮素浓度呈良好的线性关系,据此建立了碳量子点/壳聚糖荧光猝灭法测定槲皮素的新方法,方法线性范围为4~40μmol/L,相关系数为0.9940,检出限为0.5μmol/L。方法已应用于测定本地甜瓜中槲皮素的含量。 相似文献
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Guy Jobin Gilles Grondin Geneviève Couture Carole Beaulieu 《Microscopy and microanalysis》2005,11(2):154-165
Spores of the biocontrol agent, Streptomyces melanosporofaciens EF-76, were entrapped by complex coacervation in beads composed of a macromolecular complex (MC) of chitosan and polyphosphate. A proportion of spores entrapped in beads survived the entrapment procedure as shown by treating spores from chitosan beads with a dye allowing the differentiation of live and dead cells. The spore-loaded chitosan beads could be digested by a chitosanase, suggesting that, once introduced in soil, the beads would be degraded to release the biocontrol agent. Spore-loaded beads were examined by optical and scanning electron microscopy because the release of the biological agent depends on the spore distribution in the chitosan beads. The microscopic examination revealed that the beads had a porous surface and contained a network of inner microfibrils. Spores were entrapped in both the chitosan microfibrils and the bead lacuna. 相似文献