海因改性N-季铵化壳聚糖衍生物的合成及其抗菌性能

在酸性条件下,以壳聚糖与环氧季铵盐为原料反应得到水溶性良好的产物N-(2-羟丙基三甲基氯化铵)壳聚糖(HTCC),再用实验室自制的环氧海因改性,得到O-羟丙基(5,5-二甲基海因)-N-(2-羟丙基三甲基氯化铵)壳聚糖衍生物(GH-HTCC),用 FTIR、¹H NMR、UV-VIS和EA 等对产物进行表征。抗菌实验结果表明,产物对两种菌种都有一定的抗菌活性,对金黄色葡萄球菌的抗菌活性优于大肠杆菌;GH-HTCC的抗菌活性优于HTCC,并随环氧海因取代度的增加而增强;低浓度的乙二胺四乙酸(EDTA)增强了HTCC和GH-HTCC的抗菌活性,而高浓度的EDTA在一定程度上抑制了二者的抗菌活性。     

O-季铵化低聚壳聚糖芳香醛席夫碱衍生物的制备及其抑菌活性

以低聚壳聚糖为对象,苯甲醛、水杨醛、香草醛为改性试剂,设计合成了一系列O-季铵盐低聚壳聚糖芳香醛席夫碱衍生物。产物元素分析发现其席夫碱取代度接近100%,电位滴定确定产物的季铵盐接枝率在35%左右。抑菌活性研究表明,合成的各种O-季铵盐低聚壳聚糖芳香醛席夫碱衍生物抑菌活性明显增强,活性大小依次为香草醛改性物水杨醛改性物苯甲醛改性物低聚壳聚糖。抑菌活性构效关系分析表明,低聚壳聚糖通过芳香醛席夫碱改性引入了酚羟基抑菌活性中心,但酚羟基的抑菌活性受空间位阻影响较大。     

壳聚糖的季铵化改性及其应用

阐述了壳聚糖季铵化改性的常用改性剂,改性后的壳聚糖理化性能的改善情况及其应用领域。     

季铵化壳聚糖衍生物的合成与表征

以壳聚糖为原料,首先进行壳聚糖的季铵化,随后连接长链饱和脂肪酸,选择癸酸、月桂酸、肉豆蔻酸、棕榈酸和硬脂酸来连接季铵化壳聚糖,使其具有两亲性以成为药物传送的载体。设计并合成了两亲性的季铵化壳聚糖衍生物,并使用红外光谱、核磁共振氢谱和核磁共振碳谱等方法对其化学结构进行表征。实验发现,季铵化程度对脂肪酸连接反应影响较大,分别选择了一步和两步季铵化的壳聚糖与脂肪酸进行反应,以探讨其中的关系。     

季铵化改性壳聚糖的制备及其凝血性能研究

为了对壳聚糖进行化学改性及探究其凝血性能,以来源丰富的壳聚糖为起始原料,通过亲核取代反应,开展季铵化改性,采用紫外-可见光谱、红外光谱及X-射线衍射进行结构表征,并在体外探索其凝血性能。化学结构表征结果表明,季铵化壳聚糖已经成功制备得到;季铵化壳聚糖(50 mg)的体外凝血时间为128.2 s,凝血指数为43.6%,血浆复钙时间为102.1 s,制备得到的季铵化壳聚糖具有较强的促凝血性能。     

O-季铵化改性壳聚糖固载环糊精的制备及其载药性能

对壳聚糖进行O-季铵化改性,并与羧甲基-β-环糊精在均相条件下进行缩合反应,制得O-季铵化壳聚糖固载环糊精(QCSCD),用FTIR、EA和SEM对产物进行表征。以酮洛芬为模型药物,研究其载药及药物释放行为。结果表明,季铵盐基团的引入提高了QCSCD的载药量,为3.97mg/mg,并且改变了QCSCD的pH响应性能。与壳聚糖固载环糊精相反,QCSCD在模拟胃液中的释放速率很快,而在模拟肠液中具有缓释性能。     

季铵型改性壳聚糖的制备及其在兔毛织物抗菌整理中的应用

以三乙胺和环氧氯丙烷为原料,合成醚化剂3-氯-2-羟丙基三乙基氯化铵。以甲壳素为原料通过醚化反应合成了季铵型甲壳素（CCT）,再经脱乙酰得到季铵型阳离子改性壳聚糖（CCTS）。采用红外光谱（FTIR）、核磁碳谱（¹³C NMR）对其化学结构进行了表征,运用黏度法和分光光度法测定了黏均分子量和溶解性等理化性能。采用最小抑菌法对CCTS的抗菌活性进行了测定,得到其对大肠杆菌的最低有效抑菌浓度（MIC）为0.2g/L,优于天然壳聚糖的MIC值。以柠檬酸为交联剂、次磷酸钠为催化剂,用CCTS对兔毛织物进行抑菌整理,考察织物经整理的抑菌效果和耐洗性。经5次洗涤后结果表明,CCTS对大肠杆菌的抑菌率达99.9%以上,抑菌率高于CCT和天然壳聚糖,是一种针对动物毛织物良好的天然高分子长效抑菌整理剂。     

壳聚糖及其衍生物的抗菌活性研究进展

壳聚糖及其衍生物具有无毒、可生物降解、生物相容和抗菌性等许多优点,作为新型抗菌剂已引起越来越多的关注,但壳聚糖的溶解性差限制了其应用。为有效解决这一问题,研究人员通过化学改性提高其水溶性和抗菌性。本文综述了近年来壳聚糖及其衍生物抗菌活性的研究情况,并就其可能的抗菌机理及其影响抗菌活性的因素进行讨论。     

壳聚糖缩糠醛Schiff碱合成研究

文章由壳聚糖与糠醛缩合反应合成了一种Schiff碱,通过L934正交实验法,对合成的反应温度、反应时间、pH和反应物的配比进行了优化。得到了制备的最佳条件:pH=9,反应物配比n(壳聚糖结构单元):n(糠醛)=1:4,反应温度70℃,反应时间3h。此时,壳聚糖缩糠醛Schiff碱的缩合产率最大为85.47%。合成的Schiff碱是一种双烯体,可用于双烯合成反应。并通过FTIR、UV对Schiff碱的结构进行了表征。     

壳聚糖季铵化衍生物结构表征及特性研究

采用壳聚糖(CTS)与2,3-环氧丙基三甲基氯化铵(GTA)制备了不同取代度的水溶性壳聚糖季铵盐(HACC),通过红外、扫描电镜对壳聚糖、壳聚糖季铵盐结构进行表征,同时测试了壳聚糖季铵盐的水溶性、表面张力.结果表明:取代主要发生在壳聚糖的氨基上,改性后产物外观与粒度有很大变化;壳聚糖季铵化改性产物具有比壳聚糖更优良的水溶性、表面活性,且随着取代度的增加而提高.     

木质素糠醛改性甲阶酚醛树脂的合成

采用木质素和糠醛改性普通甲阶酚醛树脂。运用正交实验法得到木质素糠醛改性甲阶酚醛树脂的最佳反应条件,通过IR,DSC,TG分析和压缩性能测试对产物的热性能和力学性能进行了研究。结果表明,在苯酚100g,木质素40g,甲醛116.54g,糠醛34.28g,反应温度85℃,反应时间3h,体系pH值9的条件下得到的改性甲阶酚醛树脂固含量70%～80%,黏度850～1000mPa.s(25℃),热分解温度为258℃,与普通甲阶酚醛树脂(263℃)相比,耐热性稍差。所制备的改性酚醛塑料的压缩强度为1.07MPa,比普通酚醛塑料(0.73MPa)高,木质素和糠醛的引入提高了泡沫塑料的韧性。     

水溶性氮杂环修饰小檗碱衍生物的合成

为了提高小檗碱的水溶性,增加其在体内的吸收和转运效率,以小檗碱为初始原料,经高温脱去C(9)位甲基,然后与二溴烷烃进行单边溴烷基化反应,再与苯并咪唑、1,2,4-三氮唑和吡唑经亲核取代反应制得了一系列氮杂环修饰的小檗碱衍生物（4～6）。除了化合物6a,所得衍生物均为新化合物,其结构经核磁氢谱/碳谱（¹H NMR/¹³C NMR）、电喷雾质谱[MS（ESI）]多重表征确认。随后,利用紫外分光光度法测定了部分衍生物在水中的溶解度,结果显示奇数链长烷基取代1,2,4-三氮唑的引入使小檗碱在水中的溶解度大幅度提升。其中,1,3-亚丙基桥连的1,2,4-三氮唑小檗碱衍生物的水溶性高达13.87mg/mL,是小檗碱的12倍,因此它是潜在的具有更高生物利用度的小檗碱药物前体。     

新型壳聚糖季铵盐抗菌剂的合成及其性能

先用两步法合成了无O-甲基化 N,N,N-三甲基壳聚糖季铵盐（TMC）,再通过相转移催化合成了N,N,N-三甲基O-辛基壳聚糖季铵盐（TMOC）,用 FTIR、1H NMR、EA、TG 等方法对产物进行表征,并研究其抗菌性能。结果表明,TMOC在pH值为5.5的抗菌活性优于pH值为7.2的抗菌活性;TMOC对革兰阳性菌S. aureus的抗菌活性比革兰阴性菌E. coli强。在不影响水溶性的前提下,O-烷基化改性能有效提高壳聚糖季铵盐的抗菌活性,并且抗菌活性随着O-烷基化度的提高而提高。研究结果为壳聚糖基抗菌剂的改性和制备提供了依据。     

Synthesis and characterization of chitosan derivatives carrying galactose residues

A series of water‐soluble chitosan derivatives, carrying galactose residues, were synthesized by using an alternative method in which the galactose groups were introduced into amino groups of the derivatives. First, hydroxyethyl chitosan (HECS) and hydroxypropyl chitosan (HPCS) were synthesized under alkaline conditions by using chitosan and propylene or chitosan and ClCH₂CH₂OH as the starting materials, respectively. Then lactobionic acid was added into the systems so as to form galactosylated HECS (Gal‐HECS) and galactosylated HPCS (Gal‐HPCS) with substitution degrees of 53 and 47%, respectively. Lactosaminated HPCS (Lac‐HPCS) and Lactosaminated HECS (Lac‐HECS) were obtained with substitution degrees of 42 and 38%, respectively, by the reductive amination of the mixtures of lactose and HECS or lactose and HPCS with potassium borohydride present in the reaction. The chemical structures of new chitosan derivatives were characterized by FTIR, ¹H NMR, ¹³C NMR, and elemental analysis. Some physical properties were also analyzed by wide angle X‐ray diffraction (WAXD) and differential scanning calorimetry (DSC). The novel chitosan derivatives carrying galactose residues may be used as additives for hepatic targeting delivery. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2161–2167, 2005     

Synthesis and adsorption properties of metal ions of novel azacrown ether crosslinked chitosan

Azacrown ether chitosan (CTSC) was synthesized by the reaction of chitosan with N‐allyl benzo 15‐crown‐5 crown ether. Azacrown ether crosslinked chitosan (CCTSC) was prepared by the crosslinked reaction of CTSC and epichlorodydrin. Their structures were confirmed by infrared spectral analysis and X‐ray diffraction analysis. The adsorption properties of CTSC and CCTSC for metal ions were also investigated. The experimental results showed that the two chitosan derivatives not only had a good capacity to adsorb Pd²⁺ and Ag⁺ but also was highly selective for Pd²⁺ and Ag⁺ in the coexistence system containing other metal ions. At 20°C ± 1°C and pH = 4, the adsorption capacity of CTSC and CCTSC for Pd²⁺ was 186.1 and 173.1 mg/g, respectively; and for Ag⁺ was 90.2 and 56.5 mg/g, respectively. The selectivity coefficients were K = 6.99, K = ∞, K = 35.38, K = ∞ for CTSC and K = 10.66, K = ∞, K = 85.45, K = ∞ for CCTSC. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2705–2709, 2006     

O-一氯均三嗪-N,N,N-三甲基壳聚糖的合成及其在羊毛织物抗菌中的应用

采用甲醛甲酸法合成N,N,N-三甲基壳聚糖（TMC）,再用三氯均三嗪与TMC反应,合成带有可与纤维反应的水溶性O-一氯均三嗪-N,N,N-三甲基壳聚糖（MCT-TMC）。采用FTIR、XRD、热重和元素分析等对产物进行表征,并测试其抗菌性能。将产物对羊毛织物进行抗菌整理,研究整理时间和浓度等工艺条件对抗菌性能的影响。结果表明,TMC和MCT-TMC具有较好的抗菌性能;将其用于羊毛织物抗菌整理的最佳工艺条件为：整理时间60min,整理浓度分别为3%（owf）和2%（owf）;经TMC整理的织物对E.coli和S.aureus的抑菌率分别为97.8%和99.2%,MCT-TMC整理的织物对E.coli和S.aureus的抑菌率分别为98.6%和99.8%。MCT-TMC整理羊毛织物的耐洗涤性能比TMC有显著提高,洗涤后抑菌率仍达到90%以上。     

对双胍基苯甲酰化壳聚糖盐酸盐的制备及其抗菌活性研究

在盐酸溶液中,对氨基苯甲酸与双氰胺反应合成了中间体对双胍基苯甲酸盐酸盐;该中间体再与氯化亚砜反应得双胍基苯甲酰氯。后者在甲磺酸体系中与壳聚糖进行酰化反应制得对双胍基苯甲酰壳聚糖盐酸盐。考察了酰化时间、温度及反应物投料比等对壳聚糖衍生物取代度的影响,并采用UV,IR,1HNMR对产物进行了表征。抗菌实验表明,该产物对大肠杆菌、金黄色葡萄球菌最低抑菌浓度分别为0.016和0.008 mg/mL,其抗菌活性优于壳聚糖和对双胍基苯甲酸盐酸盐,且随浓度的增大而增强。     

Synthesis and adsorption properties for metal ions of crosslinked chitosan acetate crown ethers

Two novel chitosan derivatives—crosslinked chitosan dibenzo‐16‐c‐5 acetate crown ether (CCTS‐1) and crosslinked chitosan 3,5‐di‐tert‐butyl dibenzo‐14‐c‐4 diacetate crown ether (CCTS‐2)—were synthesized by the reaction of crosslinked chitosan with dibenzo‐16‐c‐5 chloracetate crown ether and 3,5‐di‐tert‐butyl dibenzo‐14‐c‐4 dichloracetate crown ether with the intent of forming polymers that could be used in hazardous waste remediation as toxic metal‐binding agents in aqueous environments. Their structures were confirmed with elemental analysis, infrared spectral analysis, and X‐ray diffraction analysis. In the infrared spectra of CCTS‐1 and CCTS‐2, the characteristic peaks of aromatic backbone vibration appeared at 1595 cm⁻¹ and 1500 cm⁻¹; the intensity of the N H and O H stretching vibration in the region of 3150–3200 cm⁻¹ decreased greatly. The X‐ray diffraction analysis showed that the peak at 2θ = 20° decreased greatly in CCTS‐1 and CCTS‐2. The adsorption and selectivity properties of CCTS‐1 and CCTS‐2 for Pb²⁺, Cu²⁺, Cr³⁺, and Ni²⁺ were studied. Experimental results showed that the two crosslinked chitosan derivatives had not only good adsorption capacities for Pb²⁺, Cu²⁺, but also high selectivity for Pb²⁺, Cu²⁺ in the coexistence of Ni²⁺. For aqueous systems containing Pb²⁺, Ni²⁺, or Cu²⁺, Ni²⁺, CCTS‐1 only adsorbed Pb²⁺ or Cu²⁺. For aqueous systems containing Pb²⁺, Cr²⁺ and Ni²⁺, CCTS‐2 had high adsorption and selectivity properties for Pb²⁺. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2069–2074, 1999     

Synthesis and properties of chitosan‐modified poly(vinyl acetate)

A redox initiator, cerium ammonium nitrate, was used to initiate the graft copolymerization of vinyl acetate (VAc) onto the chitosan chain in a dispersion polymerization at 60°C. With an addition of 0.5–7.5 g of chitosan based on 50 g of VAc, the monomer conversion was found to be between 70 and 80% after 2 h of reaction. The grafting efficiency increased with the amount of chitosan added; yet, the grafting ratio increased slightly and then decreased. After the reaction, a stable dispersion system was observed and the surface of the latex particles was found to be rich in chitosan. All the experimental results indicated that the chitosan molecules not only took part in the graft copolymerization, but also served as a surfactant, providing the stability of the dispersion particles. If the dispersion aqueous solution was oven‐dried, a particulate membrane was formed. The experimental results indicated that the incorporation of poly(vinyl acetate) to the chitosan chains increased the toughness and decreased the water absorption of the chitosan material. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3057–3063, 2002