2种海洋寡糖对大麦种子萌发和生理特性的影响

本研究应用具有不同电荷性的褐藻寡糖(ADO)和壳寡糖(COS)处理大麦种子,探索在相同条件下不同浓度的海洋寡糖对大麦幼苗生长情况及生理特性的影响。生长指标包括苗长、根长、苗重及根重,以及对大麦种子淀粉酶活力和叶绿素含量的影响。试验结果表明:当ADO和COS处理浓度分别为0.5%和0.025%时,大麦的各项生长指标、种子淀粉酶活力及叶绿素含量均达到最大值,与对照组相比显著增加(P<0.05)。2种海洋寡糖均是具有独特生理活性的分子片段,分子量大小相近,但基于2种寡糖分子结构的不同,造成在对大麦的促生长方面存在差异性,为以后2种海洋寡糖的合理开发利用提供了参考。     

Chitosan removes toxic heavy metal ions from cigarette mainstream smoke

This study investigated the removal of heavy metal ions from cigarette mainstream smoke using chitosan. Chitosan of various deacetylation degrees and molecular weights were manually added to cigarette filters in different dosages. The mainstream smoke particulate matter was collected by a Cambridge filter pad, digested by a microwave digestor, and then analyzed for contents of heavy metal ions, including As(III/V), Pb(II), Cd(II), Cr(III/VI) and Ni(II), by graphite furnace atomic absorption spectrometry (GFAAS). The results showed that chitosan had a removal effect on Pb(II), Cd(II), Cr(III/VI) and Ni(II). Of these, the percent removal of Ni(II) was elevated with an increasing dosage of chitosan. Chitosan of a high deace tylation degree exhibited good binding performance toward Cd(II), Cr(III/VI) and Ni(II), though with poor efficiency for Pb(II). Except As(III/V), all the tested metal ions showed similar tendencies in the growing contents with an increasing chitosan molecular weight. Nonetheless, the percent removal of Cr(III/VI) peaked with a chitosan molecular weight of 200 kDa, followed by a dramatic decrease with an increasing chitosan molecular weight. Generally, chitosan had different removal effects on four out of five tested metal ions, and the percent removal of Cd(II), Pb(II), Cr(III/VI) and Ni(II) was approximately 55%, 45%, 50%, and 16%, respectively. In a word, chitosan used in cigarette filter can remove toxic heavy metal ions in the mainstream smoke, improve cigarette safety, and reduce the harm to smokers.     

壳聚糖的脱乙酰度、分子质量和性状对其体外促凝血活性的影响

制备不同脱乙酰度、分子质量的壳聚糖固体粉末和溶液,并利用试管法比较了不同浓度、不同性质及不同状态的样品的体外凝血时间.结果表明:当分子质量相近时,壳聚糖溶液的体外凝血时间随脱乙酰度的增加而减少,脱乙酰度中等的固体粉末具有最强的促凝血能力;当脱乙酰度相近时,只有高分子质量的壳聚糖溶液具有一定的促凝血活性,但固体粉末状态的三种壳聚糖均具有一定的缩短体外凝血时间的能力;同等剂量的壳聚糖溶液和粉末,除了高脱乙酰度、高分子质量的壳聚糖外,其余样品的固体粉末对于缩短体外凝血时间更为有效     

Adsorption of acid fuchsin onto the chitosan–montmorillonite composite

The chitosan–montmorillonite composites (CTS–MMT) were prepared by CTS in combination with Na-type montmorillonite (Na-MMT). The composites were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The effects of initial pH value of the solution, adsorbent dose, the mass ratio of CTS to Na-MMT, the adsorption temperature, and contact time on acid fuchsin (AF) removal efficiency were investigated. The results indicated that the CTS could be successfully intercalated into the interlayers of Na-MMT. With the increase in content of CTS, some of them may be distributed on the surfaces of the clay and the AF removal efficiency can reach 80.2% using CTS–MMT as adsorbent to treatment AF wastewater (the AF concentration 20?mg/L) under the condition of pH, 5; adsorbent dose, 5?g/L; the mass ratio of CTS to Na-MMT, 0.25:1; adsorption temperature, 40°C; and contact time, 90?min. Meanwhile, it was shown that the adsorption processes were better fitted by pseudo-second-order model and the Freundlich model.     

低分子甲壳胺及其衍生物抑制不饱和脂肪酸的氧化作用

通过测定乳化鱼油中不饱和脂肪酸含量和化学发光强度,研究了在５０℃乳化鱼油中,低分子甲壳胺（ＬＭＣＨＳ）和低分子羧甲基甲壳胺硫酸酯（ＣＣＳ）对不饱和脂肪酸氧化的保护作用。测定结果,第６ｄ ＣＣＳ对Ｃ２２：５、Ｃ２２：６氧化抑制率达９６．０３％ 、９２．５０％ ,在第２０ｄ ＬＭＣＨＳ对不饱和脂肪酸Ｃ１６：１、Ｃ１８：１氧化抑制率为６１．０６％ 、６０．０９％ ,对Ｃ１８：３、Ｃ２０：５和Ｃ２２：６氧化抑制率分别为５０．３６％ 、４７．５７％ 、４３．７０％ 。研究表明：ＬＭＣＨＳ和ＣＣＳ对不饱脂肪酸都具有很好的保护作用,效果优于维生素Ｅ。     

Preparations,characterizations and applications of chitosan-based nanoparticles

Chitosan is a natural polysaccharide prepared by the N-deacetylation of chitin. In this paper we have reviewed the methods of preparation of chitosan-based nanoparticles and their pharmaceutical applications. There are five methods of their preparations： emulsion cross-linking, emulsion-droplet coalescence, ionic gelation, reverse micellar method and chemically modified chitosan method. Chitosan nanoparticles are used as carriers for low molecular weight drug, vaccines and DNA. Releasing characteristics, biodistribution and applications are also summarized.     

超细SiO2改性壳聚糖膜的制备、表征及蛋白质分离性能研究

本研究通过先共混沉淀后溶解去除超细SiO₂颗粒(5～10μm)制备改性壳聚糖膜,采用扫描电子显微镜(scanning electron microscope, SEM)观察显示,改性后的壳聚糖膜由微尺度多孔结构和光滑表面结构的非对称结构组成,并且改性前后壳聚糖膜的机械性能没有明显改变。死端过滤实验测试膜通量的结果显示,由于微观凹凸膜结构可增大膜的有效扩散面积,因此改性后壳聚糖膜的水渗透性比未改性壳聚糖膜提高了1.5倍。采用自由扩散法测试溶菌酶(14 kDa)、胰蛋白酶(20 kDa)、胃蛋白酶(34 kDa)、鸡卵清蛋白(43 kDa)和牛血清白蛋白(65 kDa)在壳聚糖膜内的有效扩散系数(effective diffusion coefficients,D_eff),实验结果表明,虽然蛋白质分子量的变化仅为4.6倍,但是改性壳聚糖膜中蛋白质的D_eff变化达330倍,说明壳聚糖膜具有一定的蛋白质选择过滤性能。另一方面,鸡卵清蛋白和牛血清白蛋白的D_eff出现了较为明显的变化,由此推测改性壳聚糖膜传质通...     

具有抑制植物病原真菌活性的含氮、硫、磷壳聚糖衍生物的研究进展

海洋生物体内蕴含着天然活性物质,许多都具有杀菌、杀虫、抗逆、促生长等功能,已成为新农药创制的重要源泉,据此研制新型海洋生物源农药,是海洋生物产业中的一个新领域,也是新型生物农药研发的重要途径。以虾、蟹壳为原料制备的壳聚糖是一种碱性多糖,能够促进植物生长,提高植物抗病、抗逆能力,在农业上受到广泛关注。为提高壳聚糖的应用性,通过改性提高其抑菌性是一个研究热点。本文主要基于本实验室近20年来在壳聚糖衍生化及抑菌活性方面开展的工作,系统地阐述了提高壳聚糖抑菌活性的活性拼接改性策略,即通过在不同位点接枝含氮、含磷、含硫等抑菌活性基团以提高其抑菌活性,分析了其构效关系,为研制新型海洋生物农药提供了理论与技术支撑。     

壳聚糖改性吸附剂的制备及其吸附性能研究

利用壳聚糖与香草醛反应生成的希夫碱壳聚糖(VCG),通过在其一级羟基上进行交联,制备出壳聚糖缩香草醛螯合树脂(S-VCG)。用红外光谱对其结构进行表征,并研究其对重金属离子Cu2 和Pb2 的吸附特性。结果表明:壳聚糖缩香草醛螯合树脂(S-VCG)对Cu2 的平衡吸附时间4h,最大吸附量的pH≈3.2,吸附量约为43.1mg/g,对Pb2 平衡吸附时间5h,最大吸附量的pH≈4,吸附量约为110mg/g。S-VCG具有较强的抗酸性。     

几丁聚糖生物敷料的研究与开发

以几丁聚糖为主要原料,采用理化、正交等试验,研制了几丁聚糖生物敷料配方和生产工艺,并通过体外抗菌、皮肤刺激、皮肤致敏试验,对其细胞毒性及动物药效学等进行药理检验和安全性评价。研究结果表明,使用几丁聚糖生物敷料安全有效,几丁聚糖生物敷料具有良好的生物相容性和天然、广谱抗菌活性,同时还具有明显保护创面、预防感染、促进愈合等生物学功效。