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1.
海胆多糖的化学与药理研究进展   总被引:1,自引:0,他引:1       下载免费PDF全文
海胆是1种低等的海洋无脊椎动物,属于棘皮动物门(Echinodermata)海胆纲(Echinoidea),具有较高的营养价值和潜在的药用价值。本文重点综述了来源于海胆的岩藻聚糖、半乳聚糖、杂多糖、糖胺聚糖和中性葡聚糖的单糖组成、糖苷键类型、硫酸根位置与数量、重复单元等一系列结构特征,及其抗凝与抗血栓、免疫调节与抗肿瘤作用等生物活性,并对海胆多糖的化学与生物活性进行了讨论与展望。  相似文献
2.
一种紫贻贝水提多糖的理化性质和结构分析   总被引:1,自引:0,他引:1  
目的从紫贻贝中提取和分离纯化多糖,并对其基本理化性质和结构进行分析,为紫贻贝多糖活性研究提供基础。方法将紫贻贝鲜肉制成丙酮粉后,经60℃热水提取,去核酸和采用Sepharcryl S-300凝胶层析分离得到了一种水溶性多糖组分(HWS)。采用硫酸-苯酚法、Folin-酚法、柱前衍生高效液相色谱法和高效凝胶渗透色谱法分别对HWS的总糖含量、蛋白含量、单糖组成、相对分子质量进行了测定,并通过甲基化和气质联用(GC/MS)分析、红外光谱(FT-IR)、核磁共振(NMR)技术对HWS的结构进行了分析。结果 HWS是以(1→4)-α-D-Glcp为主链,含有少量的→2,4)-Glcp-(1→和→6)-β-Glc-(1→分支的葡聚糖,平均每6个主链糖残基含有1个分支。结论采用60℃热水提取和凝胶柱层析分离得到紫贻贝多糖,通过多种化学分析及现代仪器分析技术确定了HWS的结构,为紫贻贝多糖活性的深入研究提供了参考和借鉴。  相似文献
3.
牛蒡子中牛蒡子苷元的分离及结构表征   总被引:1,自引:0,他引:1  
目的:从牛蒡子中分离纯化出有效成分,并对其分子结构进行鉴定与表征。方法:采用醇提酸解法提取,分离出粗品,经过对粗品进行脱脂、结晶处理,得到无色棱状晶体。采用紫外光谱(UV)、红外光谱(FTIR)、质谱(MS)、氢谱(H-NMR)、碳谱(C-NMR)及单晶衍射对该有效成分进行组成和分子结构的鉴定与表征。结果:从牛蒡子粗粉中经提取分离,得到结晶,提取率为4.46%,显色反应及波谱分析均显示为木脂素类化合物。结论:该有效成分鉴定为牛蒡子苷元,即(3R,4R)-4-[(3,4-二甲氧基苯基)甲基]二氢-3-[(4-羟基-3-甲氧基苯基)甲基]-2(3H)-呋喃酮,分子式为C21H24O6。  相似文献
4.
A proteinase, named BmooMPalpha-I, from the venom of Bothrops moojeni, was purified by DEAE-Sephacel, Sephadex G-75 and heparin-agarose column chromatography. The enzyme was purified to homogeneity as judged by its migration profile in SDS-PAGE stained with coomassie blue, and showed a molecular mass of about 24.5 kDa. Its complete cDNA was obtained by RT-PCR and the 615 bp codified for a mature protein of 205 amino acid residues. The multiple alignment of its deduced amino acid sequence and those of other snake venom metalloproteinases showed a high structural similarly, mainly among class P-IB proteases. The enzyme cleaves the Aalpha-chain of fibrinogen first, followed by the Bbeta-chain, and shows no effects on the gamma-chain. On fibrin, the enzyme hydrolyzed only the beta-chain, leaving the gamma-dimer apparently untouched. It was devoid of phospholipase A(2), hemorrhagic and thrombin-like activities. Like many venom enzymes, it is stable at pH values between 4 and 10 and stable at 70 degrees C for 15 min. The inhibitory effects of EDTA on the fibrinogenolytic activity suggest that BmooMPalpha-I is a metalloproteinase and inhibition by beta-mercaptoethanol revealed the important role of the disulfide bonds in the stabilization of the native structure. Aprotinin and benzamidine, specific serine proteinase inhibitors, had no effect on BmooMPalpha-I activity. Since the BmooMPalpha-I enzyme was found to cause defibrinogenation when administered i.p. on mice, it is expected that it may be of medical interest as a therapeutic agent in the treatment and prevention of arterial thrombosis.  相似文献
5.
真鱿软骨硫酸软骨素的提取、鉴定及结构分析   总被引:1,自引:0,他引:1       下载免费PDF全文
目的 采用酶解提取法,从真鱿软骨中提取1种新型的硫酸软骨素,对其化学结构进行研究。方法 采用酶解法、氯化十六烷基吡啶(CPC)沉淀法从鱿鱼软骨中提取纯化硫酸软骨素,通过PMP柱前衍生液相色谱法、聚丙烯酰氨凝胶电泳(PAGE)、核磁共振波谱法(NMR)和液质联用分析(HPLC-MS),对硫酸软骨素的化学结构进行分析。结果 使用木瓜蛋白酶酶解鱿鱼软骨,乙酸缓冲液在料液比为1:30(g/mL)条件下,硫酸软骨素的提取率最高,蛋白质残留最低,经过CPC纯化,得到了纯度高达99.5%的硫酸软骨素。由PAGE电泳可以看出其分子量很大且能够被硫酸软骨素ABC酶酶解。单糖分析表明,鱿鱼硫酸软骨素主要由乙酰氨基半乳糖、葡萄糖醛酸以及少量的葡萄糖组成。硫酸软骨素ABC酶将其水解为聚合度2-18的偶数糖,采用HPLC-MS分析,可以得到所有寡糖的全指纹谱图。结合1H-NMR分析可知,从真鱿软骨提取出来的硫酸软骨素主要含有6-单硫取代的硫酸软骨素C二糖单元和4,6-双硫取代硫酸软骨素E二糖单元,其所占比例分别为60.3%和39.7%,硫酸根含量为22.3%,是属于高硫的硫酸软骨素。结论 从真鱿软骨中提取出了具有高硫酸根含量的硫酸软骨素组分,可用于开发保健食品和海洋药物。  相似文献
6.
The ability of amylodextrin (a linear dextrin) to act as a complexing agent or as a carrier for solid dispersion was evaluated. Blends of amylodextrin with diazepam or prednisolone were freeze-dried and kneaded at elevated temperatures, respectively. The products were analyzed by DSC, X-ray diffractometry, and FTIR spectroscopy. Complex formation with amylodextrin by freeze-drying was found not to occur for diazepam but for prednisolone at a molar ratio of 1 to 1. The freeze-dried product of diazepam with amylodextrin proved to be a solid dispersion. Solid dispersions were formed by both wet (with ethanol) and dry kneading at elevated temperatures of low-melting drugs such as lidocain, diazepam, and methyl-PABA with amylodextrin. No solid dispersions were obtained for high-melting drugs such as prednisolone and salicylic acid. The results point to the formation of solid dispersions by a melting mechanism during the process of kneading at elevated temperatures of low-melting drugs with amylodextrin.  相似文献
7.
The linear dextrin amylodextrin was prepared by enzymatic hydrolysis from waxy maize. Four metastable amylodextrins were prepared by complexation with different volatile organic compounds. All products showed partial dissolution into water at room temperature, because of dissolution of molecules with a lower DP. X-ray diffractometry revealed a helical conformation with six glucose units per turn for amylodextrin and metastable amylodextrins prepared with small molecules, and a helical conformation with seven glucose units per turn for metastable amylodextrins prepared with larger molecules. All metastable amylodextrins showed a helix with reduced distance between two turns as compared to amylodextrin. Metastable amylose, prepared from Amylose V, showed a helical conformation again with a reduced distance between two turns compared to Amylose V. FTIR analysis indicated a more flexible conformation for Amylose V and metastable amylose than for the amylodextrins.  相似文献
8.
Introduction: New frontiers in nanomedicine are moving towards the research of new biomaterials. Apoferritin (APO), is a uniform regular self-assemblies nano-sized protein with excellent biocompatibility and a unique structure that affords it the ability to stabilize small active molecules in its inner core.

Areas covered: APO can be loaded by applying a passive process (mainly used for ions and metals) or by a unique formulative approach based on disassemby/reassembly process. In this article, we aim to organize the experimental evidence provided by a number of studies on the loading, release and targeting. Attention is initially focused on the most investigated antineoplastic drug and contrast agents up to the most recent application in gene therapy.

Expert opinion: Various preclinical studies have demonstrated that APO improved the potency and selectivity of some chemotherapeutics. However, in order to translate the use of APO into therapy, some issues must be solved, especially regarding the reproducibility of the loading protocol used, the optimization of nanocarrier characterization, detailed understanding of the final structure of loaded APO, and the real mechanism and timing of drug release.  相似文献

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