绿藻硫酸多糖SHW及其低分子量片段的结构及抗凝活性研究*

目的 对绿藻多糖SHW及其低分子量片段的结构及抗凝活性进行研究。方法 通过热水提取、强阴离子交换色谱和凝胶渗透色谱,从绿藻硬毛藻中提取分离得到硫酸多糖SHW;通过可控酸解方法制备SHW低分子量片段;采用高效凝胶渗透色谱、高效液相色谱、红外光谱及甲基化方法对多糖结构进行表征;通过活化部分凝血活酶时间、凝血酶时间、凝血酶原时间研究多糖SHW及其低分子量片段体外抗凝血活性。结果 多糖SHW及其低分子量片段主要由阿拉伯糖组成,含有少量半乳糖和氨基葡萄糖;糖链中阿拉伯糖主要以→4)-Arap-(1→和→3,4)Arap-(1→的形式存在,半乳糖以→4)-Galp-(1→存在形式,硫酸根主要位于→4)-Arap-(1→的C-3位。SHW及其低分子量片段A1～A6的分子量分别为492 kDa、200 kDa、170kDa、100kDa、26kDa、14kDa 和10 kDa。SHW 具有较高的抗凝血活性,且其抗凝活性随着其分子量的减少而降低。结论 海藻多糖SHW是一种具有抗凝活性的新颖硫酸多糖,其抗凝活性与分子量密切相关。     

全蝎蛋白抗肿瘤活性研究

目的比较全蝎蛋白超滤分段后各分子量段对肺腺癌细胞A549的抑制作用,筛选有效部分。方法采用蛋白酶酶解法提取全蝎总蛋白,利用80%乙醇沉淀并利用改良Lowry法测定蛋白质含量,再经超滤进行分段、冷冻干燥后通过MTT法研究其对肺腺癌细胞(A549)的抑制作用。结果 80%乙醇沉淀全蝎蛋白具有较高的选择性,其<3 kDa分子量段对A549细胞无抑制作用,3~10 kDa分子量段对A549细胞的抑制作用不明显,>10 kDa分子量段对A549细胞具有显著的抑制作用,IC_(50)=204.7μg·mL~(-1)。结论 80%乙醇沉淀物中蛋白质含量为89.4%;>10 kDa分子量段全蝎蛋白对A549细胞具有显著的抑制作用。     

多肋藻(Costaria costata)多糖的提取分离及理化性质分析

目的 从多肋藻(Costaria costata)中提取分离多糖并对其进行理化性质分析.方法 采用水和2%碳酸钠水溶液于85℃提取多糖,采用高效凝胶渗透色谱法(HPGPC)分析多糖相对分子质量,用核磁共振氢谱(<'1>H-NMR)法分析褐藻胶中M/G比,用高效液相色谱法(HPLC)分析褐藻糖胶单糖组成.结果 从多肋藻中...     

野生与低盐养殖线性硬毛藻(Chaetomorpha linum)多糖的提取分离及其理化性质比较研究△

目的 从野生和低盐养殖线性硬毛藻(Chaetomorpha linum)中提取分离多糖并对其理化性质进行比较分析。方法 以脱脂后的野生和低盐养殖线性硬毛藻为原料,依次经过冷水和热水提取,得到4种粗多糖(WCLC、WCLH、CCLC和CCLH)。运用醋酸纤维素薄膜电泳(CAME)、高效凝胶渗透色谱(HPGPC)、高效液相色谱法(HPLC)、红外光谱法(IR)和核磁共振氢谱(1H-NMR)对其纯度、分子量、单糖组成和结构特征进行分析。结果 粗多糖WCLC、WCLH、CCLC和CCLH得率分别为2.3%,14.3%,3.2%和26.3%;硫酸基含量分别为11.4%,13.0%,9.8%和11.3%;分子量分别为129.5kD,602.3kD,62.85kD和484.2kD。CAME和HPGPC结果显示两种热水提多糖WCLH和CCLH的纯度较高;HPLC分析表明,野生藻和低盐养殖藻多糖中主要含有阿拉伯糖、半乳糖和葡萄糖,但后者中葡萄糖含量较高,WCLC中氨基葡萄糖含量比CCLC的高;1H-NMR分析表明,所有多糖中阿拉伯糖为β-构型,半乳糖为α-构型。结论 野生和低盐养殖线性硬毛藻多糖主要为硫酸阿拉伯半乳聚糖;低盐养殖线性硬毛藻多糖的硫酸基含量低于野生线性硬毛藻,但其葡萄糖含量高于野生线性硬毛藻,表明低盐养殖后,不仅降低其硫酸基含量,而且也会改变多糖中单糖比例。     

不同来源麒麟菜多糖的提取分离和结构比较△

目的 从不同来源麒麟菜中提取分离多糖,分析其理化性质,比较其结构差异。 方法 将6种麒麟菜依次采用冷水和80℃热水提取,提取液经乙醇沉淀、透析及浓缩冻干后获得麒麟菜多糖;分别采用硫酸-苯酚法、Folin-酚法、离子色谱法 (IC)、高效液相色谱法 (HPLC) 等对其总糖、蛋白质、硫酸根含量、分子质量和单糖组成等理化性质进行分析,并采用傅里叶变换红外光谱(FTIR)和核磁共振碳谱(13C-NMR)对其结构进行比较。 结果 从6种麒麟菜中提取获得12种硫酸多糖,其得率在20%~35%之间,其总糖、蛋白质和硫酸根含量分别在55%~75%,2.4%~8.9%和19.9%~35.1%之间,多糖分子量在238~861kDa之间。单糖组成分析表明,各多糖主要由半乳糖以及少量葡萄糖或者木糖组成。EMP-C,EMI-C,EST-C,ESI-C,EDT-C,EST-H,ESI-H,EDT-H主要为ι -卡拉胶,EMP-H,EMI-H,EGH-H,EGH-C主要为κ-卡拉胶。结论 不同来源麒麟菜多糖的结构不同,为不同结构卡拉胶藻源的选择提供了重要参考。     

选育羊栖菜与野生羊栖菜中褐藻胶与褐藻糖胶组成分析

目的比较选育羊栖菜(H.fusiformis)与野生羊栖菜中褐藻胶与褐藻糖胶的组成差异。方法采用高效凝胶渗透色谱法(HPGPC)分析多糖相对分子量,用核磁共振氢谱法测定褐藻胶中G/M比,并用高效离子色谱(HPIC)法分析褐藻糖胶中单糖组成。结果选育羊栖菜和野生羊栖菜中褐藻胶和褐藻糖胶含量分别为29.23%,1.89%和32.18%,2.40%;褐藻胶中G/M比分别为2.62和1.05;褐藻糖胶均含有8种单糖,分别为岩藻糖,半乳糖,甘露糖,葡萄糖醛酸,葡萄糖,木糖,葡萄糖胺和甘露糖醛酸,其摩尔比分别为34.62,18.55,14.17,12.72,10.60,5.79,2.42,1.13及34.76,19.26,10.21,12.70,5.49,10.22,0.70,6.66。结论选育羊栖菜褐藻胶中古罗糖醛酸含量以及褐藻糖胶中葡萄糖,甘露糖和氨基葡萄糖含量均明显高于野生羊栖菜。     

海洋弧菌QY105中褐藻胶寡糖酶OalA的基因克隆、重组表达与性质研究?

目的 褐藻胶寡糖酶可将褐藻胶多糖和寡糖降解为单糖,但现有的褐藻胶寡糖酶数量极少且活力较差。本文旨在从海洋弧菌QY105中克隆寡糖酶OalA的编码基因,重组表达并研究其酶学性质。方法 利用简并PCR和SiteFinding-PCR从海洋弧菌QY105中克隆得到褐藻胶寡糖酶OalA的编码基因,在大肠杆菌中进行重组表达,对重组酶进行分离纯化及酶学性质研究。结果 褐藻胶寡糖酶OalA基因全长2082 bp,编码一条含有693个氨基酸残基的多肽链,理论分子量为79.17 kDa,理论等电点为4.98,属于多糖裂解酶第15家族（PL-15）。重组OalA比活力为9.2 U?mg?1,最适温度30 ℃,在10 ℃的酶活力达到最高酶活的45%,最适pH7.6,在低于30 ℃和pH6~10范围内稳定,偏好降解polyM。结论 OalA具有低温酶的特点,且对polyM具有偏好性,可用于褐藻胶单糖制备、PL-15家族结构与功能相互关系研究等领域。     

褐藻胶寡糖对刀豆蛋白A诱导的急性肝损伤保护作用及机制初探

目的 研究褐藻胶寡糖对刀豆蛋白A (Concanavalin A, ConA)诱导急性肝损伤的保护作用及其可能的作用机制。方法 本实验以分子量为3kDa的甘露糖醛酸寡糖（M-3k）和古罗糖醛酸寡糖（G-3k）为受试样品,通过检测ConA注射后14h血清转氨酶水平及肝组织病理学评估肝脏损伤;通过酶联免疫法(ELISA) 检测TNF-α、IL-6水平;Western Blotting法检测Bcl-2、Bax蛋白表达。结果 与模型组相比,褐藻胶寡糖预防组显著降低了ConA急性肝损伤小鼠血清AST和ALT水平(P＜0.05),且组织病理学观察发现,肝细胞损伤、炎性浸润和凋亡程度减轻;与模型组相比,褐藻胶寡糖预防组显著降低了肝组织匀浆中促炎因子TNF-α、IL-6水平(P＜0.05);褐藻胶寡糖预防组Bcl-2蛋白表达明显高于模型组(P＜0.05),Bax蛋白表达水平明显低于模型组(P＜0.05)。讨论 说明褐藻胶寡糖对ConA诱导小鼠急性肝损伤具有一定保护作用,并且其作用机制可能部分与抑制肝脏炎症反应和干扰凋亡过程有关。     

一种饱和褐藻胶寡糖的制备方法

目的报道一种饱和褐藻胶寡糖的制备方法。方法以褐藻胶为原料,用酸水解法降解,在pH2.85处分级获得均聚古罗糖醛酸片段(PG)和均聚甘露糖醛酸片段(PM),分别在稀盐酸中水解(PG:pH3.8,120℃,3h;PM:pH4,120℃,4h)。水解物经凝胶渗透色谱法分离,获得寡糖组分,反复纯化后,获得系列褐藻胶寡糖。用红外光谱(IR)、核磁共振谱(NMR)、质谱(MS)等方法分析了寡糖的结构。结果褐藻胶经酸水解法降解,分离纯化后获得古罗糖醛酸寡糖二糖到六糖和甘露糖醛酸寡糖二糖到六糖,结构分析表明寡糖保持了原褐藻胶大分子的结构特征。结论本研究为褐藻胶低分子寡糖的制备提供了一种有效、简便的方法。     

霍乱毒素及其B亚单位作为载体联接不同分子量的Vi组成的Vi多糖-蛋白结合物的免疫原性比较

为了比较分子量大小对Vi荚膜多糖-蛋白结合物免疫原性的影响,作者用提纯的弗氏柠檬酸杆菌Vi多糖(分子量约3×10~3kDa)和经超声处理得到的小分子Vi多糖Vi~8(分子量约45kDa)与霍乱毒素(CT)及其B亚单位(CTB)联接,得到三个Vi多糖-蛋白结合物:Vi-CT,Vi-CTB,Vi~s-CTB.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

Lung disease and PKCs

The lung offers a rich opportunity for development of therapeutic strategies focused on isozymes of protein kinase C (PKCs). PKCs are important in many cellular responses in the lung, and existing therapies for pulmonary disorders are inadequate. The lung poses unique challenges as it interfaces with air and blood, contains a pulmonary and systemic circulation, and consists of many cell types. Key structures are bronchial and pulmonary vessels, branching airways, and distal air sacs defined by alveolar walls containing capillaries and interstitial space. The cellular composition of each vessel, airway, and alveolar wall is heterogeneous. Injurious environmental stimuli signal through PKCs and cause a variety of disorders. Edema formation and pulmonary hypertension (PHTN) result from derangements in endothelial, smooth muscle (SM), and/or adventitial fibroblast cell phenotype. Asthma, chronic obstructive pulmonary disease (COPD), and lung cancer are characterized by distinctive pathological changes in airway epithelial, SM, and mucous-generating cells. Acute and chronic pneumonitis and fibrosis occur in the alveolar space and interstitium with type 2 pneumocytes and interstitial fibroblasts/myofibroblasts playing a prominent role. At each site, inflammatory, immune, and vascular progenitor cells contribute to the injury and repair process. Many strategies have been used to investigate PKCs in lung injury. Isolated organ preparations and whole animal studies are powerful approaches especially when genetically engineered mice are used. More analysis of PKC isozymes in normal and diseased human lung tissue and cells is needed to complement this work. Since opposing or counter-regulatory effects of selected PKCs in the same cell or tissue have been found, it may be desirable to target more than one PKC isozyme and potentially in different directions. Because multiple signaling pathways contribute to the key cellular responses important in lung biology, therapeutic strategies targeting PKCs may be more effective if combined with inhibitors of other pathways for additive or synergistic effect. Mechanisms that regulate PKC activity, including phosphorylation and interaction with isozyme-specific binding proteins, are also potential therapeutic targets. Key isotypes of PKC involved in lung pathophysiology are summarized and current and evolving therapeutic approaches to target them are identified.     

Gender-related symptoms and correlates of alcohol dependence among men and women with a lifetime diagnosis of alcohol use disorders

This study explored gender-related symptoms and correlates of alcohol dependence in a crosssectional study of 150 men and 150 women with a lifetime diagnosis of alcohol use disorders (AUD). Participants were recruited in equal numbers from treatment settings, correctional centres and the general community. Standardized measures were used to determine participants' use of substances, history of psychiatric disorders and psychosocial stress, their sensation seeking and family history of substance use and mental health disorders. Multivariate analyses were used to detect patterns of variables associated with gender and the lifetime severity of AUD. Men had a longer history of severe AUD than women. Women had similar levels of alcohol dependence and medical and psychological sequelae as men, despite 6 fewer years of AUD. More women than men had a history of severe psychosocial stress, severe dependence on other substances and antecedent mental health problems, especially mood and anxiety disorders. There were differences in family history of alcohol-related problems approximating same-gender aggregation. The severity of a lifetime AUD was predicted by its earlier age at onset and the occurrence of other disorders, especially anxiety, among both men and women. The limitations in the generalizability of these findings due to sample idiosyncrasies are discussed.     

Biochemical and molecular characterisation of cubozoan protein toxins

Class Cubozoa includes several species of box jellyfish that are harmful to humans. The venoms of box jellyfish are stored and discharged by nematocysts and contain a variety of bioactive proteins that are cytolytic, cytotoxic, inflammatory or lethal. Although cubozoan venoms generally share similar biological activities, the diverse range and severity of effects caused by different species indicate that their venoms vary in protein composition, activity and potency. To date, few individual venom proteins have been thoroughly characterised, however, accumulating evidence suggests that cubozoan jellyfish produce at least one group of homologous bioactive proteins that are labile, basic, haemolytic and similar in molecular mass (42-46 kDa). The novel box jellyfish toxins are also potentially lethal and the cause of cutaneous pain, inflammation and necrosis, similar to that observed in envenomed humans. Secondary structure analysis and remote protein homology predictions suggest that the box jellyfish toxins may act as α-pore-forming toxins. However, more research is required to elucidate their structures and investigate their mechanism(s) of action. The biological, biochemical and molecular characteristics of cubozoan venoms and their bioactive protein components are reviewed, with particular focus on cubozoan cytolysins and the newly emerging family of box jellyfish toxins.     

Dose tolerability of chronically inhaled voriconazole solution in rodents

Invasive pulmonary aspergillosis (IPA) is a fungal disease of the lung associated with high mortality rates in immunosuppressed patients despite treatment. Targeted drug delivery of aqueous voriconazole solutions has been shown in previous studies to produce high tissue and plasma drug concentrations as well as improved survival in a murine model of IPA. In the present study, rats were exposed to 20 min nebulizations of normal saline (control group) or aerosolized aqueous solutions of voriconazole at 15.625 mg (low dose group) or 31.25 mg (high dose group). Peak voriconazole concentrations in rat lung tissue and plasma after 3 days of twice daily dosing in the high dose group were 0.85 ± 0.63 μg/g wet lung weight and 0.58 ± 0.30 μg/mL, with low dose group lung and plasma concentrations of 0.38 ± 0.01 μg/g wet lung weight and 0.09 ± 0.06 μg/mL, respectively. Trough plasma concentrations were low but demonstrated some drug accumulation over 21 days of inhaled voriconazole administered twice daily. Following multiple inhaled doses, statistically significant but clinically irrelevant abnormalities in laboratory values were observed. Histopathology also revealed an increase in the number of alveolar macrophages but without inflammation or ulceration of the airway, interstitial changes, or edema. Inhaled voriconazole was well tolerated in a rat model of drug inhalation.