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91.
92.
A new lathyrane diterpene (1), an unreported spectroscopic data lathyrane diterpenene (2), and two known analaogues (3 and 4) have been isolated from Euphorbia prolifera. Their structures were elucidated as (12E,2S,3S,4R,5R,6S,9S,11S,15R)-3-butyryloxy-5,15-diacetoxy-6,17-epoxylathyra- 12-en-14-one (1), (12E,2S,3S,4R,5R,6S,9S,11S,15R)-3-propionyloxy-5,15-diacetoxy-6,17- epoxylathyra-12-en-14-one (2), (12E,2S,3S,4R,5R,6S,9S,11S,15R)-3-benzoyloxy-5,15-diacetoxy -6,17-epoxylathyra-12-en-14-one (3), and 15-O-acetyl-17-hydroxyjolkinol (4) by spectroscopic methods (IR, ESIMS, HR-ESIMS, NMR, and X-ray crystallography). The inhibitory activities on LPS-induced NO production of these diterpenes were evaluated and compounds 1, 3 and 4 showed inhibitory effects. 相似文献
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Anna E. Karagianni Ronan Kapetanovic Bruce C. McGorumDavid A. Hume Scott R. Pirie 《Veterinary immunology and immunopathology》2013
Alveolar macrophages (AMs) constitute the first line of defence in the lung of all species, playing a crucial role in the regulation of immune responses to inhaled pathogens. A detailed understanding of the function and phenotype of AMs is a necessary pre-requisite to both elucidating their role in preventing opportunistic bacterial colonisation of the lower respiratory tract and developing appropriate preventative strategies. The purpose of the study was to characterise this important innate immune cell at the tissue level by making functional and phenotypic comparisons with peritoneal macrophages (PMs). We hypothesised that the tissue of origin determines a unique phenotype of AMs, which may constitute an appropriate therapeutic target for certain equine respiratory diseases. Macrophages isolated from the lung and the peritoneal cavity of 9 horses were stimulated with various toll like receptor (TLR) ligands and the production of nitrite, tumour necrosis factor alpha (TNFα), interleukin (IL) 10 and indoleamine 2,3-dioxygenase (IDO) were measured by the Griess reaction and enzyme linked immunosorbent assay (ELISA) and/or quantitative polymerase chain reaction, respectively. Cells were also compared on the basis of phagocytic-capacity and the expression of several cell surface markers. AMs, but not PMs, demonstrated increased TNFα release following stimulation with LPS, polyinosinic polycytidylic acid (Poly IC) and heat-killed Salmonella typhinurium and increased TNFα and IDO mRNA expression when stimulated with LPS. AMs showed high expression of the specific macrophage markers cluster of differentiation (CD) 14, CD163 and TLR4, whereas PMs showed high expression of TLR4 only. AMs, but not PMs, demonstrated efficient phagocytic activity. Our results demonstrate that AMs are more active than PMs when stimulated with various pro-inflammatory ligands, thus supporting the importance of the local microenvironment in the activation status of the macrophage. This information provides a valuable knowledge base on which to improve our understanding of the role of macrophages and their microenvironment in equine innate immunity. 相似文献
96.
阿氏节杆菌(Arthrobacter arilaitensis)菌株DA-1是一株氨氮降解细菌,且在有氧及厌氧条件下均具有反硝化作用.通过对该菌的厌氧反硝化条件进行优化,考察了碳源、C/N、温度和初始pH对其反硝化作用的影响.结果表明,乙酸钠为最佳的反硝化碳源,当C/N为10∶1、温度为30℃、初始pH为7.0时,A.arilaitensis DA-1能获得最高的反硝化效率,在该条件下,向硝酸盐模拟污水(NO3--N浓度为25mg/L)中接入2%(V/V)的A.arilaitensis DA-1菌剂,经过48 h的静置培养,N03--N的去除量达到了20.13 mg/L,而此时NO2--N积累浓度仅为0.56 mg/L. 相似文献
97.
一氧化氮信号途径参与草地早熟禾耐镉机制的研究 总被引:1,自引:0,他引:1
为探究信号分子一氧化氮(Nitric Oxide,NO)对镉(Cadmium,Cd)胁迫下草地早熟禾(Poa pratensis)的调控机理,揭示草地早熟禾耐镉机理,本试验采取根施1000 μmol·L-1氯化镉(Cadmium chloride hemidihydrate,CdCl2·2.5H2O)及叶面喷施NO合成酶抑制剂(L-硝基精氨酸甲酯(L-NAME))、硝酸还原酶抑制剂(钨酸钠(Tungstate))、NO清除剂(4-羧基苯-4,4,5,5-四甲基咪唑-1-氧-3-氧化物(cPTIO))处理草地早熟禾叶片,研究不同处理对草地早熟禾幼苗叶片生长及抗氧化酶活性、光合色素含量、丙二醛(Malondialdehyde,MDA)、游离脯氨酸、内源NO含量的影响。研究发现,镉胁迫下草地早熟禾内源NO含量增加,添加一氧化氮清除剂、一氧化氮合酶抑制剂、硝酸还原酶抑制剂可增加超氧化物歧化酶(Superoxide Dismutase,SOD)、过氧化氢酶(Catalase,CAT)、抗坏血酸过氧化物酶(Ascorbate peroxidase,APX)活性,降低过氧化物酶(Peroxidase,POD)活性,增加叶绿素a、叶绿素b、类胡萝卜素、丙二醛含量,降低脯氨酸(Proline,Pro)含量、叶片相对含水量(Relative Water Content,RWC)和干物质量(Dry matter content)。结果表明,一氧化氮合酶途径可能是早熟禾合成NO的主要途径,内源NO可通过调节抗氧化酶活性、光合色素含量、游离脯氨酸含量等途径缓解镉胁迫。 相似文献
98.
The extraction of earth alkaline and alkali metals (Ca, Mg, K, Na), heavy metals (Mn, Fe, Cu, Zn, Cd, Pb) and Al by 1 M NH4NO3 and 0.5 M NH4Cl was compared for soil samples (texture: silt loam, clay loam) with a wide range of pH(CaCl2) and organic carbon (OC) from a forest area in W Germany. For each of these elements, close and highly significant correlations could be observed between the results from both methods in organic and mineral soil horizons. The contents of the base cations were almost convertible one‐to‐one. However, for all heavy metals NH4Cl extracted clearly larger amounts, which was mainly due to their tendency to form soluble chloro complexes with chloride ions from the NH4Cl solution. This tendency is very distinct in the case of Cd, Pb, and Fe, but also influences the results of Mn and Zn. In the case of Cd and Mn, and to a lower degree also in the case of Pb, Fe, and Zn, the effect of the chloro complexes shows a significant pH dependency. Especially for Cd, but also for Pb, Fe, Mn, Zn, the agreement between both methods increased, when pH(CaCl2) values and/or contents of OC were taken into account. In comparison to NH4Cl, NH4NO3 proved to be chemically less reactive and, thus, more suitable for the extraction of comparable fractions of mobile heavy metals. Since both methods lead to similar and closely correlated results with regard to base cations and Al, the use of NH4NO3 is also recommended for the extraction of mobile/exchangeable alkali, earth alkaline, and Al ions in soils and for the estimation of their contribution to the effective cation‐exchange capacity (CEC). Consequently, we suggest to determine the mobile/exchangeable fraction of all elements using the NH4NO3 method. However, the applicability of the NH4NO3 method to other soils still needs to be investigated. 相似文献
99.
本研究旨在通过高效液相色谱-质谱联用(LC-MS)和高效液相色谱(HPLC)技术对沙冬青种子总黄酮主要活性成分进行分析及含量测定,并探索沙冬青种子总黄酮对小鼠免疫功能的影响。采用LC-MS分析沙冬青种子总黄酮主要活性成分,在HPLC优化条件下用标准品对主要活性成分的含量进行测定;采用MTT法和ELISA试剂盒检测沙冬青种子总黄酮对小鼠脾淋巴细胞增殖和IL-2、IL-4生成的影响,以及总黄酮对肝脏KCs细胞的增殖和NO、NOS含量的影响;运用定量溶血分光光度法和血清溶血素HC50测定法检测不同浓度沙冬青种子总黄酮对小鼠抗体生成细胞和血清溶血素的影响。结果显示,沙冬青种子总黄酮中主要活性成分为芒柄花素、7,3'-二羟基-4'-甲氧基黄酮、黄豆黄素和穗花杉双黄酮,其中,芒柄花素含量高达52.48%,其次为7,3'-二羟基-4'-甲氧基黄酮,含量为11.20%。在2.5~100 μg/mL总黄酮作用下,沙冬青种子总黄酮对脾淋巴细胞的增殖和细胞因子的产生具有明显的促进作用,尤其在20 μg/mL时脾淋巴细胞增殖率和IL-2的分泌量分别高达217.62%和159.661 pg/mL,与空白对照组相比差异极显著(P<0.01);在40 μg/mL时,脾淋巴细胞IL-4的分泌量高达149.274 pg/mL,极显著高于空白对照组(P<0.01)。沙冬青种子总黄酮对KCs细胞的增殖及NO和NOS分泌也具有明显促进作用,在60 μg/mL时,与空白对照组相比,KCs细胞增殖率达67.77%,NO和NOS的分泌量分别达180.106和29.942 μmol/L(P<0.01)。此外,沙冬青种子总黄酮能明显促进小鼠体内抗体生成细胞和血清溶血素含量的增加。综上表明,沙冬青种子总黄酮主要活性成分为芒柄花素和7,3'-二羟基-4'-甲氧基黄酮。沙冬青种子总黄酮对小鼠免疫活性细胞的增殖、相关免疫细胞因子和抗体的产生与释放等都具有显著的促进作用。 相似文献
100.
不同水稻品种对NO-3 同化差异的比较 总被引:13,自引:1,他引:12
采用水培方法测定了不同形态氮素下 4个品种水稻 (汕优 63、扬稻 6号、泗优 917、农垦 57) 的生长量及其水稻苗期硝酸还原酶活性 (NRA) 和谷氨酰胺合成酶活性 (GSA)。结果表明, 1mmol·L-1 NH 4 培养下, 水稻生长无明显差异, 而 1mmol·L-1 NO-3 培养 28d后, 各品种水稻生长差异显著, 其中, 扬稻 6号生长最优, 农垦 57最差; 籼稻体内的NRA和GSA比粳稻更高, 其中籼稻叶片的NRA比粳稻高出 58 7%, GSA高出 34 6%, 籼稻根系GSA是粳稻根系的 3 2倍, 说明籼稻对NO-3 的吸收利用优于粳稻。 相似文献