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111.
Chalinulasterol (1) a new chlorinated sterol disulfate was isolated from the Caribbean sponge Chalinula molitba. Its structure was elucidated using mass spectrometry and NMR experiments. The possible role of chalinulasterol as modulator of the PXR nuclear receptor was investigated but, in spite of the close structural relationship with the PXR agonist solomonsterol A (2), it showed no activity. The structural requirements for the PXR nuclear receptor activity were discussed.  相似文献   
112.
Na Gao  Mingyi Wu  Shao Liu  Wu Lian  Zi Li  Jinhua Zhao 《Marine drugs》2012,10(8):1647-1661
Fucosylated chondroitin sulfate (FuCS), a kind of complex glycosaminoglycan from sea cucumber, has potent anticoagulant activity. In order to understand the relationship between structures and activity, the depolymerized FuCS (dFuCS) was chosen to prepare its derivates by selective substitution at OH groups. Its O-acylation was carried out in a homogeneous way using carboxylic acid anhydrides. The structures of O-acylated derivatives were characterized by NMR. The results indicated that the 4-O-sulfated fucose residues may be easier to be acylated than the other ones in the sulfated fucose branches. But the O-acylation was always accompanied by the β-elimination, and the degree of elimination was higher as that of acylation was higher. The results of clotting assay indicated that the effect of partial O-acylation of the dFuCS on their anticoagulant potency was not significant and the O-acylation of 2-OH groups of 4-O-sulfated fucose units did not affect the anticoagulant activity.  相似文献   
113.
钾素对马铃薯的生长发育、结薯、薯块膨大和干物质的积累具有十分重要的作用。凉山州马铃薯主产区土壤普遍缺钾少磷,试验选用马铃薯品种凉薯97,研究在凉山州不同地区不同海拔高度施用硫酸钾对马铃薯生物性状的影响,结果表明:马铃薯施用一定量的硫酸钾能适当延长生育期、显著增产、增加薯块干物质和淀粉含量。667 m2施用硫酸钾15 kg的平均全生育期比对照增加2 d;667 m2施用硫酸钾10 kg的平均产量最高,达到1 819 kg,较对照高28.26%,差异达极显著水平;施用硫酸钾对提高干物质、淀粉含量有一定的作用,综合考虑产量、品质、效益等因素,667 m2硫酸钾施用量以5.0~10.0 kg为宜。  相似文献   
114.
通过静态单因子急性毒性试验,表明硫酸铜对泥鳅水花和夏花苗种的24,48,96 h的半致死浓度(LC50)分别为0.702,0.587,0.509 mg/L和1.810,1.412,1.270 mg/L,安全浓度分别为0.05,0.13 mg/L;硫酸亚铁对泥鳅水花和夏花苗种的24,48,96 h的半致死浓度(LC50)分别为12.472,9.819,8.297 mg/L和24.876,19.024,16.833 mg/L,安全浓度分别为0.83,1.68 mg/L;戊二醛对泥鳅水花和夏花苗种的24,48,96 h的半致死浓度(LC50)分别为13.286,13.264,12.319 mg/L和45.101,42.701,40.547 mg/L,安全浓度分别为1.23,4.05 mg/L;氧化钙对泥鳅水花和夏花苗种的24,48,96 h的半致死浓度(LC50)分别为102.609,102.299,98.815 mg/L和119.345,117.288,114.305 mg/L,安全浓度分别为9.88,11.43 mg/L。在泥鳅苗种阶段,药物敏感性由大到小依次为硫酸铜、硫酸亚铁、戊二醛、氧化钙。  相似文献   
115.
硫酸锌浸种对马铃薯品质的影响   总被引:1,自引:0,他引:1  
在盆栽条件下,以马铃薯(Solanum tuberosumL.)早大白为材料,以浸种方式施用不同浓度硫酸锌,通过比较马铃薯块茎内各种品质指标含量的高低,研究硫酸锌对马铃薯品质的影响。结果表明:适宜浓度的硫酸锌溶液能够改善马铃薯块茎的品质,其中以浓度为0.06%的硫酸锌溶液对提高马铃薯质量的效果好,其可提高马铃薯淀粉和可溶性蛋白质蛋白含量,而浓度为0.12%的硫酸锌溶液则显著提高了还原糖含量,不利于马铃薯品质提高。  相似文献   
116.
目的 观察柚皮素单硫酸酯钠盐(SNMS)对血栓形成和血小板聚集的影响.方法 将30只SD大鼠随机分为5组:SNMS1组、SNMS2组、血栓通组、肝素组和对照组,每组6只,麻醉大鼠,静脉注射药物后,用血栓生成仪观察大鼠颈动脉血栓形成情况;取兔血与药物孵育5min,凝血酶(500 U/L)作用1 min后,用全血血小板聚集...  相似文献   
117.
硫酸锰浸种对马铃薯品质的影响   总被引:1,自引:0,他引:1  
在盆栽条件下,以马铃薯(Solanum tuberosum L.)“早大白”为材料,以浸种方式施用不同浓度硫酸锰,通过比较马铃薯块茎内各种品质指标含量的高低,研究硫酸锰对马铃薯品质的影响.结果表明:适宜浓度的硫酸锰溶液浸种处理能够改善马铃薯块茎品质,其中以浓度为0.16%的硫酸锰溶液的效果好,可提高马铃薯淀粉和维生素C...  相似文献   
118.
Land conversion is considered an effective measure to ensure national food security in China, but little information is available on the quality of low productivity soils, in particular those in acid sulfate soil regions. In our study, acid sulfate paddy soils were divided into soils with high, medium and low levels based on local rice productivity, and 60 soil samples were collected for analysis. Twenty soil variables including physical, chemical and biochemical properties were determined. Those variables that were significantly different between the high, medium and low productivity soils were selected for principal component analysis, and microbial biomass carbon (MBC), total nitrogen (TN), available silicon (ASi), pH and available zinc (AZn) were retained in the minimum data set (MDS). After scoring the MDS variables, they were integrated to calculate a soil quality index (SQI), and the high, medium and low productivity paddy soils received mean SQI scores of 0.95, 0.83 and 0.60, respectively. Low productivity paddy soils showed worse soil quality, and a large discrepancy was observed between the low and high productivity paddy soils. Lower MBC, TN, ASi, pH and available K (AK) were considered as the primary limiting factors. Additionally, all the soil samples collected were rich in available P and AZn, but deficient in AK and ASi. The results suggest that soil AK and ASi deficiencies were the main limiting factors for all the studied acid sulfate paddy soil regions. The application of K and Si on a national basis and other sustainable management approaches are suggested to improve rice productivity, especially for low productivity paddy soils. Our results indicated that there is a large potential for increasing productivity and producing more cereals in acid sulfate paddy soil regions.  相似文献   
119.
As single superphosphate availability decreases due to closure of aging manufacturing plants increasing attention is being paid to alternative phosphorus (P) and sulfur (S) sources. This glasshouse study, conducted under non-leaching conditions was undertaken to evaluate the S supplying capacity of gypsum, S bentonite, elemental S (ES) and a range of P containing fertilizers and those where ES was added as a coating or incorporated. The magnitude of crop response in terms of shoot biomass to applied S fertilizer sources followed the order of sulfates > powdered ES > coated/incorporated ES > S/bentonite. These results indicate that fertilizers containing a mixture of sulfate and micronized ES (<75 µm), either incorporated within the granule or coated onto the fertilizer are agronomically effective. The results also suggest that local S coating of finished fertilizers is a feasible alternative to S incorporation undertaken at a central fertilizer plant.  相似文献   
120.
为确定农业硫酸镁产品指标,通过收集分析农业用硫酸镁企业标准及产品田间肥效试验数据,开展样品检测等。结果表明:筛选镁(Mg)、硼(B)、铁(Fe)、水不溶物、pH、水分、汞(Hg)、砷(As)、镉(Cd)、铅(Pb)、铬(Cr)为农业用硫酸镁产品指标,并确定其指标值分别为镁8.5%、硼0.3%、铁0.2%、水不溶物1.0%、pH3.0~7.0、水分含量≤7.0%、Hg含量≤5 mg·kg~(-1)、As含量≤10 mg·kg~(-1)、Cd含量≤10 mg·kg~(-1)、Pb含量≤50mg·kg~(-1)、Cr含量≤50mg·kg~(-1)。  相似文献   
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