共查询到20条相似文献,搜索用时 78 毫秒
1.
全氟化合物是环境中一种新型的持久性有机污染物.近年来,随着全氟化合物的广泛使用,其环境污染问题日益受到人们关注.因此,有必要对其环境行为和检测方法进行研究.综述了全氟化合物在水体、沉积物、大气中的污染现状,总结了关于全氟化合物的采集技术、前处理技术以及检测方法的研究进展. 相似文献
2.
3.
4.
5.
6.
7.
8.
4-色满酮芳环Mannich碱类化合物的合成及其抗血小板聚集活性研究 总被引:1,自引:0,他引:1
4-色满酮类化合物和色酮类化合物具有广泛的生物活性。笔者曾发现4-色满酮3位Mannich碱类化合物具有显著的抗血小板聚集活性,为了考察在4-色满酮的3-位Mannich碱类化合物中3-位胺甲基侧链是否为加强活性的必需基团,为确定其药效构象提供信息,笔者设计合成了4种4-色满酮芳环Mannich碱类化合物,同时又合成了3种色酮芳环Mannich碱类化合物。所合成的目标化合物均未见文献报道,其组成和结构经红外光谱、质谱和核磁共振氢谱确认。采用Born's比浊法对目标化合物进行了抗血小板聚集活性的体外筛选。实验结果表明,目标化合物对ADP和胶原诱导的家兔血小板聚集均具有显著的体外抑制活性。 相似文献
9.
10.
11.
12.
山胡椒抑制体内外α-糖苷酶活性研究 总被引:2,自引:0,他引:2
对山胡椒抑制酵母α-葡萄糖苷酶和大鼠小肠α-葡萄糖苷酶活性进行了研究。利用96微孔板法检测其α-葡萄糖苷酶抑制活性。结果表明,抑制酵母α-葡萄糖苷酶实验中,山胡椒石油醚部位(IC50=229.70μg/mL)、乙酸乙酯部位(IC50=259.10μg/mL)和正丁醇部位(IC50=165.80μg/mL)活性低于阳性对照Acarbose(IC50=1081.27μg/mL);抑制大鼠小肠α-葡萄糖苷酶实验中,仅有乙酸乙酯部位(IC50=418.17μg/mL)具有活性,阳性对照Acarbose未检测出其IC50。实验证明,山胡椒各提取部位具有较好抑制酵母α-葡萄糖苷酶活性,但只有乙酸乙酯部位具有良好的大鼠小肠α-葡萄糖苷酶抑制活性。 相似文献
13.
藓类提取物对白菜软腐病菌的抑菌活性 总被引:1,自引:0,他引:1
以欧文氏菌(Erwinia carotovora)为供试菌,对24种藓类乙醇提取物进行抑菌活性筛选。结果表明,有15种藓类提取物对欧文氏菌表现出不同程度抑菌作用,并将有较强抑菌作用的提取物对欧文氏菌进行了最低抑菌浓度MIC测定。 相似文献
14.
紫外分光光度法测定中药中黄嘌呤氧化酶抑制活性研究 总被引:2,自引:0,他引:2
黄嘌呤氧化酶(XOD)抑制剂是一类重要的抗痛风药物。寻求具有强XOD抑制活性的天然药物及其活性成分具有重要意义。采用紫外分光光度法对一系列中药中XOD抑制活性进行了直接测定。考察了抑制活性最强药物各部分的活性,并对其主要活性部位分离出了一个活性成分,最后采用IR、MS1、H NMR和13C NMR分析手段对其进行了鉴定。结果表明,丹皮具有最强XOD抑制活性,乙酸乙酯部分为其主要活性部位,没食子酸为其活性成分之一。 相似文献
15.
16.
17.
A cytosolic protein, that is inhibitory to neutral cholesteryl ester hydrolase, has been investigated in the livers of female
rats using microsomes isolated from the mammary gland of lactating rats as an enzyme source. To facilitate comparisons, inhibitory
activity is expressed in terms of the amount (μg) of cytosolic protein required to reduce esterase activity by 50% and is
compared to the hepatic content of both cholesterol and cholesteryl esters. The experiments revealed a sexual difference in
the level of inhibitory activity, with the livers of both suckling and mature male animals containing less of the material
than the corresponding females. Alterations in the physiological status of the females, such as pregnancy and lactation, led
to a decrease in the activity of the protein. This was reversed by blocking lactation with a combination of an antiserum to
rat growth hormone and the anti-prolactin drug, bromcoriptine, but not by premature weaning of the animals. Food withdrawal
for 24 hr also had the effect of increasing inhibitory activity. In general the cholesteryl ester content of the livers correlated
with the level of inhibitory activity. Thus the activity of the cytosolic inhibitor of neutral cholesteryl ester hydrolase
responded to changes in both the hormonal and the nutritional status of the female animal. It is suggested that the presence
of the greater cholesteryl ester hydrolase inhibitory activity in the female liver may help to explain the lower risk of coronary
heart disease in premenopausal females by facilitating increased hepatic storage of the sterol in the form of the ester. 相似文献
18.
High values of residual trypsin inhibitory activity found for heat-treated beans indicated the occurrence of artifices due to the methodology. A critical evaluation of the methods in use and of possible interferents was performed trying to determine the most adequate way of measuring residual trypsin inhibitory activity. Results showed that extraction conditions, pH of reaction and sample preparation are responsible for significant alterations of the values found, requiring careful standardization. This is the first report about the influence of lyophilization upon residual trypsin inhibitory activity of cooked beans. 相似文献
19.
通过对DPPH自由基的清除能力对鱼眼草的抗氧化活性进行评价;考察了鱼眼草的抗氧化、α-葡萄糖苷酶抑制活性和抑菌活性。应用体外α-葡萄糖苷酶筛选模型进行鱼眼草酶抑制活力的测定;采用KB纸片法和肉汤稀释法测定鱼眼草的抑菌活性。结果:鱼眼草的化学成分及各部位提取物的抗氧化活性并不理想;化合物脱镁叶绿素甲酯(IC50=19.23 mg.L-1)和柳穿鱼素-7-葡萄糖甙(IC50=30.27 mg.L-1)的体外抑制α-糖苷酶抑制活性远高于对照acarbose(IC50=1081.27 mg.L-1);KB纸片法表明部分化合物和提取物具有较好的抑菌活性,肉汤稀释法表明乙酸乙酯部位的抑菌活性较好(金黄色葡萄球菌、肺炎克雷伯氏菌、铜绿假单胞菌的MIC分别为32、64、128μg.mL-1)。 相似文献
20.
2,4,6,4'-四羟基脱氧安息香的合成及其抑制酪氨酸酶活性的研究 总被引:3,自引:0,他引:3
合成2,4,6,4'-四羟基脱氧安息香(THDB),对其抑制酪氨酸酶活性进行评价。在无水氯化锌和氯化氢存在下,以间苯三酚和对羟基苯乙腈为原料,进行THDB的合成,并对所得化合物在0.05%、0.10%、0.20%、0.25%、0.30%、0.35%、0.40%七个浓度下与根皮素、熊果苷和曲酸进行抑制酪氨酸酶对比实验。收率由原来报导的46.5%提高到60.0%,在0.4%浓度时THDB对酪氨酸酶的抑制率达98.2%。本工艺是合成THDB的较佳工艺,THDB对酪氨酸酶的抑制作用比熊果苷和曲酸好,与根皮素相当。 相似文献