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1.
Acetaldehyde, the end product of oxidative ethanol metabolism, contributes to alcohol-induced disease in the liver, but cannot account for damage in organs such as the pancreas, heart, or brain, where oxidative metabolism is minimal or absent; nor can it account for the varied patterns of organ damage found in chronic alcoholics. Thus other biochemical mediators may be important in the pathogenesis of alcohol-induced organ damage. Many human organs were found to metabolize ethanol through a recently described nonoxidative pathway to form fatty acid ethyl esters. Organs lacking oxidative alcohol metabolism yet frequently damaged by ethanol abuse have high fatty acid ethyl ester synthetic activities and show substantial transient accumulations of fatty acid ethyl esters. Thus nonoxidative ethanol metabolism in addition to the oxidative pathway may be important in the pathophysiology of ethanol-induced disease in humans.  相似文献   

2.
 分析了甲醇和乙醇作为柴油替代燃料的可行性及应用前景,对甲醇或乙醇、柴油及水的混烧比例提出了建议。同时根据云南农业大学在X195型柴油机上增设的甲/乙醇供给系统提出了改进举措及试验目标。  相似文献   

3.
采用重量法测量了280.55~318.75K印楝素A在甲醇、无水乙醇、丙酮和乙酸乙酯中的溶解度。结果表明印楝素A在不同有机溶剂中的溶解度均随温度升高而增加,在乙酸乙酯和丙酮中的溶解度较大但随温度升高增加相对不明显;在甲醇和无水乙醇中的溶解度较小但随温度升高显著增加,溶解度最大的乙酸乙酯最适合作为印楝素A的提取溶剂。采用多项式经验方程和理想溶液方程对试验数据进行关联,结果表明,这2种方程均能较好地关联溶解度试验数据。根据关联方程计算表明冷却结晶理论收率较高的无水乙醇和甲醇适合作为冷却结晶纯化印楝素A的溶剂。  相似文献   

4.
棉花(新陆早36)生殖生长期喷施外源甲醇水溶液后,检测分析了叶片中乙醇酸氧化酶活性、光合速率及籽棉产量。结果表明,不同生长期,甲醇水溶液处理后对乙醇酸氧化酶活性的抑制作用强弱表现为:盛蕾期>盛花期>铃期;对乙醇酸氧化酶活性的抑制作用为:30%甲醇水溶液>20%甲醇水溶液>10%甲醇水溶液。当处理组叶片乙醇酸氧化酶活性受到不同程度抑制时,光合速率相应提高,籽棉产量亦增高。试验结果表明,高光强、高温情况下喷施外源甲醇水溶液增强光合作用效率,与其参与棉花作物的光呼吸代谢有关。  相似文献   

5.
以甲醇、乙醇、异丙醇、甲醛和戊二醛为效应物,研究它们对中华绒螯蟹N-乙酰-β-D-氨基葡萄糖苷酶(NAGase)活力的影响.结果表明:戊二醛对NAGase活力影响不大;低浓度的甲醇和乙醇对NAGase有激活作用;高浓度的甲醇、乙醇、异丙醇和甲醛对NAGase的作用为可逆抑制.甲醇、乙醇、异丙醇对NAGase表现出竞争性抑制,抑制常数(KI)分别为3.663、0.360和0.480 mol.L-1;甲醛表现为非竞争性抑制类型,其KI为0.288 mol.L-1.  相似文献   

6.
酱油中大豆异黄酮含量测定及其提取工艺研究   总被引:1,自引:0,他引:1  
采用无盐发酵制备酱油,反相高效液相色谱(RHPLC)法测定异黄酮含量,并对酱油中大豆异黄酮的提取分离方法进行了研究。结果表明:采用乙醇沉淀除杂可以较好地提取分离酱油中的大豆异黄酮;由于发酵过程中原料的消耗和微生物的代谢活动,酱油中大豆异黄酮含量较原料豆粕的异黄酮含量大幅度提高。  相似文献   

7.
Prolonged consumption of ethanol enhances the activities of the hepatic microsomal ethanol oxidizing system and of reduced nicotinamide-adenine dinucleotide phosphate oxidase, but not of catalase. The oxidase-catalase system is not part of the microsomal ethanol oxidizing system since catalase inhibitors dissociate ethanol oxidation by the two pathways. Enhanced reduced nicotinamide-adenine dinucleotide phosphate oxidase activity may contribute to liver injury, possibly by favoring lipoperoxidation.  相似文献   

8.
Armillaria mellea produced abundant rhizomorphs when grown on a chemically defined medium containing ethanol at concentrations as low as 50 parts per million. In the absence of ethanol no rhizomorphs were formed. Rhizomorph production was also stimulated by I-propanol, isopropanol, and 1-butanol as well as by acetaldehyde (to a lesser extent). Potassium acetate had very slight stimulating effect, and methanol was completely ineffective.  相似文献   

9.
鱼藤酮在不同溶剂中的紫外吸收研究   总被引:5,自引:0,他引:5  
测定了鱼藤酮在甲醇、三氯甲烷、乙醇、四氯化碳等溶剂中的吸收情况。结果表明,鱼藤酮在不同的溶剂中,其紫外吸收峰和吸收图谱是不完全相同的,它在上述4种溶剂中的最大吸收波长分别是218.0、294.0、211.0和290.0nm。此外,确定了鱼藤酮的紫外检测波长为293.0nm。  相似文献   

10.
为探究棉株中缩合单宁的最佳测试提取条件,选取甲醇和乙醇的水溶液作为提取剂,采用香草醛-盐酸比色法测定棉株中缩合单宁的含量。先通过单因素试验确定了甲醇和乙醇各自的最佳提取条件,然后比较这两种提取剂的提取效果,确定乙醇为较好的提取剂,最后通过正交试验确定了乙醇的最优提取条件为:料液比1∶20(g/mL),乙醇浓度40%(V/V),超声时间30 min。  相似文献   

11.
桑椹醋提取物对二苯代苦味酰基自由基(DPPH·)的清除作用   总被引:18,自引:4,他引:18  
用DPPH法测定了桑椹醋的甲醇、乙醇、丙酮、乙酸乙酯提取物的抗氧化活性,并与叔丁基对苯二酚(TBHQ)进行比较。结果表明,4种提取物对DPPH·自由基均有较强的清除作用,清除能力均高于TBHQ,其大小顺序依次为甲醇提取物>乙醇提取物>丙酮提取物>乙酸乙酯提取物》TBHQ。  相似文献   

12.
Brain alcohol dehydrogenase   总被引:1,自引:0,他引:1  
Significant alcohol dehydrogenase activity has been demonstrated in the soluble fraction of rat brain and is very similar to the liver enzyme in kinetic properties and responses to inhibitors. A cerebral mechanism that oxidizes ethanol may play a significant role in local adjustments during exposure to ethanol and in the pathogenesis of the neural disorders associated with chronic alcohol ingestion or withdrawal.  相似文献   

13.
Chalaropsis thielavioides, a filamnentous fungus. produces a characteristic ester-like aroma on potato dextrose broth. By gas-liquid chromatographic techniques, the major aroma-producing substances have been identified as isobutyl and ethyl acetate. Lesser amounts of isoamyl acetate, ethanol, and methanol were also present.  相似文献   

14.
Glycerol metabolism in the human liver: inhibition by ethanol   总被引:3,自引:0,他引:3  
Glycerol is metabolized predominantly in the liver, the first step presumably being phosphorylation to alpha-glycerophosphate. When ethanol is present in the blood the rate of glycerol uptake by the splanchnic organs is reduced to about one-third of the control value. At the same time glycerophosphate accumulates in the liver. Hepatic blood flow and oxygen consumption are not influenced by the combined infusion of glycerol and ethanol. The phenomenon may be connected with the increased concentration of the reduced form of diphosphopyridine nucleotide present in the liver during ethanol metabolism.  相似文献   

15.
采用超临界CO2萃取技术提取葡萄籽中低聚原花青素(OPC’s),并初步分析了产物的构成。结果表明:不使用夹带剂时,不能萃取出OPC’s;甲醇或乙醇作为夹带剂时可以增加OPC’s的提取率,且甲醇效果更好,但总体提取率仍较低。进一步的色谱分析表明,产物中含有儿茶素、表儿茶素及两种二聚体。  相似文献   

16.
以甲醇、乙醇、苯—乙醇为夹带剂,考察超临界CO2流体处理对福建产马尾松、檫木渗透性及失重率的影响。结果表明,试材经超临界CO2流体处理后,渗透性得到了较大地改善,夹带剂的使用更有利于木材渗透性的提高,在3种夹带剂中,以苯—乙醇效果最佳,马尾松、檫木的渗透性变化率最高分别可达504%和339%。  相似文献   

17.
研究了不同萃取溶剂对红景天多酚萃取率的影响,并用DPPH(1,1-二苯基-2-三硝基苯肼)和O2.-(超氧阴离子)法研究了多酚的抗氧化活性。结果表明:水溶液中加入一定比例的甲醇、乙醇等有机溶剂可明显提高红景天多酚的萃取率,其中以50%乙醇的萃取率最高。红景天多酚对DPPH和O2.-的清除效果明显,最高可达90%。相关性分析表明,多酚的浓度与其抗氧化活性有一定的相关性。  相似文献   

18.
采用甲醇法、乙醇法、超声波水法、碱法等4种方法对哈茨木霉菌(Trichoderma harzianum)T2菌株分生孢子中的抗菌物质进行了提取,并测定了各种粗提物对齐整小核菌(Sclerotium rolfsii)的抑菌活性及温度对粗提物抑菌活性的影响.结果表明,用不同方法提取的哈茨木霉T2菌株粗提物对齐整小核菌有不同程度的抑制效果,其中以超声波水法提取物对齐整小核菌的抑制效果较好,温度对粗提物的抑菌活性有明显的影响.  相似文献   

19.
陈丛瑾  潘柳姣  韦龙宾 《安徽农业科学》2007,35(36):11879-11880
采用甲醇、乙醇、丙酮、乙酸乙酯4种有机溶剂冷浸提取,分别得到了甲醇提取物(ME)、乙醇提取物(EE)、丙酮提取物(AE)和乙酸乙酯提取物(EAE)。然后采用二苯代苦味酰肼自由基(DPPH)法对不同质量浓度的各提取物进行了自由基清除实验。结果表明,4种溶剂提取得到的姜黄提取物对DPPH自由基均有一定的清除作用,不同溶剂所得提取物对自由基的清除作用有差别,其中以丙酮提取物的效果最佳。鲜姜黄可作为抗氧化物质资源加以开发利用。  相似文献   

20.
马铃薯茎叶中茄尼醇提取方法优化与比较   总被引:1,自引:0,他引:1  
为了探究马铃薯茎叶中茄尼醇适宜的提取溶剂和提取方法,选取从宁夏固原采收的同一批马铃薯茎叶为研究对象,分别以95%乙醇、甲醇为提取溶剂,并设置不同的提取次数和提取时间,优化了加热回流提取马铃薯茎叶中茄尼醇的方法,并比较了加热回流提取、冷浸提取和超声提取马铃薯茎叶中茄尼醇的效果。结果表明,采用95%乙醇加热回流提取马铃薯茎叶中茄尼醇,提取2次,每次提取1.5 h,茄尼醇提取率达到96.85%,明显高于甲醇作为提取溶剂(47.04%);其浸膏得率为7.63%,与甲醇作为提取溶剂(8.07%)相当,可降低后期茄尼醇的精制和纯化的成本。该方法简便、可行,试剂还可反复回收利用,可行性强。  相似文献   

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