辅酶Q10超声波破碎法提取工艺条件研究

为了获得超声波提取辅酶Q10的最佳工艺条件,系统研究了利用超声波法提取时输出功率、每次辐射时间、工作总时间、水添加量等因素对细胞破碎和辅酶Q10提取效果的影响。结果表明,超声波提取辅酶Q10的最佳工艺条件为:输出功率500 W,每次辐射/间歇时间12 s/10 s,工作总时间12 min,水添加量45 mL/g;采用优化的超声波提取工艺,辅酶Q10提取量可达到1.196 mg/g。证明超声波破碎法提取辅酶Q10是可行的,与未破壁提取、研磨法及反复冻融法提取效果相比,辅酶Q10提取效果良好。     

Flavin mononucleotide control of glycolic Acid oxidase and photorespiration in corn leaves

Enzyme preparations from young corn shoots lacked the coenzyme, flavin mononucleotide, that is required for glycolic acid oxidation. When the coenzyme was added to the shoots, the rate of carbon dioxide production during photosynthesis increased. Shoots of wheat or oats did not lack the coenzyme.     

辅酶Q10应用的研究进展

辅酶Q10是一种脂溶性醌类化合物,在人体呼吸链中参与电子传递,具有促进细胞新陈代谢的功能。基于辅酶Q10的特点和作用,为进一步开发辅酶Q10,并对其进行有效的利用,以发挥其重要的价值,综述了辅酶Q10在医药卫生和美容护肤等领域中的应用及研究状况,并分析了辅酶Q10与其它药物之间的互作关系,并对其开发前景进行了展望。     

碱蓬中辅酶Q10的提取分离

[目的]为碱蓬中辅酶Q10的提取分离和工业化生产提供科学依据。[方法]用10%KOH-甲醇的醇碱皂化法从碱蓬中提取辅酶Q10,并用硅胶柱层析,经无水乙醇重结晶后,得黄色结晶。用熔点测定法和薄层层析法对黄色结晶进行定性鉴定,用HPLC法和Craven氏颜色试验法对其进行定量测定。[结果]无水乙醇重结晶后得到的晶体,其熔点为48.6~50.3℃,在碱性条件下,加入氰基乙酸乙脂后,生成了蓝色化合物,证明该结晶是辅酶Q10。用Craven氏颜色试验法测得碱蓬干粉中辅酶Q10的含量约为63.3μg/g,精制辅酶Q10结晶的纯度为93.2%。用HPLC法测得的辅酶Q10含量约为63.1μg/g。两种定量分析方法存在良好的线性关系。[结论]碱蓬是获取辅酶Q10的良好材料,有很好的开发前景。     

辅酶Q10产生菌的筛选及产物的定量检测

为了从实验室保存的酵母菌株中筛选产生辅酶Q10的菌株,采用麦芽汁培养酵母菌,皂化法萃取菌体中的辅酶Q10,可见光比色法和高压液相色谱法测定酵母菌中的辅酶Q10的含量。结果表明:筛选出2株较高产量的辅酶Q10产生菌,热带假丝酵母(C.tropicalis(cast).Berkhout)B021产量为7.420 mg/L、粟酒酵母(Schizosaccheromyces pombe Lindner)B147产量为7.488 mg/L。     

Leucine 2,3-aminomutase: a cobalamin-dependent enzyme present in bean seedlings

Leucine 2,3-aminomutase has been demonstrated in extracts of bean seedlings. The activity of this enzyme is stimulated by coenzyme B(12) and is inhibited by intrinsic factor. The inhibition is removed by the addition of coenzyme B(12). This evidence is consistent with the presence of a cobalamin-dependent enzyme in higher Plants.     

柠檬醛对黄曲霉细胞内两个氧化还原酶的影响

柠檬醛（citral）是单萜类小分子芳香醛，研究发现它能有效地抑制黄曲霉细胞内苹果酸脱氢酶和琥珀酸脱氢酶2种酶的活力，其中苹果酸脱氢酶的活力降低了29．2％（以NADP^ 为辅酸）和23．8％（以NAD^ 为辅酶），琥珀酸脱氢酶的活力降低了27．1％。     

丙酮研磨法提取麦麸中辅酶Q_(10)的工艺研究

采用丙酮研磨、石油醚萃取工艺提取麸皮中的辅酶Q10,研究不同提取条件对辅酶Q10提取量的影响,并采用正交试验对萃取料液比、温度、时间进行优化,确定了辅酶Q10的最佳提取条件,旨在为辅酶Q10的工业化生产提供理论依据。结果表明,丙酮研磨的最佳料液比为1∶4,石油醚萃取的最佳条件为料液比1∶6、温度85℃、时间75min,在此条件下辅酶Q10的提取量达到最大,为40.771μg/g。     

金属阳离子夹心三核金咪唑基化合物的电子结构和光物理性质

采用混合密度泛函方法,对一系列包含金属离子(Cr2+、W2+、Fe2+、Ru2+、Cd2+、Cu+、Ag+、Au+、In+、Tl+、Li+、Na+)的咪唑基三核金夹心化合物基态分子结构进行了优化;并采用含时密度泛函方法对这些夹心化合物的垂直激发态进行研究,描述了与发光过程相关的前线分子轨道特征.计算结果表明:夹心金属离...     

Lactic dehydrogenases: subfractionation of isozymes

Electrophoresis in polyacrylamide gel of homogenates of various organs from the mouse yields five major lactic dehydrogenase bands. If the gels are treated with beta-mercaptoethanol, subsequent electrophoresis produces 15 bands which show lactic dehydrogenase activity. This could be explained if one molecule of nicotinamide adenine dinucleotide (coenzyme) is attached to each of the monomeric subunits of lactic dehydrogenase and if mercaptoethanol can remove the coenzyme only from the muscle type. This is consistent with the hypothesis that intact lactic dehydrogenase is a tetramer.     

猪心中提取和纯化辅酶Q10（联产CytC）

辅酶Ｑ１０和细胞以素Ｃ是促生物氧化酶类生化药物,本试验从猪心中提了和纯化辅酶Ｑ１０,并联产细胞以素Ｃ。猪心以酸性水液粗提,细胞色素Ｃ经人造沸石吸附,洗脱,盐析,三氯乙酸沉淀,弱酸性阳离子吸附,真空干燥得２２５ｍｇＣｙｔＣ／ｋｇ猪心,纯度７９％,提取后的猪心渣,用醇皂化法,经硅胶桂层板,无水乙醇结晶,重结晶,每千克猪心中撮辅酶Ｑ１０７５ｍｇ,含量为９５．３％。     

放射农杆菌产辅酶Q10培养基的优化研究

以放射农杆菌为出发菌株,采用6因素二次通用旋转组合设计法对影响放射农杆菌发酵产辅酶Q10的相关因素进行了研究。结果选取到6种有显著效应的因素：葡萄糖、蔗糖、蛋白胨、酵母膏、异戊醇和L-甲硫氨酸。运用高压液相色谱法对辅酶Q10的含量进行测定,经DPS模拟寻优,建立二次回归方程,优化了培养基的组成。结果表明,当葡萄糖2g/L、蔗糖1g/L、蛋白胨1．25g/L、酵母膏0．75g/L、异戊醇0．075g/L、L．甲硫氨酸0．0375g/L或葡萄糖1．5g/L、蔗糖1．5g/L、蛋白胨1．5g/L、酵母膏1g／L、异戊醇0．05g/L、L．甲硫氨酸0．025g/L时,辅酶Q10的产量最大。     

Action spectra for phase shifts of a circadian rhythm in Drosophila

Action spectra were determined for lightinduced phase shifts of the circadian rhythm of adult emergence in Drosophila pseudoobscura. The action spectra for advance and delay phase shifts are similar; the most effective wavelengths are in the blue region, with a sharp cutoff above 500 nanometers. This similarity suggests that the same photoreceptive pigment mediates both advance and delay phase shifts.     

辅酶Q10高产菌株的选育

以根癌土壤杆菌(Agrobacterium tumefaciens)1．1416为出发菌株，考察了紫外线(UV)、1-甲基-3-硝基-1-亚硝基胍(NTG)和硫酸二乙脂(DES)对该菌株产生辅酶Q10能力的诱变效应，并结合辅酶Q10合成途径设计了快速筛选辅酶Q10高产菌株的模型。结果表明：NTG和DES交替诱变处理根癌土壤杆菌1．1416具有较好的诱变效果，筛选到的突变株AGR0619和AGR0610的辅酶Q10总产量分别提高了137．49％和156．07％。     

Global warming, elevational range shifts, and lowland biotic attrition in the wet tropics

Many studies suggest that global warming is driving species ranges poleward and toward higher elevations at temperate latitudes, but evidence for range shifts is scarce for the tropics, where the shallow latitudinal temperature gradient makes upslope shifts more likely than poleward shifts. Based on new data for plants and insects on an elevational transect in Costa Rica, we assess the potential for lowland biotic attrition, range-shift gaps, and mountaintop extinctions under projected warming. We conclude that tropical lowland biotas may face a level of net lowland biotic attrition without parallel at higher latitudes (where range shifts may be compensated for by species from lower latitudes) and that a high proportion of tropical species soon faces gaps between current and projected elevational ranges.     

Biased signaling pathways in β2-adrenergic receptor characterized by 19F-NMR

Extracellular ligand binding to G protein-coupled receptors (GPCRs) modulates G protein and β-arrestin signaling by changing the conformational states of the cytoplasmic region of the receptor. Using site-specific (19)F-NMR (fluorine-19 nuclear magnetic resonance) labels in the β(2)-adrenergic receptor (β(2)AR) in complexes with various ligands, we observed that the cytoplasmic ends of helices VI and VII adopt two major conformational states. Changes in the NMR signals reveal that agonist binding primarily shifts the equilibrium toward the G protein-specific active state of helix VI. In contrast, β-arrestin-biased ligands predominantly impact the conformational states of helix VII. The selective effects of different ligands on the conformational equilibria involving helices VI and VII provide insights into the long-range structural plasticity of β(2)AR in partial and biased agonist signaling.     

植物4-香豆酸:辅酶A连接酶(4CL)研究进展

综述了4-香豆酸:辅酶A连接酶(4CL)的功能、功能与结构的关系及晶体学方面的研究进展,以期为4CL蛋白质的结构和功能的进一步研究提供依据。     

秦川牛心肌渣辅酶Q10的萃取方法研究

为综合利用资源,以提取细胞色素C后的秦川牛心肌渣为原料,采用醇碱皂化,石油醚萃取,硅胶柱层析,无水乙醇重结晶得到CoQ10。研究结果表明,醇碱皂化适宜温度为90℃,皂化时间为30min,萃取2次。经薄层层析样品仅有一个斑点,Rf=0.56（a=7.5 cm,c=13.5 cm）,样品与标准CoQ10的紫外吸收光谱相同,在275nm处有最大吸收峰,定量测定样品的纯度为91.2%。从牛心肌渣萃取CoQ10的方法是可行的。     

Glacial-interglacial changes in moisture sources for greenland: influences on the ice core record of climate

Large, abrupt shifts in the (l8)O/(16)O ratio found in Greenland ice must reflect real features of the climate system variability. These isotopic shifts can be viewed as a result of air temperature fluctuations, but determination of the cause of the changes-the most crucial issue for future climate concerns-requires a detailed understanding of the controls on isotopes in precipitation. Results from general circulation model experiments suggest that the sources of Greenland precipitation varied with different climate states, allowing dynamic atmospheric mechanisms for influencing the ice core isotope shifts.