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1.
Introduction of acyclic chain for synthesis of acyclonucleoside derivatives was achieved in a simple and convenient way. Silylated pyrimidine or purine bases were treated with 1,3-dioxolane, trimethyl chlorosilane and metal iodide, such as KI and NaI, all together at room temperature. By this method, 2-thiopyrimidine derivatives were also obtained in good yield, using 2 molecular equivalents of 1,3-dioxolane.  相似文献   

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A simple, mild, and environmentally benign synthesis procedure of pyranoid glycals is described. In a novel fashion, protected glycopyranosyl bromides undergo the reductive elimination in the presence of zinc in phosphate buffer at room temperature. The pyranoid glycals were obtained in good-to-excellent yields (18 examples).  相似文献   

3.
A straightforward and simple, but powerful and direct, method is presented for both the detection and quantitation of cobalamin impurities in either commercial cobalamins or in metastable cobalamins (Cbls), such as RSCbls. The method is, quite simply, the use of the aromatic region of the 1H NMR of cobalamins; it is a method developed as an outgrowth of our work preparing metastable thiolatocobalamins (RSCbls) and is a method that proved necessary for characterizing those (and by inference other) cobalamins unstable to HPLC separation conditions (i.e., and, therefore, where the normally powerful HPLC method so commonly used in cobalamin chemistry fails). Despite considerable, prior, modern multidimensional NMR literature on cobalamins, the present method has not yet been indicated explicitly, nor has anyone reported previously the NMR data required to prove that the method works (i.e., the data for a series of cobalamins and their common impurities proving that they have different chemical shifts in the aromatic region of their 1H NMR when examined under identical NMR solvent, pH and other conditions). The direct NMR method is easy to perform, readily quantitated and applicable to species unstable to the HPLC conditions required to separate cobalamin impurities. The results have allowed quantitation of the 5-11% impurities in, for example, commercial HOCb1.HX, results which document that some commercially available cobalamins are not as pure as the manufacturers' claims.  相似文献   

4.
A convenient automated method for measuring inorganic phosphate based on the malachite green reaction with a phosphomolybdate complex has been developed. Less than 100 pmol of inorganic phosphate can be readily quantitated by the method which utilizes standard AutoAnalyzer equipment. Inorganic phosphate is measured in sample volumes of less than 0.1 ml and without interference by a number of phosphorylated metabolic intermediates or nucleotides. This methodology is especially useful in the analysis of hydrolytic processes involving phosphorylated substrates.  相似文献   

5.
A simple convenient method for the synthesis of guanosine acyclic analogues with the nucleic base attached to the primary carbon atom is proposed. The method involves treatment of trimethylsilyl derivative of guanine with agents of general formula ROCH2Cl in the absence of Lewis acids. 9-Substituted derivatives of guanine were prepared by this method with 50-65% yields.  相似文献   

6.
介绍了植物挥发物提取的一种简易方法——液氮冷凝法。利用液氮的制冷原理对植物挥发性物质进行提取收集,当携带植物挥发性物质的纯净空气带动供试植物组织的挥发性物质通过一置有U形玻璃管的液氮罐时,由于液氮的低温作用,挥发性物质在U形管内壁上遇冷凝结。该提取装置简单,由硅胶柱、活性碳柱、流量计、锥形瓶、U形管、液罐及各种连接管构成,容易组装。利用该装置提取的挥发性物质可以用于生测,去除水分后还可用于电生理以及挥发性物质化学组成分析等。  相似文献   

7.
One of two chromophores is formed on heating the mantle tissue of Mytilus edulis with thiobarbituric acid (TBA). Application of the test to male mussels yields a strong yellow colour (λmax453 and 490 nm), whereas in females, a pink colour (λmax532 nm) develops. While the latter is characteristic of the products of lipid peroxidation, it appears that the yellow colour may be derived from the 2-deoxyribose moiety of DNA. The TBA reaction can be used for the rapid, accurate sex identification in Mytilus edulis over 9–10 months of the year.  相似文献   

8.
A convenient method for the ATPase assay.   总被引:28,自引:0,他引:28  
A new method for the determination of inorganic phosphorus released in ATPase assay has been evaluated. The method is based on the reduction of a phosphomolybdate complex by Elon in a copper acetate buffer. In contrast to current methods, there is no interference by ATP with color development. There is also less or no interference by other compounds usually present in ATPase assay media. The method is simple, sensitive, and reproducible.  相似文献   

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目的为了简化现有的华伯氏呼吸仪检测红细胞无氧糖酵解的方法,进行此项研究.方法实验用葡萄糖试剂盒,高氯酸,可见光分光光度计,氮气瓶和摇床.实验分4步进行任氏液.Trls-HCI溶液等试液的配制,任氏血的制备,红细胞无氧糖酵解率的测定和红细胞无氧糖酵解率的计算.结果用SOD保养液.在4℃条件下保存入红细胞75d时糖酵解率为86.2%±5.0%,明显优于GMA保养液39.2%±8.9%.结论不用华伯氏仪的红细胞无氧糖酵解率的测定方法,操作简便,方法准确可靠,在普通实验室即可进行.  相似文献   

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Radioactivity-labelled heme has usually been isolated from liver to which unlabelled carrier has been added by long, laborious techniques involving organis solvent extraction followed by crystallization. We have devised a simpler, rapid method for obtaining radiochemically-pure heme synthesized in vivo in rat liver from δ-amino[4-14C]levulinate, by modifying our previous procedure (Bonkowsky et al. (1975) J. Clin. Invest. 56, 1139–1148). This method, in which the heme is extracted into ethyl acetate/glacial acetic acid and in which porphyrins are removed from the heme-containing organic phase with HCl washes, does not require addition of carrier heme. The new method gives better heme recoveries than and heme specific activities identical to, those obtained using the crystallization method. In this new method heme must by synthesized from δ-amino[4-14C]levulinate; it not satisfactory to use [2-14C]-glycine substrate because non-heme counts are isolated in the heme fraction.  相似文献   

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韭菜迟眼蕈蚊简便人工饲养技术   总被引:8,自引:0,他引:8  
研究了以鲜净韭菜假茎为饲料,温度为20~25℃,相对湿度为50~70%条件下,可正常累代饲养韭菜迟眼簟蚊幼虫及繁殖后代的方法。用该方法经14代累代饲养的韭菜迟眼簟蚊,各代幼虫成活率、幼虫历期、平均蛹重、羽化率、单雌产卵量及孵化率均无明显差异,证明了方法的可靠性。  相似文献   

18.
M C Holley 《Tissue & cell》1992,24(5):613-624
Monoclonal antibodies have been produced to mammalian hair cell antigens using a simple in vitro kit. Antigen was crudely prepared from dissected cochlear tissue by detergent extraction. There was no need to purify hair cells. Hybridoma supernatents were screened most efficiently on dissociated cells fixed with acetone. The immunisation method is sensitive to nanograms of antigen and can generate responses to conserved or weak antigens. The kit requires very little previous experience with cell culture and generates monoclonal antibodies within 3-4 weeks. It has overcome a number of problems with production of antibodies to hair cells and it should prove to be a very valuable tool in many laboratories.  相似文献   

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Upon gel electrophoresis under standard conditions, RNA from the Russian strain of barley stripe mosaic virus (BSMV) yielded two components. The gels were stained with ethidium bromide, and the RNA-containing zones were excised and extracted. The RNA isolated was precipitated from the dilute (8–10 μg/ml) extract by addition of 0.2 CaCl2. The RNA preparation was, thereby, completely freed from polyacrylates present in the extract. The extracted components of the virus RNA had the same electrophoretic mobilities as those of the starting RNA preparation. They also retained their biological and messenger activity.  相似文献   

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