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141.
A high-performance liquid chromatographic method with ultraviolet detection has been developed for the determination of bretylium in plasma. Following a single-step solid-phase extraction procedure, bretylium is selectively isolated and well recovered from plasma. The assay sensitivity is 0.156 micrograms/ml from 250-microliters plasma samples and its linearity was assessed up to 40 micrograms/ml. The method is accurate (101.0 +/- 5.4%) and precise (maximum coefficient of variation of 8%). It provides a simple and time-saving alternative to existing methods and is particularly suitable for pharmacokinetic studies. 相似文献
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Silva Daniel Pereira Pessoa Adalberto Roberto Inês-Conceição Vitolo Michele 《Applied biochemistry and biotechnology》2001,91(1-9):605-613
A batch culture of Saccharomyces cerevisiae for the production of hexokinase was carried out in a 5-L fermentor containing 3 L of culture medium, which was in oculated
with cell suspension (about 0.7 g/L), and left ferm entingat 35°C and pH 4.0. The aeration and agitation were adjusted to
attain k
La values of 15, 60, 135, and 230 h−1. The highest hexokinase productivity (754.6 U/[L h]) and substrate-cell conversion yield (0.21 g/g) occurred for a k
La of 60 h−1. Moreover, the formation of hexokinase and cell growth are coupled events, which is in accordance with the constitutive character
of this enzyme. Hexokinase formation for k
La>60 h−1 was not enhanced probably owing to saturation of the respiratory pathway by oxygen. 相似文献
146.
147.
M. Sc. Patrik Tholen M. Sc. Zhaowen Dong Dr. Marc Schmidtmann Dr. Lena Albers Prof. Dr. Thomas Müller 《Angewandte Chemie (International ed. in English)》2018,57(40):13319-13324
The synthesis of two η5‐aminoborole complexes of germanium(II) from the reaction of a germole dianion with aminoboron dichlorides is reported. This reaction constitutes a remarkable example of a germole‐to‐borole transformation. The two aminoborole complexes of germanium(II) were fully characterized by multinuclear NMR spectroscopy, IR spectroscopy, HRMS, and, in one case, by X‐ray crystallography. The results of quantum‐mechanical calculations favor the electronic structure of a half‐sandwich complex of GeII over an ionic representation with a germanium dication stabilized by an aromatic aminoborole dianion. 相似文献
148.
Sami E. Varjosaari Vladislav Skrypai Sharon M. Herlugson Thomas M. Gilbert Marc J. Adler 《Tetrahedron letters》2018,59(29):2839-2843
1-Hydrosilatrane, a safe and easy-to-handle reducing reagent that can be inexpensively accessed, has been shown to reduce prochiral ketones asymmetrically in the presence of chiral 1,2-aminoalcohols with ees ranging from 8% to 86%. The best result was achieved using ephedrine as the source of chirality, which is readily commercially available. The additive can be recovered through extraction and reused without any erosion of enantioselectivity. 相似文献
149.
Dr. Jens Atzrodt Dr. Volker Derdau Prof. Dr. William J. Kerr Dr. Marc Reid 《Angewandte Chemie (International ed. in English)》2018,57(12):3022-3047
The various applications of hydrogen isotopes (deuterium, D, and tritium, T) in the physical and life sciences demand a range of methods for their installation in an array of molecular architectures. In this Review, we describe recent advances in synthetic C?H functionalisation for hydrogen isotope exchange. 相似文献
150.
Paula Avelar Amado Vany Ferraz Denise Brentan da Silva Carlos Alexandre Carollo Ana Hortência Fonsêca Castro 《Natural product research》2018,32(5):610-615
The antioxidant and cytotoxic activities of petroleum ether and methanol extracts, fatty acids and methyl esters from leaves of Smilax brasiliensis were evaluated, and the composition of the extracts was determined. Palmitic, linoleic and linolenic acids were major components of the extracts. For antioxidant activity, all samples exhibited IC50 values lower than BHT (2,6-di-tert-butyl-4-methylphenol). The extracts, fatty acids and methyl esters from S. brasiliensis presented no toxicity to larvae of the brine shrimp, Artemia salina. Among the purified substances, only methyl linolenate showed toxicity (LD50 = 21.47 μg/mL). This study showed, for the first time, the composition of petroleum ether and methanol extracts from S. brasiliensis leaves, as well as the antioxidant and cytotoxic activities of extracts, fatty acids and methyl esters. 相似文献