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961.
Chemical fingerprint analysis and quantitative determination of steroidal compounds from Dioscorea villosa,Dioscorea species and dietary supplements using UHPLC‐ELSD
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Bharathi Avula Yan‐Hong Wang Zulfiqar Ali Troy J. Smillie Ikhlas A. Khan 《Biomedical chromatography : BMC》2014,28(2):281-294
Ultra high‐performance liquid chromatography (UHPLC) with evaporative light scattering detection was used for the quantification of steroidal saponins and diosgenin from the rhizomes or tubers of various Dioscorea species and dietary supplements that were purported to contain Dioscorea. The analysis was performed on an Acquity UPLC? system with an UPLC? BEH Shield RP18 column using a gradient elution with water and acetonitrile. Owing to their low UV absorption, the steroidal saponins were observed by evaporative light scattering detection. The 12 compounds could be separated within 15 min using the developed UHPLC method with detection limits of 5–12 µg/mL with 2 μL injection volume. The analytical method was validated for linearity, repeatability, accuracy, limits of detection and limits of quantification. The relative standard deviations for intra‐ and inter‐day experiments were <3.1%, and the recovery efficiency was 97–101%. The total content of standard compounds was found to be in the ranges 0.01–14.5% and 0.9–28.6 mg daily intake for dry plant materials and solid commercial preparations, respectively. UHPLC–mass spectrometry with a quadrupole mass analyzer and ESI source was used only for confirmation of the identity of the various saponins. The developed method is simple, rapid and especially suitable for quality control analysis of commercial products. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Hongming He Qian‐Qian Zhu Chuanqi Zhang Ying Yan Jing Yuan Jing Chen Cheng‐Peng Li Miao Du 《化学:亚洲杂志》2019,14(7):917-917
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正Living cells are open systems that exist far away from a state of thermodynamical equilibrium.They utilize the high-grade chemical energy provided by food to produce ATP and release ADP and Pi together with heat dissipation.Living cells exist in a non-equilibrium steady state(NESS),they replicate themselves and respond to various environmental changes via 相似文献
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Micro‐/Nanostructured Multicomponent Molecular Materials: Design,Assembly, and Functionality
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Prof. Dr. Dongpeng Yan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(13):4880-4896
Molecule‐based micro‐/nanomaterials have attracted considerable attention because their properties can vary greatly from the corresponding macro‐sized bulk systems. Recently, the construction of multicomponent molecular solids based on crystal engineering principles has emerged as a promising alternative way to develop micro‐/nanomaterials. Unlike single‐component materials, the resulting multicomponent systems offer the advantages of tunable composition, and adjustable molecular arrangement, and intermolecular interactions within their solid states. The study of these materials also supplies insight into how the crystal structure, molecular components, and micro‐/nanoscale effects can influence the performance of molecular materials. In this review, we describe recent advances and current directions in the assembly and applications of crystalline multicomponent micro‐/nanostructures. Firstly, the design strategies for multicomponent systems based on molecular recognition and crystal engineering principles are introduced. Attention is then focused on the methods of fabrication of low‐dimensional multicomponent micro‐/nanostructures. Their new applications are also outlined. Finally, we briefly discuss perspectives for the further development of these molecular crystalline micro‐/nanomaterials. 相似文献
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Determination of triapine,a ribonucleotide reductase inhibitor,in human plasma by liquid chromatography tandem mass spectrometry
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Triapine is an inhibitor of ribonucleotide reductase (RNR). Studies have shown that triapine significantly decreases the activity of RNR and enhanced the radiation‐mediated cytotoxicity in cervical and colon cancer. In this work, we have developed and validated a selective and sensitive LC‐MS/MS method for the determination of triapine in human plasma. In this method, 2‐[(3‐fluoro‐2‐pyridinyl)methylene] hydrazinecarbothioamide (NSC 266749) was used as the internal standard (IS); plasma samples were prepared by deproteinization with acetonitrile; tripaine and the IS were separated on a Waters Xbridge Shield RP18 column (3.5 µm; 2.1 × 50 mm) using a mobile phase containing 25.0% methanol and 75.0% ammonium bicarbonate buffer (10.0 mm , pH 8.50; v/v); column eluate was monitored by positive turbo‐ionspray tandem mass spectrometry; and quantitation of triapine was carried out in multiple‐reaction‐monitoring mode. The method developed had a linear calibration range of 0.250–50.0 ng/mL with correlation coefficient of 0.999 for triapine in human plasma. The IS‐normalized recovery and the IS‐normalized matrix factor of triapine were 101–104% and 0.89–1.05, respectively. The accuracy expressed as percentage error and precision expressed as coefficient of variation were ≤±6 and ≤8%, respectively. The validated LC‐MS/MS method was applied to the measurement of triapine in patient samples from a phase I clinical trial. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献