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971.
Douglas M. Sartore Deyber A. Vargas Medina Marcio D. Bocelli Marcela Jordan-Sinisterra Álvaro J. Santos-Neto Fernando M. Lanças 《Journal of separation science》2023,46(15):2300215
Sample preparation frequently is considered the most critical stage of the analytical workflow. It affects the analytical throughput and costs; moreover, it is the primary source of error and possible sample contamination. To increase efficiency, productivity, and reliability, while minimizing costs and environmental impacts, miniaturization and automation of sample preparation are necessary. Nowadays, several types of liquid-phase and solid-phase microextractions are available, as well as different automatization strategies. Thus, this review summarizes recent developments in automated microextractions coupled with liquid chromatography, from 2016 to 2022. Therefore, outstanding technologies and their main outcomes, as well as miniaturization and automation of sample preparation, are critically analyzed. Focus is given to main microextraction automation strategies, such as flow techniques, robotic systems, and column-switching approaches, reviewing their applications to the determination of small organic molecules in biological, environmental, and food/beverage samples. 相似文献
972.
Nina Wei Dandan Song Chang Lu Yong Jiang Qin Liu Lunyuan Liu Liu Xu Linwei Chen Zhipeng Chen 《Journal of separation science》2023,46(17):2300235
Aconitum carmichaelii is widely used to treat chronic and intractable diseases due to its remarkable curative effect, but it is also a highly toxic herb with severe cardiac and neurotoxicity. It has been combined with honey for thousands of years to reduce toxicity and enhance efficacy, but there has been no study on the chemical constituent changes in the honey-processing so far. In this study, the chemical constituents of A. carmichaelii before and after honey-processing were characterized by ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry. The results showed that a total of 118 compounds were identified, of which six compounds disappeared and five compounds were newly produced after honey-processing, and the cleavage pathway of main components was elucidated. At the same time, 25 compounds were found to have significant effects on different products, among which four compounds with the biggest difference were selected for quantitative analysis by ultra-high-performance liquid chromatography-tandem mass spectrometry. This study not only explained the chemical differences between the different products, but also helped to control the quality of the honey-processed products more effectively, and laid a foundation for further elucidating the mechanism of chemical constituent change during the honey-processing of A. carmichaelii. 相似文献
973.
Da-Hee Park Hee-Jung Cho Se-Hyeong Kang Hong-Hee Lee Jae-Yong Shin A. M. Abd El-Aty Ho-Chul Shin 《Journal of separation science》2023,46(20):2300377
A sensitive and accurate analytical method was developed and validated to detect bambermycin, a commonly used antibiotic in animal feed and livestock. The presence of bambermycin residues in food products can pose health risks to consumers, emphasizing the need for a sensitive and accurate analytical method. A reversed-phase analytical column was utilized with a mobile phase comprising 0.005 mol/L ammonium acetate in 5% acetonitrile (A) and 0.005 mol/L ammonium acetate in 95% acetonitrile (B) to achieve effective chromatographic separation. Quantitative determination of bambermycin in various samples, including beef, pork, chicken, milk, eggs, flatfish, eel, and shrimp, was performed using ultra-high-performance liquid chromatography-tandem mass spectrometry. Sample extraction involved a mixture of methanol and a 25% ammonium hydroxide solution, followed by low-temperature purification and phospholipid removal utilizing a Phree cartridge. The method exhibited a satisfactory recovery rate ranging from 69% to 100%. Validation results demonstrated the reliability, robustness, and accuracy of the method, exhibiting good linearity, precision, and recovery. This validated method can be applied for routine analysis of bambermycin residues, assisting in the development of effective monitoring and control measures to ensure the safety of livestock and aquatic products. 相似文献
974.
Zeynep Kalaycıoğlu 《Journal of separation science》2023,46(22):2300391
Histamine is a biogenic amine found in various body tissues and responsible for many critical vital activities. It is also responsible for allergic reactions in the body. Ingestion of foods containing high amounts of histamine can cause fatal allergic reactions. Albumin in plasma controls drugs and free concentrations of bioactive constituents taken to the body with food. Hence, this study aimed to characterise the interactions of histamine with bovine serum albumin. Capillary electrophoresis in the frontal analysis mode was employed in this study as a practical approach for assessing histamine-bovine serum albumin affinity. The plateau-shaped free histamine peak was well separated from the bovine serum albumin (BSA)-histamine complex peak. The free histamine concentration was obtained by following the height of the free histamine peak. Whereas the bound histamine concentrations were obtained by calculating the difference between the height of total and free histamine peaks. Histamine bound to BSA at one independent site with a Kb value of 2.50 × 103 L/mol. Moreover, an in-silico molecular docking method was performed, and it was revealed that the binding site of histamine was located closer to Lysine-131 in subdomain IIA of bovine serum albumin. 相似文献
975.
Dr. Amit Kumar Chattopadhyay Vu Linh Ly Dr. Shashidhar Jakkepally Dr. Gilles Berger Prof. Dr. Stephen Hanessian 《Angewandte Chemie (International ed. in English)》2016,55(7):2577-2581
Herein we describe the first synthetic efforts toward the total synthesis of isodaphlongamine H, a calyciphylline B‐type alkaloid. The strategy employs a chemoenzymatic process for the preparation of a functionalized cyclopentanol with a quaternary center. This molecule is elaborated to form an enantiopure 1‐aza‐perhydrocyclopentalene core, representing rings A and E of all calyciphylline B‐type alkaloids. Further transformations involve the formation of a cyclic enaminone, 1,4‐conjugate addition with a cyclopentenyl subunit, and intramolecular aldol cyclization to achieve a pentacyclic intermediate, ultimately forming isodaphlongamine H in a total of 24 steps from the commercially available compound 2‐carbethoxycyclopentanone. Isodaphlongamine H exhibits promising inhibitory activity against a panel of human cancer cell lines. 相似文献
976.
977.
Bioisosteric Exchange of C
‐Chloro and Methyl Substituents: Synthesis and Initial Biological Studies of Atpenin A5 Analogues
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Simon Krautwald Dr. Christian Nilewski Dr. Mihoko Mori Prof. Dr. Kazuro Shiomi Prof. Dr. Satoshi Ōmura Prof. Dr. Erick M. Carreira 《Angewandte Chemie (International ed. in English)》2016,55(12):4049-4053
Asymmetric synthesis and initial biological studies of two analogues of a naturally occurring chlorinated antifungal agent, atpenin A5, are described. These analogues were selected on the basis of Cl→CH3 or H3C→Cl exchanges in the side‐chain of atpenin A5. The interchange of chloro and methyl substituents led to complex II inhibitors with equal IC50 values. This suggests that Cl?Me bioisosteric exchange can be realized in aliphatic settings. 相似文献
978.
Dr. Zhiqiang Ma Dr. Xiao Wang Dr. Yuyong Ma Prof. Dr. Chuo Chen 《Angewandte Chemie (International ed. in English)》2016,55(15):4763-4766
Axinellamines A and B are broad‐spectrum antibacterial pyrrole–imidazole alkaloids that have a complex polycyclic skeleton. A new asymmetric synthesis of these marine sponge metabolites is described herein, featuring an oxidative rearrangement and an anchimeric chlorination reaction. 相似文献
979.
Stefan Fischer Nikolas Huwyler Dr. Susanne Wolfrum Prof. Dr. Erick M. Carreira 《Angewandte Chemie (International ed. in English)》2016,55(7):2555-2558
We disclose the syntheses of (+)‐bromodanicalipin A as well as (±)‐fluorodanicalipin A. The relative configuration and ground‐state conformation in solution of both molecules was secured by J‐based configuration analysis which revealed that these are identical to natural danicalipin A. Furthermore, preliminary toxicological investigations suggest that the adverse effect of danicalipin A may be due to the lipophilicity of the halogens. 相似文献
980.
Structural Revisions of a Class of Natural Products: Scaffolds of Aglycon Analogues of Fusicoccins and Cotylenins Isolated from Fungi
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Dr. Ying Tang Dr. Yongbo Xue Prof. Guang Du Prof. Jianping Wang Prof. Junjun Liu Bin Sun Dr. Xiao‐Nian Li Prof. Guangmin Yao Dr. Zengwei Luo Prof. Yonghui Zhang 《Angewandte Chemie (International ed. in English)》2016,55(12):4069-4073
The reisolation and structural revision of brassicicene D is described, and inspired us to reassign the core skeletons of brassicicenes C–H, J and K, ranging from dicyclopenta[a,d]cyclooctane to tricyclo[9.2.1.03,7]tetradecane using quantum‐chemical predictions and experimental validation strategies. Three novel, highly modified fusicoccanes, brassicicenes L–N, were also isolated from the fungus Alternaria brassicicola, and their structures were unequivocally established by spectroscopic data, ECD calculations, and crystallography. The reassigned structures represent the first class of bridgehead double‐bond‐containing natural products with a bicyclo[6.2.1]undecane carbon skeleton. Furthermore, their stabilities were first predicted with olefin strain energy calculations. Collectively, these findings extend our view of the application of computational predictions and biosynthetic logic‐based structure elucidation to address problems related to the structure and stability of natural products. 相似文献