NMR Case Studies


Book Description

NMR Case Studies: Data Analysis of Complicated Molecules provides a detailed discussion of the full logical flow associated with assigning the NMR spectra of complex molecules, also helping readers further develop their NMR spectral assignment skills. The robust case studies present the logic of each assignment, from beginning to end, fully exploring the available range of potential solutions. Readers will gain a better appreciation of various approaches and develop an intuitive sense for when this particular concept should be implemented, thus enhancing their skillsets and providing a host of methodologies potentially amenable to yielding correct assignments. Authored by a scientist with more than 20 years of experience in research and instruction, this book is the ideal reference for anyone in search of application-based content. The book addresses complicated molecules, including corticosteroids, biomolecules, polypeptides, and secondary metabolites. Features the nuclear magnetic resonance (NMR) spectra of a number of large and interesting molecules, ranging from corticosteroids, to secondary metabolites and large synthetically prepared molecules Uses case studies to pair the spectral signals from the various sites of each molecule to their molecular counterparts in a process called assignment Includes complex NMR problems, aiding readers in the development of NMR spectral assignment skills Features input from a leading scientist with over 20 years of research and instruction experience in the field




200 and More NMR Experiments


Book Description

This work-book will guide you safely, in step-by-step descriptions, through every detail of the NMR experiments within, beginning with 1D routine experiments and ending with a series of advanced 3D experiments on a protein: ? Which experiment can best yield the desired information? ? How must the chosen experiment be performed? ? How does one read the required information from the spectrum? ? How does this particular pulse sequence work? ? Which other experiments give similar information? This third edition of the book, following its two highly successful predecessors, has been revised and expanded to 206 experiments. They are organized in 15 chapters, covering test procedures and routine spectra, variable temperature measurements, the use of auxiliary reagents, 1D multipulse experiments, spectra of heteronuclides, and the application of selective pulses. The second and third dimensions are introduced using pulsed field gradients, and experiments on solid state materials are described. A key part describes 3D experiments on the protein ubiquitin with 76 amino acids. What is new in this third edition? 1. 24 new experiments have been inserted into the 14 chapters that were in the 2nd edition, e.g., alpha/beta-SELINCOR-TOCSY, WET, DOSY, ct-COSY, HMSC, HSQC with adiabatic pulses, HETLOC. J-resolved HMBC, (1,1)- and (1,n)-ADEQUATE, STD, REDOR, and HR-MAS. 2. 20 new protein NMR experiments have been specially devised and are collected in the newly added Chapter 15, ProteinNMR, for which one needs a special model sample: fully 13C- and 15N-labeled human ubiquitin. Techniques used include the constant time principle, the PEP method, filters, gradient selection, and the echo/anti-echo procedure. The guide has been written by experts in this field, following the principle of learning by doing: all the experiments have been specially performed for this book, exactly as described and shown in the spectra that are reproduced. Being a reference source and work-book for the NMR laboratory as well as a textbook, it is a must for every scientist working with NMR, as well as for students preparing for their laboratory courses




Modern NMR Approaches to the Structure Elucidation of Natural Products


Book Description

The Ghanian plant Cryptolepis sanguinolenta is the source of a series of fascinating indoloquinoline alkaloids. The most unusual member of this alkaloid series was initially proposed to be a spiro nonacyclic structure, named cryptospirolepine, and was elucidated in 1993 based on the technologies available at that time. There were, however, several annoying attributes to the structure that bothered analysts for the ensuing 22 years. During the two decades that followed the initial work there have been enormous developments in NMR technology. Using new experimental approaches, specifically homodecoupled 1,1- and 1,n-HD-ADEQUATE NMR experiments developed in 2014, the structure of only a 700 µg sample of cryptospirolepine has been revised and is shown on the cover of this volume. The confluence of the NMR technological and methodological advances that allowed the revision of the structure of cryptospirolepine using a submilligram sample seems a fitting example for this book, which is dedicated to the NMR characterization of various classes of natural products. Volume 2 considers data processing and algorithmic based analyses tailored to natural product structure elucidation and reviews the application of NMR to the analysis of a series of different natural product families including marine natural products, terpenes, steroids, alkaloids and carbohydrates. Volume 1 discusses contemporary NMR approaches including optimized and future hardware and experimental approaches to obtain both the highest quality and most appropriate spectral data for analysis. These books, bringing together acknowledged experts, uniquely focus on the combination of experimental approaches and modern hardware and software applied to the structure elucidation of natural products. The volumes will be an essential resource for NMR spectroscopists, natural product chemists and industrial researchers working on natural product analysis or the characterization of impurities and degradation products of pharmaceuticals that can be as scarce as natural product samples.




NMR and MRI of Electrochemical Energy Storage Materials and Devices


Book Description

The aim of this book is to introduce the use of NMR and MRI methods for investigating electrochemical storage materials and devices to help both NMR spectroscopists entering the field of batteries and battery specialists seeking diagnostic methods for material and device degradation.




Dynamic Studies Through Control of Relaxation in NMR Spectroscopy


Book Description

Nicola Salvi's thesis offers a remarkably cogent view of highly sophisticated NMR methods. Salvi developed these methods in order to characterize the amplitudes and frequency ranges of local motions in biomolecules such as proteins. These local motions play an essential role since they can explain many of the remarkable properties of proteins and enable them to carry out all sorts of vital functions, from enzymatic catalysis to intermolecular recognition and signalling in cells. Salvi's work has led to numerous publications in high-impact journals.




Diffusion and Electrophoretic NMR


Book Description

Diffusion and Eletrophoretic NMR experiments resolve chemical compounds based on their molecular motion. This publication introduces the basics of these methods and explains how they can be used to measure the size of molecules and aggregates, to determine degree of polymerization and to solve other chemical problems. Supplied with many case studies, the book is a must-have for students and researchers who work with practical NMR measurements.




Experimental Pulse NMR


Book Description

This book is about pulse nuclear magnetic resonance (NMR), with its techniques, the information to be obtained, and practical advice on performing experiments. The emphasis is on the motivation and physical ideas underlying NMR experiments and the actual techniques, including the hardware used. The level is generally suitable for those to whom pulse NMR is a new technique, be they students in chemistry or physics on the one hand and research workers in biology, geology, or agriculture, on the other. The book can be used for a senior or first year graduate course where it could supplement the standard NMR texts.




LC-NMR


Book Description

The isolation and structural characterization of substances present at very low concentrations, as is necessary to satisfy regulatory requirements for pharmaceutical drug degradants and impurities, can present scientific challenges. The coupling of HPLC with NMR spectroscopy has been at the forefront of cutting-edge technologies to address these issues. LC-NMR: Expanding the Limits of Structure Elucidation presents a comprehensive overview of key concepts in HPLC and NMR that are required to achieve definitive structure elucidation with very low levels of analytes. Because skill sets from both of these highly established disciplines are involved in LC-NMR, the author provides introductory background to facilitate readers’ proficiency in both areas, including an entire chapter on NMR theory. This book provides guidance in setting up LC-NMR systems, discussion of LC methods that are compatible with NMR, and an update on recent hardware and software advances for system performance, such as improvements in magnet design, probe technology, and solvent suppression techniques that enable unprecedented mass sensitivity in NMR. It also describes numerous NMR collection strategies, including continuous flow, stop flow, solid phase extraction (SPE), loop collection, and capillary electrophoresis. In addition, the author presents an overview of NMR experiments and techniques used in structure elucidation. The text focuses on current developments in chromatographic-NMR integration, with particular emphasis on utility in the pharmaceutical industry. Applications include trace analysis, analysis of mixtures, and detection of degradation products, impurities, metabolites, peptides, and more. The text discusses novel uses and emerging technologies that challenge detection limits as well future directions for this important technique. This book is a practical primary resource for NMR structure determination—including theory and application—that guides the reader through the steps required for isolation and NMR structure elucidation on the micro scale.







Case Studies in Superconducting Magnets


Book Description

The 2nd edition emphasizes two areas not emphasized in the 1st edition: 1) high-temperature superconductor (HTS) magnets; 2) NMR (nuclear magnetic resonance) and MRI (magnetic resonance imaging) magnets. Despite nearly 40 years of R and D on superconducting magnet technology, most areas, notably fusion and electric power applications, are still in the R and D stage. One exception is in the area of NMR and MRI. NMR magnets are very popular among chemists, biologists, genome scientists, and most of all, by drug manufacturers for drug discovery and development. MRI and NMR magnets have become the most successful application of superconducting magnet technology and this trend should continue. The 2nd edition will have new materials never treated formally in any other book of this kind. As with the 1st, most subjects will be presented through problem format to educate and train the designer.