Structure Elucidation Of Natural Products By Mass Spectrometry

This volume contains reviews which are based on a symposium, given th at the 30 meeting of The Phytochemical Society of North America, held at Laval University in Quebec City, Canada on August 11-15, 1990. During the past two decades, there have been major new developments in methods which can be applied toward the isolation, separation and structure determination of complex natural products. Therefore, the topic of this symposium, "Modem Phytochemical Methods", is a very timely one. The organizers of the symposium recognized that it would not be possible to cover in detail all new advances in phytochemical methodology. It was therefore decided to emphasize general reviews on recent developments of major separation techniques such as high performance liquid chromatography as well as supercritical fluid chromato graphy. In addition, advances in commonly used structure determination methods, mainly NMR and MS, are reviewed. Other topics include methodo logies of micro-sampling for isolation and analysis of trichome constituents as well as recent breakthroughs on biosynthetic studies of monoterpenes using "enriched" basal cells of trichomes. The volume concludes with a review of quantitative structure-activity relationship (QSAR) studies of biologically active natural products. In Chapter I, K. Hostettmann and his colleagues give a general review of recent developments in the separation of natural products with major emphasis on preparative separations of biologically active plant constituents. The authors present a comparison of droplet countercurrent chromatography (OCCC) with the highly rapid and more versatile centrifugal partition chromatography (CPC).

This book highlights analytical chemistry instrumentation and practices applied to the analysis of natural products and their complex mixtures, describing techniques for isolating and characterizing natural products. • Applies analytical techniques to natural products research – an area of critical importance to drug discovery • Offers a one-stop shop for most analytical methods: x-ray diffraction, NMR analysis, mass spectrometry, and chemical genetics • Includes coverage of natural products basics and highlights antibacterial research, particularly important as efforts to combat drug resistance gain prominence • Covers instrumental techniques with enough detail for both current practitioners and beginning researchers

The first volume in a two-part set that discusses contemporary NMR approaches for the structure elucidation of natural products. It covers optimized hardware and experimental approaches.

Written by experienced authors, this book presents numerous natural everyday products with a high range of structural diversity. Twenty natural products have been arranged in five sections, describing three alkaloids, five colored compounds, three carbohydrates and glycosides, seven terpenoids, and two aromatic compounds. Adopting a highly didactical approach, each chapter features a uniform structure: Background, in-depth information about isolation processes and structural characterization as well as a Q&A section at the end. Alongside the theoretical information many practical hints for the laboratory work are also included. A comprehensive overview of UV-, IR- and NMR-spectroscopy as well as mass-spectrometry for every exemplified compound is provided and the understanding of these methods is supported by concluding questions and exercises. Educating and entertaining, this full-color textbook turns the learning process into a real pleasure, not only for students in natural products chemistry but also experienced professionals.

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.

Although numerical data are, in principle, universal, the compilations presented in this book are extensively annotated and interleaved with text. This translation of the second German edition has been prepared to facilitate the use of this work, with all its valuable detail, by the large community of English-speaking scientists. Translation has also provided an opportunity to correct and revise the text, and to update the nomenclature. Fortunately, spectroscopic data and their relationship with structure do not change much with time so one can predict that this book will, for a long period of time, continue to be very useful to organic chemists involved in the identification of organic compounds or the elucidation of their structure. Klaus Biemann Cambridge, MA, April 1983 Preface to the First German Edition Making use of the information provided by various spectroscopic tech niques has become a matter of routine for the analytically oriented organic chemist. Those who have graduated recently received extensive training in these techniques as part of the curriculum while their older colleagues learned to use these methods by necessity. One can, therefore, assume that chemists are well versed in the proper choice of the methods suitable for the solution of a particular problem and to translate the experimental data into structural information.