Modern NMR Approaches to the Structure Elucidation of Natural Products

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.

Antony J. Williams graduated with a BSc and PhD in chemistry from the University of Liverpool and University of London respectively. He subsequently became a Post-doctoral Fellow at the National Research Council in Ottawa and then an NMR Facility Director at the University of Ottawa. He has also worked as an NMR Technology Leader at Eastman-Kodak Company in Rochester and held a number of positions, including Chief Science Officer, at ACD/Labs. In 2007, he established ChemZoo, Inc and became host of ChemSpider, one of the primary internet portals for chemistry. ChemSpider was acquired by the Royal Society of Chemistry (RSC) in 2009 and Dr Williams is currently Vice-President of Strategic Development at the RSC. He presently holds an adjunct position at UNC-Chapel Hill and has been a member of the ACS since 1996.

Gary E. Martin graduated with a BS in Pharmacy in 1972 from the University of Pittsburgh and a PhD in Pharmaceutical Sciences from the University of Kentucky in 1975, specializing in NMR spectroscopy. He was a Professor at the University of Houston from 1975 to 1989, assuming the position of Section Head responsible for US NMR spectroscopy at Burroughs Wellcome, Co. in Research Triangle Park, NC, eventually being promoted to the level of Principal Scientist. In 1996 he assumed a position at what was initially the Upjohn Company in Kalamazoo, MI and held several positions there through 2006 by which time he was a Senior Fellow at what was then Pfizer, Inc. In 2006 he assumed a position as a Distinguished Fellow at Schering-Plough responsible for the creation of the Rapid Structure Characterization Laboratory. He is presently a Distinguished Fellow at Merck Research Laboratories.

David Rovnyak earned his BS from the University of Richmond, and his PhD studying high resolution NMR of quadrupolar nuclei at MIT. He transitioned to solution phase biomolecular NMR in postdoctoral work at the Harvard Medical School before joining the Chemistry Department at Bucknell University, where he has been recognized with Bucknell's Excellence in Teaching Award. He currently serves as Assistant Editor of Concepts in Magnetic Resonance. His lab pursues interdisciplinary topics in biophysical research including bile acid aggregation, methods in protein NMR, nonuniform sampling and small molecule profiling.