J. Molyneux, eds. Boca Raton, FL: CRC Press; 2008. Hardcover; 605 pages. ISBN-13: 978-0849372582. $199.95.
Botanists estimate that only about half of the estimated 500,000 flowering plants have been botanically described, and of these, only about 10% have been chemically described, many in only a rudimentary way. While we often think of natural products as those derived from plants, there are a multitude of other organisms that are potential sources of bioactive compounds, such as yeasts, spider venom, and corals, to name only a few. These bioactive compounds include therapeutics (such as the penicillins), compounds toxic to humans or animals, and compounds useful for pest control. Considering the large number of biologically active chemical compounds discovered so far in the limited number of species investigated, there exists a vast opportunity to discover and develop new natural products.
Steven M. Colegate and Russell J. Molyneux address this opportunity in their book Bioactive Natural Products: Detection, Isolation and Structural Determination, a 600-page handbook covering all aspects of detecting, isolating, and determining structures of chemical compounds in natural products. The book is divided into 21 chapters, each written by a different research group, and promotes a multi-disciplinary approach, involving fields such as chemistry, biology, herbal medicine, toxicology, etc. It is geared towards those with a strong qualitative analytical chemistry background; those without such a background will probably find their eyes glaze over quickly at the multitude of 2-D NMR (2 dimensional nuclear magnetic resonance) spectra, chromatograms, and chemical structures. For those of us who are analytical chemistry geeks, however, the book provides a wealth of information on the identification and characterization of bioactive natural products.
The editors did a fine job of organizing the chapters into a cohesive book. The first chapter starts with techniques to identify bioactivity in plant extracts or individual compounds, as this is the starting point in any search for potentially useful compounds. Techniques for the detection of general bioactivity, such as the brine shrimp test, and starfish/sea urchin assay are described, as well as more specific tests for characteristics such as antibiotic activity, insecticidal activity, allelopathy (the action of a plant to secret toxic compounds that impede the growth of nearby plants competing for water, sunlight, etc.), and others. Once biologically active fractions are identified, techniques for the isolation, separation, and purification of individual compounds from these extracts are described.
The remaining chapters are broken into 2 different categories. There are 9 chapters dedicated to individual analytical techniques, including NMR spectroscopy (3 chapters), high-speed counter current chromatography, and liquid chromatography-mass spectrometry. Several of these chapters describe cutting-edge analytical technology, such as the chapters on LC (liquid chromatography)-NMR and biosensors. As a result, some of these techniques may not be easily accessible to many natural product laboratories, but it is always good to know what can be done, and the direction technology is going.
In addition to chapters dedicated to analytical techniques, there are 10 chapters on the identification and/or screening of compounds, either with specific biological activity, or from particular species. Some of these chapters are general, such as chapter 12, “Anticancer Drug Discovery and Development from Natural Products,” and chapter 21, “Plant-Associated Toxins: Bioactivity-Guided Isolation, ELISA (Enzyme-Linked ImmunoSorbent Assay), and LC-MS (Liquid chromatography-mass spectrometry) Detection.” Others are quite specific, such as chapter 16, “Bioassay-Directed Isolation and Identification of Antiaflatoxigenic Constituents of Walnuts,” and chapter 17 “Bioactive Peptides in Hen Eggs.”
The main strength of the book is the combination of general principles with very specific real-world examples. This enables natural products chemists to apply the principles outlined in the book to their own specific applications. Even for those analytical chemists not involved with the isolation and structural determination of natural products, the wealth of chemical structures, separation conditions, biochemical pathways, chemical degradation pathways, and NMR, MS, and UV (Ultraviolet-visible) spectra are a valuable resource. Want to know what the oxidative decomposition products of hyperforin are in St. John’s wort (Hypericum perforatum, Clusiaceae) and chromatographic conditions to separate them? It’s in there. Or the coumarins in the highly toxic Cicuta monnieri (Apiaceae) and a method of analysis for them? It’s in there. The detailed (21 page) index is also very helpful. The references at the end of each chapter are also extensive, with some chapters having over 300 references, mostly from peer-reviewed scientific journals.
Taken as a whole, Bioactive Natural Products: Detection, Isolation, and Structural Determination, would be an invaluable resource for those researchers involved with natural product chemistry, and it would also be very useful for those analytical chemists involved in the characterization of botanicals.