Novel Compounds from Natural Products in the New Millenium, Potential and Challenges
Benny K.-H. Tan, Boon-Huat Bay and Yi-Zhun Zhu (editors), World Scientific Publishing Co., Singapore, 2004, xv + 319 pp., price £39/US$65, ISBN: 981-256-113-7This book is a collection of 30 papers that were given at the 2nd International Conference of the International Society for the Development of Natural Products held in Singapore in 2002. Although the chapters cover a number of topics, the majority are concerned with specific pharmaceutical applications of plant extracts and only in a few cases with purified natural products. A foreword by Kurt Hostettmann points out that only 10% of the world’s species have been investigated in a phytochemical and medicinal context, while there are new problems arising from the increasing significance of neurodegenerative diseases in an ageing population.
The first chapter by G. A. Cordell discusses the differing challenges of the global pharmaceutical companies, the bio-technology companies, the botanical supplement companies and the food industry developing nutraceutical agents, against a phytochemical background. This paper sets out the bureaucratic and ethical problems that must be overcome for the sustainable and equitable development of natural products as potential phytotherapeutic agents. The chapter on the bio-extraction industry in Jamaica exemplifies the challenges of conservation and sustainability in the commerical production of natural products. The effects of natural products on liver cytochrome P450s and the consequent modification to the metabolic patterns of synthetic drugs provides a warning of the potential interactions between some herbal and pharmaceutical remedies. The application of bio-informatics to natural products receives some consideration in several short chapters. A −1 ribosomal frame-shift is used in some forms of viral replication within a host cell. Application of this to a yeast-based system has led to the development of a method for the high-throughput screening of natural products for anti-viral activity. A chapter on botanical pesticides such as neem (Azadirachta indica) considers the integration of natural and synthetic compounds in pest management schemes, the relative efficiency of each, and the future for natural pesticides. The following chapter exemplifies this in the use of an extract of Jamaican ackee fruit in the control of cattle ticks and sweet potato weevils. A number of short chapters are more concerned with the pharmacology of plant extracts rather than the chemistry of their constituents. Although the biological activities of phytochemical extracts are described in detail, frustratingly the actual bio-active compounds are not often described. For example, the anti-cancer and immunomodulatory potential of an analogue of andrographolide is described but the compound concerned is only referred to by a company identification number, and no formula is given. The activity of the cruciferous product 1-cyano-2-hydroxy-3-butene (crambrene) in bringing about apoptosis of pancreatic cells and in the induction of detoxification enzymes is reviewed. The anti-oxidant and anti-hypertensive activity of sesamin forms the subject of several chapters, and the effects of apigenin on lipid peroxidation are also described. There are chapters on the tumour-inhibiting properties of lentinan, which is a glucan from the mushroom Lentinus edodes, and on turmeric and curcurmin in this context. The Chinese herb Salvia miltiorrhiza has a wide range of biological activities including a significant effect on acute myocardial infarcation in test animals. Although a large number of diterpenoid compounds have been isolated from this source in previous investigations, it was disappointing from the natural product chemist’s point of view that the paper here only described the effects of the crude herb. The final chapters in the book are concerned with funding and the protection of intellectual property rights.
The book is well-produced and each chapter contains a list of salient references. Many of the results that are discussed are tabulated or presented graphically and supported by a brief experimental section. However, the lack of structural formulae is not only frustrating but detracts from the value of the book to the natural product chemist. The title of the book is that of “Novel Compounds from Natural Products”, and the reader would therefore expect some structural detail of the compounds concerned. This was absent from many of the papers. There is an author index but no subject index. The omission of this is a pity because some topics, e.g. anti-oxidant activity, are covered from different angles in different sections of the book. Cross-references and comparisons are therefore difficult.
Nevertheless, this book is an interesting record of some pharmaceutical developments that are taking place with plant extracts at the start of the 21st century.
James R. Hanson
University of Sussex, Brighton, UK BN1 9QJ
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