I have now finished my book about Natural Products and it is in production by Oxford University Press. The book is based on the lectures I gave to the final year students at the University of York but has been written for a broader audience. The theme of the book is thinking about Natural Products (NPs) and thinking about their role in all aspects of our life. As you can see from the chapter contents, the coverage is much broader than other books on NPs.
Nature's Chemicals: the Natural Products that Shaped our World
Richard D Firn
They make billions of tons of chemicals every year. They make hundreds of thousands different substances. Some of these chemicals, even in incredibly low doses, can kill organisms. All these chemicals are released into the environment and have been for hundreds of millions of years. Who is responsible? Not big business but plants and microbes and the chemicals concerned belong to a group called Natural Products (NPs).
NPs, which are largely unknown to the general public, are much more important in human affairs than the chemicals that most people know about - sugar, starch, proteins and fats. It is the NPs that have shaped, and continue to shape, the world. The trade in NPs has driven world history for 2 thousand years. Even now, in a world seemingly dominated by manufacturing, NPs still dominate human economic affairs.
Daily, every person spends a significant part of their time, and their income, seeking these chemicals without any awareness of the roles the NPs play in their lives. The caffeine in your tea or coffee, the theobromine in your chocolate and quinine in your tonic water are NPs. The smells and flavours of wine, most spirits and beer are due to their characteristic NP composition. You unconsciously choose your diet every day by selecting NPs that you find attractive - NPs give food the smells and taste that attract or repel consumers. Some humans become so attracted to NPs in plant products (tobacco, opium, cannabis, khat or cocaine) that they risk ill health or death by consuming them. A very few people even become addicted to NPs. However, some of the best antibiotics and anti-cancer drugs (penicillin, taxol, some synthetic steroids, vincristine) are all NPs.
Humans are in thrall to NPs. This book argues that an understanding of the properties and roles of NPs might help humans more fully understand the natural world, and their role in it. Given that millions of tons of NPs are made every day by plants and microbes, why don’t NPs accumulate in the environment? Why do only a very few of the many NPs we ingest every day harm us? Does this mean that natural chemicals are safer than synthetic chemicals? Is it true that humans should preserve natural habitats for the selfish reason that those habitats may contain organisms which will contain future generations of blockbuster drugs? These questions and others will be answered in this book.
Is this book for you?
Chemicals are very important to humans hence most humans have in their vocabulary some words that describe the major groups of natural chemicals - for example carbohydrates, proteins, fats and sugars. Many people know about amino acids and even DNA. Remarkably, however, few people know of the most important class of natural chemicals, the Natural Products, which I shall call NPs. Why is it remarkable that most people are so unaware of these chemicals? Simply because it is the NPs that are the key to understanding all manner of biological processes - how organisms attract or repel each other, how organisms choose their diet and habitat, how organisms breakdown ingested chemicals and why most ingested chemicals (synthetic or NPs) have no adverse effect on a consumer. Humans are no exception to this “control” by NPs. It is products rich in NPs, not products rich in protein, fats or carbohydrates that have dominated trade throughout human history. The Roman, Islamic and Western European empires were shaped more by their quests for NPs than their search for basic foods or minerals. Why did Islam spread to the Indian subcontinent and east to Indonesia? Why were the Portuguese, Spanish, Dutch and British colonies located where they were? Why did Venice gain such power and have such a flourishing culture? Was it co-incidence that the great blossoming of Islam culture flourished when Muslim traders controlled the flow of NP-rich spices to the European markets. Where did the wealth come from that made Amsterdam once of the richest cities in the world in the 16th C. with a flourishing culture interested in the arts, science and medicine? The answer to all these questions is that the human obsession with NPs have shaped history. Even at the start of the 21st C, most people are unaware of the fact that the trade in NP-rich commodities still dominates the world.
Despite this importance in world affairs, NPs attract little interest and most people know little about NPs. Yet every person is influenced by NPs every day of their lives. Every reader of this page will have unknowingly ingested hundreds of NPs in their food and drink during the last few hours. Every reader will have sought out certain NPs, and purposely avoided others, during the last 24 h. Some readers will have purposefully sought to change their behaviour recently by exposing themselves to some particular legal and illegal NPs. As will be explained, if one can understand why and how organisms make NPs, and if one can appreciate how other organisms have evolved to deal with NPs to which they are exposed, it is easier to understand how the world works.
So is this book for you (or someone you know!)? If you are interested in the answers to any of the following questions you might find this book helpful (the chapter numbers where answers are given are shown).
Questions that this book will answer
1. If NPs are so important, why do I know so little about them (Chapter 1)?
2. How did NPs influence Roman, Islamic, Asian, African, South American, North American and Western European history (Chapter 2)?
3. Why is a kg of coffee so much more expensive than a kg of flour to produce (Chapter 2)?
4. Why does the Pacific Yew tree make Taxol, the most important anticancer drug? Will an answer to this question help us discover new drugs (Chapter 7)?
5. Is it true that the human obsession for NPs still fund the largest economic activities in the world (Chapter 2)?
6. Are synthetic chemicals different from chemicals made by organisms? Are natural chemicals inherently safer than synthetic ones (Chapter 3)?
7. How can organisms make so many complex chemicals that humans find so hard to make (Chapter 3)?
8. Why do only a few synthetic chemicals build up in the environment (Chapter 7)? Why does a knowledge of NPs explain this?
9. Is the next miracle cancer cure more likely to be found in the rainforest or in the soil in your garden (Chapter 7)?
10. What happens to the thousands of NPs you eat every day? Why don’t these chemicals harm you (Chapter 7)?
11. If we can appreciate how NPs in your diet are handled by your body, will that help us understand how the body copes with synthetic chemicals like pharmaceutical drugs and pesticides (Chapter 7)?
12. What drives biochemical evolution? Why does one plant species make morphine but another plant makes the scent of orange blossom (Chapter 9)?
13. Will the genetic manipulation of the NP chemistry of plants be predictable? Does it matter (Chapter 10)?
If the author succeeds in his ambition, readers of this book will look at the natural world and human activities with fresh eyes. NPs have been the key to the evolution of the living world and one only has to look at the human affairs to see how human societies have evolved in response to these remarkable chemicals.
The structure of the book
The study of NPs was never a unified subject and the existing literature on NPs is scattered across many books and journals. Such dispersal of information might be one reason why NPs are seriously under appreciated. This book is an attempt to provide a synthesis from these dispersed sources, a synthesis that will inform and interest non-specialists. The chapter structure is just one of many that could have been adopted. Readers with some knowledge of the subject material may reasonably read one chapter out of order or they might even choose to miss some chapters completely, depending on their own interest. However, a reader coming to any one of the later chapters will need to know some core concepts introduced in the earlier chapters if the arguments we develop are to be appreciated.
Some knowledge of chemistry, maybe the equivalent of the advanced school chemistry, would make some chapters easier to understand but other chapters need very little knowledge or understanding of chemistry.