PREFACE 



Chemistry is becoming more and more an essential tool for biological investigations. 

 Yet, although the biologist to be effective in many areas of study needs a strong knowledge 

 of chemistry, the kinds of things he needs to know are not necessarily the same things 

 which a chemist needs to know. In many ways the biologist's knowledge of chemistry 

 must be more comprehensive than the chemist's since he is usually unable to choose the 

 compounds which he must work with. They are presented to him in a bewildering variety. 

 On the other hand, the lifeblood of chemical investigations into natural products is made 

 up of degradations, proof of structure, and synthesis; none of these are usually of much 

 concern to the biologist. What the biologist wants to know is, "What sort of compound is 

 this which I have found to be involved in such and such a process; from what precursors 

 is it made, and what happens to it later?" The exact structure of a compound down to the 

 location of every double bond and the precise spatial configuration and conformation of the 

 atoms are problems which ultimately must be faced, but by a chemist rather than a biolo- 

 gist. Because of this difference between chemical and biological outlook, the wealth of 

 literature and courses on the chemistry of natural products seldom gives the biologist 

 satisfying answers to his questions, or else delivers these answers with effort and in the 

 midst of much extraneous information. There are multivolume and multiauthor works 

 which direct their discussions of the chemistry of natural products toward biologists, but 

 despite their enormous coverage and depth, even if the individual could afford to have 

 them all at his fingertips, he would find large gaps and unevenness in the information 

 which they provide. Certain classes of compounds are not adequately described, others 

 are well-treated per se but not contrasted with other types of compounds which they re- 

 semble or which are found in nature along with them. Sometimes detailed and elaborate 

 methods of characterization are given which are essential for laboratories engaged in an 

 intensive investigation of a certain type of compound but which merely frustrate an indi- 

 vidual who just wants to know if he has a compound of that type. It is for these various 

 reasons, and others, that this book was conceived. 



It may appear that we have given undue prominence to some relatively unimportant 

 classes of compounds. This has been intentional, and it is an important justification for 

 the book. A reader who desires general information about carbohydrates or amino acids 

 can turn to many excellent sources; but should he want to know something about naturally- 

 occurring lignans or acetylenes, he can at present find no discussion at a level of com- 

 plexity suitable for the interested non-specialist. 



It should be evident that we have intended to present a book of chemistry rather 

 than biochemistry. Although the metabolic interrelationships of compounds are summa- 

 rized, we have avoided the temptation to discuss the enzymology of these processes or 

 their place in the total picture of plant physiology. Nevertheless, a brief summary of 

 metabolic pathways should be helpful in orientation, and, if one compound has been found, 

 may point the way to finding others that may be associated with it. We have assumed that 

 the reader is familiar with elementary organic and biological chemistry. Many simple 

 concepts which are well covered in general textbooks of these subjects are therefore 

 omitted, assumed, or briefly referred to. 



While this book has been directed primarily toward botanists and pharmaceutical 

 chemists, perhaps by glancing through it organic chemists with an intensive knowledge 

 of one area or another will be brought to see an immense number of untouched problems 



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