Vol.  3  Iss. 3 The Chemical Educator © 1998 Springer-Verlag New York, Inc.

ISSN 1430-4171 http://journals.springer-ny.com /chedr S 1430-4171(98)03217-9

Biotransformations in Organic Chemistry: A Textbook by Kurt Faber. Springer, Berlin, 1997. ISBN 3-540-61688-8 (soft cover). pp (x) + 402.

Stereochemical transformations in organic synthesis have reached a level of sophistication that was once thought impossible, however there are still many problems to be solved involving yields, economics, resolution, stereospecificity, and stereoselectivity. In biological systems, stereochemical transformations apparently present few biosynthetic problems; this results from the complex and inherently chiral nature of enzymes.

Not surprisingly, biochemists and microbiologists have been using the biosynthetic potential of microbes and their enzyme preparations to achieve subtle or difficult transformations for many decades (for bond making, bond breaking, or the formation of stereocenters). It has taken some time for organic chemists to accept the utility of enzymes and microbes as synthetic agents. There are several reasons for this, not the least being the consensus that most enzymes will not function in anhydrous organic solvents, the favored reaction medium in synthetic organic chemistry (although this mind-set with respect to solvents is changing). Enzymes as synthetic agents are no longer the sole province of biochemists and microbiologists, but are now, albeit slowly, being accepted by organic chemists undertaking complex syntheses. The aim of this book is to bridge the gap between biochemists and organic chemists concerning the use of enzymes and microbes in organic synthesis.

The book is arranged in four major sections: introduction and background information, biocatalytic applications, special techniques, and a final chapter on the state of the art and outlook for biotransformations. There is also a series of useful appendices including commercial suppliers of enzymes, lipase preparations, and major culture collections.

The introductory chapter discusses the advantages and disadvantages of using biocatalysts in synthesis and continues with a brief discussion of enzymes and their modes of action. This latter part is brief by a biochemist's standards but would still be useful for an undergraduate in chemistry with little training in biochemistry; on the other hand, it is clearly not the author's aim to give a thorough discourse on enzyme theory.

 The second chapter is the largest in the book and deals in good detail with how enzyme preparations and microbes may be used in biotransformations in aqueous media. Many different classes of synthetic transformation are discussed, as well as their advantages and disadvantages. The subsections are well organized and flow in a logical fashion (for a biochemist and an organic chemist!). The author has clearly achieved his aim in this chapter because here there is a wonderful overlap of biochemistry, microbiology, and synthetic organic chemistry.

The third chapter is also large and comes as a breath of fresh air (to me) since it is concerned with the use of enzymes in organic solvents. Apart from enzyme stability in organic solvents, one of the main problems in using enzymes as catalysts, from an organic chemist's point of view, is the fact that the reagents are, more often than not, insoluble in water or aqueous buffers. In this chapter, the various techniques used to maintain enzyme stability in the presence of an organic solvent are discussed, for example, monophasic and biphasic systems, enzyme immobilization, and modified and synthetic enzymes.

The fourth and final chapter is short and discusses further possibilities for using enzymes in synthesis; in some ways this chapter is also a summary of what has been said in the book.

What do I think of the book? It is well thought-out. It is well written. It is well organized. It is unbiased: the author does not try to proselytize and convert organic chemists into biochemists. Organic chemists always will look for purely organic solutions to synthetic problems, as they should! This book should help organic chemists realize that enzymes are also organic reagents and are a useful adjunct to their synthetic armamentarium.

Has the author achieved his aims? I think so! Apart from the interesting (and from my point of view, exciting) detail and examples, I think that one of the main strengths of the book is its readability. Who would use this book? Biochemists, organic chemists, microbiologists, and pharmaceutical chemists (practicing in industry and/or research, postgraduate, or in the final year of a degree).