Book Reviews

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Supported Catalysts and their Applications

Ed. D. C. Sherrington and A. P. Kybett, Royal Society of Chemistry, Cambridge, x + 268 pp., price £69.50, ISBN 0-85404-880-4 Search PubMed“Supported Catalysts and their Applications” contains the proceedings of the 4^th International Symposium on Supported Reagents and Catalysts in Chemistry held on 2–6 July 2000 at the University of St Andrews, UK. From the title it is not immediately apparent that the book is a conference proceedings rather than a textbook. It contains 31 written forms of the 70 contributions to the symposium and is representative of the coverage of the meeting, the editor says in his preface. The focus of the book is on inorganic oxide materials modified with organic ligands in an attempt to construct well-defined metal complexes immobilised on the inorganic materials. The main goal of the contributors seems to be immobilisation of well-known catalysts to solve the problem of separation of catalyst and product or to achieve high yields as in solid-phase synthesis.

As one might expect the coverage and quality of the 31 contributions varies enormously. It would not be fair to point out specific weaknesses of particular contributions and instead I will try to present general information that might be useful. About half of the contributions originate from the UK, France coming in second place, and only 2.5 contributions are from outside Western Europe, while in the literature a large number of contributions to this field stems from Russia and Japan. This is not necessarily a drawback, as the articles may still cover a sufficiently broad area. Only 1.5 contributions are from industry; this could be understood as lack of confidence in this research by industry, which showed much more interest in this field some 30 years ago. Applications in petrochemicals have always suffered, and still do, from metal leaching and catalyst instability and no industrial applications have emerged to my knowledge. Using the present state of the art, however, one could considerably improve the old results.

Most contributions focus on fine chemicals or applications in organic syntheses, about ten are related to bulk chemicals and a few are concerned with oil or gas research. Oxidation occurs most frequently as the reaction studied, although two studies are concerned with the chemistry of carbon monoxide. Many of the fine-chemical contributions are very up-to-date using modern catalysts with references up to 2000. I also counted around seven contributions with references going back to 1998 (or even 1995) as the most recent ones. The number of references also varies between 7 and as many as 85 and the size of the contributions runs from 5 to 18 pages. A few contributions are of a review nature and superficial, but the majority describe a good mix of introductory text and recent results. Many recent advances are at least touched upon, such as supercritical media, ionic liquids, fluorous phase catalysis, metal triflates, strong bases, etc. While “separation” seems to be a key driving force for this work, it has been rarely studied or mentioned explicitly in the result parts of the contributions.

Two thirds of the articles discuss indeed the attachment of organic fragments to inorganic supports (a few studies are on polymer supports, an area studied more frequently in the past), but about one third are restricted to modified inorganic oxides. For the conference this was a good decision, I think, because the workers in this field are the experts that bring in the knowledge on characterisation of the solids, which is often neglected by the experts with an organic or organometallic background.

An area that I missed is that of alkene polymerisation using metallocenes for instance, which is an area where industry could have contributed to the symposium. Another related area that is missing is that of silsesquioxanes; both the solution organometallic chemistry and their immobilisation are intriguing, but perhaps it is just a little bit too early to be included in a conference that has “Applications” in its title. A mature area is that of solid-state organic syntheses, and although it has been addressed a couple of times, I would have welcomed more contributions, including one on combinatorial applications. Immobilization of enzymes represents another area that could have been included. Some of the missing topics can be found in a related RSC book (1998), Supported Reagents and Catalysts in Chemistry, edited by B. K. Hodnett et al.

In general the layout and readability is good, but in a number of instances the direct reproduction of overhead sheets into figures should have been discouraged. Several figures are ill reproduced and many diagrams and spectra use too much space. In many instances I found the letter size too small.

“Supported catalysts” is a rapidly moving field and a lot will be gained when the interactions between the experts in as yet different fields are intensified. Both the conference and this book contribute to this. A conference proceedings is not the best way to promote a field, I regret to say. A special issue, by invitation, of a review journal could solve some of the drawbacks I mentioned above and also ensure a more rapid publication.

Piet van Leeuwen
Universiteit van Amsterdam

Solution manual to accompany ‘Organic Chemistry’, by Clayden, Greeves, Warren and Wothers

Stuart Warren, Oxford University Press, Oxford, 510 pp., price £18.99, ISBN 0-198-70038-5 Search PubMedOne of the first principles of learning anything, be it golf or organic chemistry, is practice. Throughout my academic career I have collected aids to practising organic chemistry and have utilised them both in learning new subjects personally and in teaching others. A new addition to the fold is always of interest therefore.

Those who have had the privilege to have been taught by Stuart, or like me only to have heard him lecture, will already be aware of his superb didactic approach. Something of that magic has been distilled into this delightful volume of problems [from the textbook] with their thoroughly expounded solutions. The style and language is always clear, beautifully presented, encouraging and inspirational even. This accompanying manual is an outstandingly useful and valuable teaching aid in its own right. It should prove an excellent basis for tutorial exercises or a self-help to the serious student of Organic Chemistry. Those who have been brought up to be spoon-fed should be weaned off by being encouraged to tackle a regular dose of problems from this book.

Each chapter has generally 12–14 problems, the purpose of each of which is firstly explained followed by a suggested solution (or two), with extra notes and references if appropriate in the margin. As with the textbook, it is remarkably free of errors (but t-butylbenzene is one word!—page 3. At least he is consistent—the same type of error is in the textbook—page 39). I cannot recommend this book too strongly. It is the best of its kind that I have seen, particularly for UK students and teachers of Organic Chemistry.

Otto Meth-Cohn
Sunderland University

Solid Support Oligosaccharide Synthesis and Combinatorial Carbohydrate Libraries

Ed. Peter H. Seeberger, Wiley-Interscience, New York, xii + 308 pp., price £71.50, ISBN 0-471-37828-3 Search PubMedOligosaccharides are the last type of biopolymer that is still challenging to synthesise. While oligonucleotides and peptides are routinely made in non-specialist laboratories using solid phase synthesis machines, a similar method for oligosaccharide synthesis is lacking. In the last decade many laboratories have taken on the task to try to solve the difficulties associated with solid phase oligosaccharide synthesis and exciting progress has been made. The book, edited by Peter Seeberger, gives an overview of the progress that has been made in solid phase oligosaccharide synthesis over the last 10 years, and also covers related combinatorial chemistry techniques.

The book is divided into 14 chapters written by authors from leading laboratories engaged in solid phase synthesis of carbohydrates or related topics. In general each chapter describes a methodology developed by the author's laboratory, and in fact gives quite a good impression of the state of the field. The editor himself has together with collaborators contributed three chapters: a chapter about solid phase oligosaccharide synthesis using glycosyl phosphate donors, a chapter about the special analysis techniques that are used in solid phase synthesis (a useful inclusion indeed for newcomers in the field), and a chapter about the history of solid phase oligosaccharide synthesis. The latter gives a fairly faithful account of the history of the field from its absolute beginning in 1971 until 1991.

The book further contains a series of chapters that reports on the use of different glycosylation methods in solid phase synthesis. Thus Cirillo and Danishefsky report on solid phase oligosaccharide synthesis using glycals, Taylor writes about sulfoxide based glycosylations, Knerr and Schmidt discuss the use of glycosyl trichloroacetimidates in solid phase oligosaccharide synthesis, and Wittmann reports on the similar use of thioglycosides and pentenyl glycosides. Ito and Ando report on β-mannoside synthesis on the solid phase using intramolecular glycosylation. A number of chapters deal with special oligosaccharide synthesis techniques that can be considered related to solid phase synthesis: Krepinsky and Douglas describe polyethylene glycol supported solution phase synthesis of oligosaccharides, Boons and Zhu write about “two-direction” glycosylations, Simanek and Wong report on one-pot glycosylation procedures in solution and Kanie and Hindsgaul on the synthesis of oligosaccharide libraries using random glycosylation in solution. Finaly there are two chapters on glycopeptide synthesis: one by Kunz and Bezay and another by St. Hilaire, Halkes and Meldal.

Overall the book is to be recommended to those who wish to enter the field, as it provides a fast access to a collection of important developments. It also gives a splendid overview over the state of the art of the field. Perhaps the only drawback is that it, like many other multiauthor books, tends to give an uncomprehensive coverage of the field because each author gives an account of his own work only including the work of direct competitors.

Mikael Bols
Aarhus University, Denmark

Enzyme Technologies for Pharmaceutical and Biotechnological Applications

Herbert A. Kirst, Wu-Kuang Yeh and Milton J. Zmijewski, Jr, Marcel Dekker, US, xv + 611 pp., price $195, ISBN 0-8247-0549-1 Search PubMedThis is an interesting book in that the editors have achieved the difficult task of combining broad coverage with an in depth treatment of individual topics. The linking theme, as revealed in the title of the book Enzyme Technologies for Pharmaceutical and Biotechnological Applications, is really the impact that current research on enzymes is having on areas of scientific research in industry and universities. An advantage of casting the net wide in this way is that although the reader may initially be drawn to chapters of direct relevance to his/her own research, further browsing is likely to reveal topics that stimulate lateral thought and promote new insight. The authors are to be commended for taking upon themselves such an ambitious project given the total number of contributions (24 chapters) from an international group of research teams.

The book is divided into four sections entitled ‘Biosynthesis’, ‘Biocatalysis’, ‘Screening/Optimisation’ and ‘Emerging Technologies’, with the last topic being the largest section. For ‘Biosynthesis’, three of the five chapters deal with enzymes involved in the production of β-lactam antibiotics including ACV synthetase (Chapter 1: van Döhren et al.), cephalosporin C production (Chapter 2: Queener et al.) and the ring expansion of penicillins to cephalosporins (Chapter 3: Demain et al.). Each of these reviews is authored by acknowledged leaders in the field and provides a compelling introduction to the authority of the book. The section concludes with essays on fermentation of acyltylosins (Chapter 4: Arisawa et al.) and production of avermectins from a group of scientists at Pfizer, Groton, USA.

Section II deals with ‘Biocatalysis’ and is the smallest of the four parts of the book. In Chapter 6, Ramesh Patel from Bristol-Myers Squibb gives an impressive overview of the ways in which his group have applied biocatalysis to solved synthetic challenges in the discovery and development of novel drug substances. Chapter 7 (Stewart et al.) provides a timely review of our current knowledge concerning various ketone reductases from Saccharomyces cerevisiae which are useful enzymes for preparing non-racemic chiral secondary alcohols. In Chapter 8 Michael Grimm traces the development of cross-linked enzyme crystals (CLC's) from their initial preparation in 1964 to the recent work of Altus Inc., who have commercialised this technology. Finally Cockshott et al. from Eli Lilly describe work on the deacylation of echinocandins and related antifungal agents.

Section III addresses a series of topics grouped under the heading of ‘Screening/Optimisation’. Here we are taken through recent developments in technology for screening therapeutic enzymes, particularly employing high-throughput methods. After an initial overview of enzymes as targets for anti-bacterial drug discovery (Chapter 10: Roychoudhury) subsequent chapters focus on penicillin-binding proteins (Chapter 11: Zhao et al.), UDP-N-acetylmuramoyl-alanine: D-glutamate ligase (Chapter 12: Smith et al.), human rhinovirus proteases (Chapter 13: Wang et al.), parasiticides (Chapter 14: Geary et al.), enzymes involved in lipid metabolism (Chapter 15: Tomada et al.) and finally the phospholipase A₂ superfamily (Chapter 16: Yang et al.). With the rapid acceleration in the discovery of novel enzyme targets for intervention and inhibition, this section provides an excellent overview of the current state-of-the-art.

The final section on ‘Emerging Technologies’ is inevitably diverse in its subject matter and includes several highly contemporary themes. The first two chapters deal with the tremendous recent advances that have been made in our knowledge of polyketide synthesis and how these enzymes might be applied for the ‘combinatorial biosynthesis’ of bioactive unnatural products (Chapter 17: Khosla et al., Chapter 18: Staunton et al.). A related topic is explored in Chapter 19: (Glinski et al.), namely the use of in vitro enzymatic systems for the synthesis of cyclopeptides (e.g. cyclosporin) and depsipeptides. The final five chapters bring the reader right up to date with emerging ‘omic’ technologies including genomics and proteomics. Specific topics addressed are: new strategies for using enzymes in high-throughput screens (Chapter 20: Trias et al.), genomics in enzyme-based drug discovery (Chapter 21: Schmid), assigning precise functions to genes (Chapter 22: Chen), redesigning enzymes (Chapter 23: Chen) and 2D-gel electrophoresis coupled with mass spectrometric detection (Chapter 24: Krishnan et al.).

Notwithstanding the potentially enormous range of topics to choose from, the editors have done an excellent job in bringing to the attention of the reader most, if not all of the current ‘hot topics’ in enzyme biotechnology. This collection of reviews is very timely in view of the almost bewildering rate at which modern advances in molecular biology, analytical chemistry and robotic instrumentation make major impacts on all areas of protein science, including enzyme biotechnology. Finally, the book is attractively presented and contains refreshingly few typographical errors. Postgraduate or postdoctoral scientists either entering this field for the first time or wishing to expand their knowledge will find much of interest within the 600 pages of text.

N. J. Turner
University of Edinburgh, UK

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