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Book Review Bioorganic Chemistry. A Chemical Approach to Enzyme Action. 2nd Edition. By H. Dugas

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BOOK R E V I E W S
Conformational Analysis of Medium-Sized Heterocycles. Edited by R.S . Glass. VCH Verlagsgesellschaft, Weinheim/
VCH Publishers, New York 1988. 274 pp., DM 126.00.ISBN 3-527-26789-110-89573-283-1
Is there a justification for a book which, in the form of a
collection of review articles, treats heterocycles with seven to
twelve atoms in the ring?
In a total of six chapters some well-known authors have
here attempted to give as complete as possible an overview of
this topic. Chapters 2-5 deal with heterocycles having 0, N,
S and P atoms in the ring, and in addition there is a chapter
on small cyclopeptides. The main emphases within the chapters reflect the interests of their authors, but it is apparent
throughout that an effort has been made to give as complete
a survey as possible, at least through the literature references.
Medium-sized aliphatic cyclic hydrocarbons can adopt
many different stable conformations, and consequently several conformers are present in equilibrium in solution or in
the gas phase. Nevertheless, the book makes it clear that in
heterocycles, and especially in partially unsaturated compounds, there are conformational restrictions which greatly
reduce the number of stable conformations.
In Chapter 1 , D.A. Case gives a concise review (30 pages)
of computational methods for determining conformations.
Quantum mechanical methods are still seldom applied to
medium-sized rings, partly due to the long computing times
involved (for ab znitio calculations), and partly because of the
uncertainty of the results obtained (for semiempirical methods). More space is given to force field calculations, where
D. A. Case describes, in summary at least, the most important force field computer programs, and tests their effectiveness using cyclooctane as an example. The data given on the
force fields in peptides are useful; however, the treatment of
Ramachandran diagrams as applied to alanine model dipeptides seems rather too detailed (even though it was of considerable interest to this reviewer), in view of the fact that on
other topics the reader is only given a few references to the
original papers (e.g. in the case of the “anomeric effect”). In
contrast the sections on the problem of multiple energy minima are well furnished with references, although here molecular dynamics calculations are treated rather too briefly.
In Chapter 2 E A. L. Anet first sets out definitions and the
conformational nomenclature for medium-sized rings, then
discusses cyclic hydrocarbons, followed by the additional
geometrical restrictions that are imposed on the rings by
oxygen atoms, sometimes combined with (partial) double
bonds. He then gives a survey of 0-heterocycles, arranged
Angew Chem Inr. Ed Engl 29 (1990) No. 7
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according to ring size, which is as complete as existing
knowledge allows. The general part of the chapter is systematically set out and makes easy reading; it provides a useful
introduction, not only to this chapter but also to the other
parts of the book.
In Chapter 3 R. W Alder and J: M . White deal with N-heterocycles, using a similar sequence. Especially noteworthy
are the sections on transannular interactions and bicyclic
N-heterocycles, which are the author’s special fields of interest. The conformations of sulfur-containing cyclic compounds, including studies using photoelectron spectroscopy,
are discussed by W N . Setzer and R.S. Glass in Chapter 4.
In general, however, spectroscopic methods are mentioned
only briefly in the rest of the chapters, without any detailed
discussion (Chapter 6 is an exception). Medium-sized rings
containing phosphorus (Chapter 5 by L. D. Quin) are found
less frequently, and could offer a large field of research in the
future. In particular few medium-sized rings containing CPC
units have so far been synthesized.
In Chapter 6 V: J: Hruby and P. S. Hillpresent a survey of
cyclic tri- and tetrapeptides, peptide antibiotics and disulfide
peptides. The chapter begins with a section on analytical
methods (NMR, CD, IR), describing the basic features of
these techniques as applied to the conformational analysis of
peptides. The exclusion of larger cyclopeptides seems rather
arbitrary, since these show the same conformational features, apart from the more frequent occurrence of cis-amide
bonds and cyclol formation in the small rings.
Thus the publishers are offering here a book which brings
together a heterogeneous area of knowledge from the viewpoint of ring size; this is done in such a way that, despite
having different authors, a consistent picture of conformations in medium-sized rings emerges. The book draws together, from many different areas of chemistry, a wealth of
information which it would not be easy to find by searching
the literature directly. It is recommended for use as a work
of reference by every chemist who seeks to control conformations in reactions, complexations or rearrangements, and
therefore needs to be concerned with medium-sized rings.
Martin Feigel [NB 1017 IE]
Institut fur Organische Chemie
der Universitat Erlangen-Nurnberg (FRG)
Bioorganic Chemistry. A Chemical Approach to Enzyme Action. 2nd Edition. By H. Dugas. Springer, Berlin 1989. xv,
651 pp., hard cover, DM 98.00.--ISBN 3-540-96795-8
Bioorganic chemistry reached a high point in the fifties
and sixties, mainly through the use of isotopes for elucidating biosynthetic pathways and enzyme mechanisms, but also
through chemical synthetic work mimicking biogenesis; in
the last few years it has been undergoing a powerful renaissance. The reason for this is a shift in research objectives,
with a greater emphasis now on investigating the factors
which influence biological processes, instead of merely aiming to describe the sequence of events, e.g. in terms of an
enzymic mechanism. Recently, there have been efforts to
gain a better understanding of the non-covalent interactions
which play the key role in all biological processes. A whole
new area of bioorganic chemistry that reaches far beyond the
original concept of enzyme chemistry has been opened up by
the magic phrase “molecular recognition”. During the last
Verlagsgesell.whafl mbH, 0-6940 Wemheim, 1990
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81 5
few years various monographs, some of them quite excellent,
have appeared dealing with different aspects of this topic
from a variety of viewpoints. With the publication of this
second edition of “Bioorganic Chemistry” we now have a
work which aims to treat the whole area in textbook style.
The same division of the material into seven chapters, as
in the first edition, has been retained. However, this is a very
coarse structure for the wide range of topics now covered,
and leads to some unexpected classifications, such as the
inclusion of the “suicide” deactivators in the chapter on coenzymes.
Chapter 1 provides a good introduction outlining some
basic principles, although it includes the misleading comment that bioorganic chemistry began only in the 1950s with
the work of E H . Westheimer (on this side of the Atlantic the
biomimetic syntheses carried out by Clemens Schopf and Sir
Robert Robinson in the twenties are still well remembered).
However, this discussion has been kept very short (22 pp.)
and consequently it is unavoidably superficial. The following
chapters on amino acids and peptides (86 pp.) and on phosphate esters and polynucleotides (60 pp.) not only treat these
topics comprehensively, from the basic features of peptide
and phosphate ester chemistry through to the biosynthesis of
the corresponding polymers, but also include interesting sections on newer and very recent developments such as catalytic antibodies, semisynthetic enzymes and DNA-intercalating
compounds. Chapter 4 (enzyme chemistry, 91 pp.) and
Chapter 5 (enzyme models, 136 pp.) form the core of the
book. In Chapter 4 the author first defines and explains the
use in this context of terms such as “catalysis” (although
even in this latest textbook we find the frequently used expression “intramolecular catalysis”, which is incompatible
with the definition of catalysis given earlier), “prochirality”
and “specificity”. Examples of actual enzyme reactions are
then discussed, followed by short sections on enzyme technology (including immobilization) and the increasingly important use of enzymes in organic synthesis.
The sections that are also included here on enzymeanalog-built polymers and on the construction of nonmacrocyclic molecular clefts could more appropriately have
been added to the next chapter on enzyme models. These
describe all the important strategies and design approaches
whose common denominator is the mimicking of biological
host-guest relationships. As well as recent developments
based on the now already classic cyclodextrin and crown
ether parent structures, the discussion also includes systems
without a precisely defined structure (functionalized polymers and micelle-forming species). Also noteworthy is the
treatment in this chapter of biomimetic reactions which, although they are models for biological specificity, do not need
a molecular host; these include polyene cyclizations and
functionalizations at non-activated steroid sites.
Chapter 6 is concerned with models that mimic the role of
metal ions in biological processes. The ions of the transition
metals Zn, Fe, Cu and Co are treated in turn; for these
artificial systems, some of which seem very contrived, the
ions are mainly introduced using porphyrin ligands. The
simulation, using cobalt complexes, of enzymic reactions
that depend on vitamin B,, links up with Chapter 7, which
is devoted to the chemistry of coenzymes. This classic field of
bioorganic chemistry is here subdivided according to the
functions and structures of the coenzymes (redox enzymes:
NAD, flavine etc.), and the most recent findings concerning
reaction mechanisms and model reactions are described by
means of well chosen examples. However, no reference is
made to the wide variety of new coenzymes obtained from
methanogenic bacteria (methanofuran, methoxatin, factor
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Verlagsgesellschaft mbH. 0-6940 Weinheim. 1990
F,,, etc.), for which details of the reaction mechanisms as
well as some model reactions are already known.
These omissions are not very serious when one considers
the wealth of information that is here very well presented, in
both textual and diagrammatic form. Nevertheless, it is clear
that the limitation of bioorganic chemistry to the chemistry
of enzymes, and therefore also the book’s subtitle, is obsolete
and does not adequately describe the subject.
“Bioorganic Chemistry” is certainly not a textbook in the
popular sense, as the emphasis is less on general principles
and “proven” knowledge than on illustration by examples.
This is no doubt intentional, and as a result the book makes
stimulating reading. However, one would have preferred the
author of such a textbook--especially one on an interdisciplinary topic like this-to be bolder in critically evaluating
the material and expressing his opinions. This applies especially to situations where there is controversy between alternative approaches, which are here simply not mentioned.
The reductionistic approximation for bioorganic systems,
although it is currently by far the most successful approach
to understanding the action of enzymes, is by no means the
only one, or even the only useful one.
Despite this criticism, H . Dugas has succeeded in producing a book which clearly describes the beauty and subtlety of
both living and abiotic molecular architecture. As well as the
readership for whom the book is mainly intended (1.e. advanced students), I can warmly recommend it to everyone
who seeks a comprehensive account, at a moderate price, of
current front-line developments in this highly topical field of
research.
Franz P . Schmidtchen [NB 1026 IE]
Lehrstuhl fur Organische Chemie und Biochemie
der Technischen Universitat Miinchen, Garching (FRG)
Fundamentals of Molecular Spectroscopy. By W S . Struve.
Wiley, Chichester 1989. 379 pp., hard cover, E 31.95.ISBN 0-471-85424-7
A good training in the fundamentals of molecular spectroscopy is important for all chemists and for many physicists and biologists. Several generations of young scientists
have grown up with Herzberg’s three-volume classic work
“Molecular Spectra and Molecular Structure”, Volume 1 of
which was originally published in German in 1939 (Molekiilspektren und Molekiilstruktur, Steinkopff Verlag). Herzberg’s books are still unsurpassed in scientific thoroughness
and depth of treatment. Moreover, it is pedagogic masterpiece because of the many well chosen examples and the
clear, usually simple, manner of presentation. However, the
third and last volume was published as long ago as 1966, and
since then the books have not been revised (except for the
publication of a supplementary volume of tables, K. P. Huber and G. Herzberg: Constants of Diatomic Molecules, van
Nostrand, 1979). Since 1966 great developments have taken
place in molecular spectroscopy. On the experimental side
Fourier transform spectroscopy and laser spectroscopy have
become well established, while on the theoretical side quantitative quantum chemical calculations have become possible,
developments which one could at best only have guessed at
in 1966. Thus, there has for some time been an urgent need
for up-to-date textbooks on molecular spectroscopy. This
has now been partly covered, e.g. by the textbooks of Kroto:
Molecular Rotation Spectra, Wiley, 1975, and Hollas: High
Resolution Spectroscopy, Butterworth, 1982, both of which
can be recommended in this context.
0570-0833~90/0707-0816S 03.50+.25/0
Angew. Chem. Int. Ed. Engl. 29 (1990) No. 7
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