Both books are written in textbook style. Each book has its own strengths and weaknesses. For example, Enzymes is definitely not a beautifully-typeset book. On the other hand, the printing in Biotransformations, while nicer, is light and difficult to read. More importantly, both books omit major classes of reactions that could potentially be of immense value to chemists. Here is my biased, incomplete, and subjective summary of some of the reactions that I could find in each book:
|Synthesis of amides||√||√ (not in index)|
|Formation of hydroperoxides by oxygenases||√||in passing|
|Reactions of sterols / steroids||√||in passing|
|Cholesterol synthesis from squalene||no||√|
|Hydrolysis of nitriles||√||√|
|Synthesis of epoxides||√||√ (not in index)|
|Hydrolysis of epoxides||√||brief mention|
|Enantioselective reduction of ketones||√||√|
|Phosphorylation of alcohols by kinases||√||√|
|Microbial Baeyer-Villiger reactions||√||√|
|Aldol condensation (formation of C-C bonds)||√||√|
|Number of references in chapter on hydrolysis||684||361|
From this table, Biotransformations would appear to have a strong edge in most categories. Part of the difference lies in the much better index in Biotransformations. For example, in Enzymes, addition of O2 to lipids to form hydroperoxides is only indexed under "lipoxygenase" and not under "double bonds", "oxygen", or "hydroperoxides", while all of these are listed in Biotransformations. Biotransformations is also more complete, with better coverage and more references in most chapters. However, Enzymes seems to be better at covering the difficulties and drawbacks of the reactions. Enzymes also has more Larock-style tables showing examples of reactions. For my purposes, which was to learn how to use enzymes to form unusual amide bonds in a peptide, both books, as the kids say, totally sucked.
Enzymes are particularly good at catalyzing hydrolytic reactions. Unfortunately, as with any catalyst, the reaction runs in both directions, and the ratio of substrate to product is determined by their relative thermodynamic stability. Thus, the idea of using a protease in reverse to synthesize peptides as both books suggest, is not likely to win many converts. Nevertheless, for the growing class of pharmaceutical biomolecules, enzyme-catalyzed reactions are a useful tool that organic chemists should become more familiar with.