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Book Review Microbial Transformations of Steroids. By W. Charney and H. L. Herzog

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No dark reaction is observed. The rate of radical formation
in reactions (a)-(c) is always lower than that of the termination reactions (d) and (e). With the aid of known data for (d),
the rate of (b) could be represented in the form of the Arrhenius equation
kb = (7.1
-
1.0)~
106 exp-(10500
r 800)lRT 1 mole-1 sec-1.
Trans. Faraday SOC.65, 755 (1969) / -Hz.
[Rd 25 IEI
The structure of galvinoxyl [2,6-di-tert-butyl-4-(3,5-di-tertbutyl-4-oxo-2,5-cyclohexadienylidenemethyl)phenoxylJ( I ) ,
a stable phenoxyl radical, in the crystalline state has been
determined by D . E. Williams using X-ray diffraction. In the
crystal, the molecules are separated from one another by
normal van der Waals distances and have a twofold axis of
rotation. The CCC angle at the methine carbon atom is
134’, and the phenyl groups are twisted out of the plane of
conjugation by 12 in order to avoid interaction between the
two hydrogen atoms shown in formula ( I ) (separation
2.37 A). The CO bond length is 1.27 A and is thus intermediate between the values for C = O in aldehydes and ketones
(1.215 A) and C - 0 in phenols (1.36A). ’ Molecular Physics
16, 145 (1969)/ -HZ.
[Rd 26 IE]
Anexceptionallyreactive formofsilicagel is obtained, according
to C . Morterra and M . J. D . Low, when Aerosil is esterified
with methanol vapor a t 350 “C and the product is degassed a t
600-830°C. SiOH and SiH2 groups are formed on the
surface, which on prolonged heating and pumping off give
up hydrogen leaving Si radicals in the surface, which can be
detected by means of an ESR signal at g = 2.002.These
surface radicals are able to chemisorb molecular hydrogen
with dissociation, even at room temperature. SiOH and SiHz
are re-established via the SiH centers in the surface. Adsorbed
water does not react to any great extent with the surface silanes; they are stable towards oxygen up to 350 “C./ J. physic.
Chem. 73, 321, 327 (1969)/ -Hz.
[Rd 23 IE]
BOOK REVIEWS
The Refractory Carbides. By E. K . Storms. Vol. 2 in the Series
“Refractory Materials” edited by J. L. Margrave. Academic Press, New York, London 1967. 1 st Edit., xiii 285
pp.. 74 figs. and 83 tables; $ 12.50.
The author gives a good account of the chemical, physical,
and metallurgical properties of transition metal carbides that
are stable at high temperatures. Metal-carbide systems are
discussed on the basis of the literature in the case of Ti, Zr,
Hf, V, Nb, Ta, Cr, Mo, W, Th, U, and Pu. The discussion
comprises the preparation, phase relationships, lattice constants, crystal structure, appearance, chemical characteristics,
hardness, and thermodynamic properties. The last chapter
deals with these aspects in a more general manner. The
magnetic and electric properties of carbides are not discussed.
A subject index, an author index, and a bibliography, which
contains over 600 works and extends into 1966,complete the
book. This is an outstanding monograph and can be recommended to chemists, metallurgists, physicists, and
materials scientists.
J. Nick1
[NB 793 IE]
+
Microbial Transformations of Steroids. By W. Charney and
H. L. Herzog. Academic Press, Inc. New York-London
1967. 1st Edit., xi, 728 pp., $ 21.00.
Investigations o n the microbial transformations of steroids
were started some 30 years ago by Mamoli and VerceIlone.
At that time such reactions were primarily of theoretical
interest, and it was not until 1950,when results concerning
large-scale fermentation for the production of antibiotics
became available, that the subject received new, hitherto
undreamed-of impetus from Peterson and Murray’s discovery that progesterone is converted almost quantitatively by
molds into 1 la-hydroxyprogesterone, a readily accessible
starting material for the production of cortisone and hydrocortisone. Subsequently, hundreds of microorganisms were
investigated to establish whether they could promote steroid
reactions, and systematic studies of possible points of attack
on the steroid skeleton were carried out.
The present book has succeeded admirably in collecting the
results of these studies in tabular form, and covers the literature in its entirety, including United States patents, up to the
end of January 1964. Moreover, a large number of further
464
relevant scientific publications up to and including those
publishing in December 1966 are also cited.
The introductory chapter on historical developments is
followed by a n extremely lucid description of reactions of
steroids that can be carried with the aid of microorganisms:
1. Oxidation, 2. Reduction, 3. Esterification, Amide Formation, and Hydrolysis, 4. Isomerization, 5. Addition, Rearrangement, Elimination, 6. Asymmetrical Reactions, Resolutions of Racemates.
The main part of the book is taken up by two large tables.
The first one “Transformation by Products” (140 pages)
gives a list of the substances (arranged according to their
empirical formula) obtained from steroids by microbial reaction, as well as the type of reaction, yield, microorganism,
melting point, optical rotation, and literature reference.
A survey of the systematics of the microorganisms and of the
typical representatives for certain reactions is given in a number of smaller tables “Taxonomy” (40 pages). The book is
concluded by the largest table “Transformation by Genus”
(420 pages) in which the microorganisms used for steroid
reactions are arranged according to genus and subgroup
species. Sources for the strains, the steroid used as substrate,
the reaction performed, and the literature are all listed. The bibliography contains 1234 references.
The book is a mine of information for anybody who has
worked with microbiological reactions or intends to enter the
field, and is an invaluable aid in the laboratory. Even though
the literature has been considered only up to 1964,this does
not detract from the value of the work since very few substantially new results have been obtained in this field since
that time. Thus the book is an excellent survey and can be
recommended without reservation.
J. Schmidt-ThomP [NB 805 IE]
Wasserahnliche Losungsmittel (Water-like Solvents). By J.
Jander and Ch. Lafrenz. Vol. 3 of “Chemische Taschenbucher”, edited by W. Foerst and H . Grunewald. Verlag
Chemie GmbH., Weinheim/Bergstrasse 1968. 1st Edit.,
209 pp., 7 illustrations, 33 tables, D M 16.-.
The authors have chosen protic solvents as the first group
to be discussed: ammonia, hydrogen fluoride and higher
hydrogen halides, sulfuric and fluorosulfuric acid, acetic acid,
Angew. Chem. internat. Edit. 1 Vol. 8 (1969) / No. 6
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