Chromatography of Antibiotics (Journal of Chromatography Library)
by: Gerald H. Wagman, Marvin Joseph Weinstein

Chromatography of Antibiotics (Journal of Chromatography Library)
By Gerald H. Wagman, Marvin Joseph Weinstein

Publisher: Elsevier Science Ltd
Number Of Pages: 247
Publication Date: 1973-10
ISBN-10 / ASIN: 0444411062
ISBN-13 / EAN: 9780444411068
CHROMATOGRAPHIC CLASSIFICATION OF ANTIBIOTICS
Over the years many investigators have devised numerous procedures for classification
and identification of antibiotics by use of chromatographic techniques. In earlier years,
these various chromatographc systems were quite usuable because of the relatively small
number of antibiotics compared to the present. With the thousands of antibiotics
currently known, systematic chromatographic classification of this large number of
compounds is extremely difficult. It is possible to group many of these substances, but in
order to identify very closely related antibiotics in a particular group the use of many
additional chromatographic systems may be required. This book is not written as a means
of systematic chromatography but hopefully as an aid in identifying very similar compounds
by use of specific chromatographic techniques. A number of methods proposed for
classification of antibiotics into groups and within groups will be reviewed for use in the
preliminary or presumptive identification of some of these compounds. More definitive
identification should be possible by selective use of the index comprising the body of the
book.
In 1959 Miyazaki et al. described a method of grouping antibiotics according to their
salting out chromatograms. The antibiotics were examined by means of ascending paper
chromatography. As solvents, distilled water and increasing concentrations of ammonium
chloride (0.5 to 20% and saturated solution) were used. Location of the antibiotic zones
were determined by bioautographic methods. Using this technique the antibiotics were
divided into four major groups. In group A the Rf values were not correlated with the
concentration of the ammonium chloride solution, identical values being found at all
concentrations and in distilled water. Group B consisted of the antibiotics which had an
Rf value of 0 in distilled water and increasing Rf values with increasing concentrations of
ammonium chloride. Group C displayed the highest Rf value in distilled water and lowered
values with increasing concentration of the ammonium chloride solution. G ~ o u pD
consisted of antibiotics which did not display any movement whatever in the solvent
from the starting point. This systematic method was extended by Uri’ who added two
additional groups. Group E consisted of antibiotics which had an Rf value of 0 in
distilled water and an initial increase with rising concentrations of ammonium chloride
with the maximum (Rf approximately 1) in 5% salt solution. Beyond this a decrease
occurred. This type of paper chromatogram was typical for the macrolides such as
oleandomycin, erythromycin, and carbomycin. Within the macrolide group further
differentiation was possible. An additional grouping, F, was made, which at that time
consisted of only one antibiotic, desertomycin. By connecting the Rf values using a
variety of concentrations of ammonium chloride solution paraboloid curves were obtained
which were different for different antibiotics.
Paris and Theallet3 were able to separate 23 antibiotics which were described in the
French Pharmacopia into seven groups utilizing paper and TLC as well as electrophoresis.
The groups were as follows: (1) penicillin and derivatives, (2) heterocyclic compounds
containing amino groups such as the aminoglycosides, (3) macrolides, (4) tetracyclines,
( 5 ) chloramphenicol and viomycin, (6) polypeptides, and (7) polyenes.
into five groups according to a chromatographic scheme.
Blinov and co-workers4 in 1969 were able t o separate over 300 antibacterial preparations
into five groups according to a chromatographic scheme.

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Triumph of the Heart: The Story of Statins
by: Jie Jack Li

Triumph of the Heart: The Story of Statins
By Jie Jack Li

Publisher: Oxford University Press, USA
Number Of Pages: 224
Publication Date: 2009-04-03
ISBN-10 / ASIN: 0195323572
ISBN-13 / EAN: 9780195323573

Product Description:

Over 25 million people in the U.S. alone have benefited from statins–such drugs as Lipitor, Zocor, Crestor, Pravachol, and other cholesterol-lowering medicines–in preventing stroke, heart attack, and other forms of coronary heart disease. But how did these remarkable, life-saving drugs come into being? In Triumph of the Heart, Dr. Jie Jack Li, a medicinal chemist and expert on drug discovery, tells for the first time the fascinating story of statins. Drawn from discussions with many scientists involved in the discovery and development of these drugs, the book illuminates the human side of science by revealing the role played by persistence, luck, and sudden insight that characterize major discoveries. For scientists in the drug industry, health care professionals, students of medicine, and all those intrigued by the basic human drive to explore and discover, Triumph of the Heart offers a compelling view of one of the most important drug discoveries of our time.

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