Introductory 



Section B contains a compilation of the 

 basic information published on the anti- 

 biotics, as well as the antiviral and the 

 antitumor substances produced by actino- 

 mycetes. 



In presenting this information, emphasis 

 is laid upon the organism producing the 

 antibiotic; the method of extraction of the 

 antibiotic; its physical, chemical, and bio- 

 logical properties; its acti\'ity in riro; 

 toxicity; and practical utilization. A few of 

 the most pertinent references are gi\-en for 

 each antibiotic. 



The authors have tried to make a thorough 

 review of the literature up to July 1, H)()0. 

 After this date the coverage of the literature 

 has been more fragmentary. Specifically, 

 Section B contains: 



1. A compilation of the information avail- 

 able on the various antil)iotics. The sul)- 

 stances are arranged alphabetically. Anti- 

 biotics with no names, only numbers, appear 

 in the following order: first, those with no 

 letters before the numbers. The first digit 

 before which there is a break of some kind 

 gives the order of listing, for example, 

 antibiotic l-81d-ls will be foinid before 

 antibiotic 136. Second, the antibiotics 

 indicated by a letter with a number, such as 

 antibiotic F 416, are listed in alphabetical 

 and numerical order. Some antibiotics, 

 especially those which have been reported 

 very recently, will be listed at the end vmder 

 the heading "List of Additional Antibiotics." 

 Enough will be said in that section to suggest 

 the general nature of these substances. These 

 substances will be indexed but will not be 

 included in the keys and in the lists. 



2. Keys which might help those who try to 

 identify freshlv isolated antibiotics. It is to 



be understood that these keys are not classi- 

 fication systems, sensu strictu, but they are 

 presented here for the sole purpose of help- 

 ing the investigator who is interested in 

 characterizing antibiotic preparations. 



Antibiotics are first separated on the basis 

 of l)iological activity, then on the basis of 

 chemical properties. Special attention is 

 placed on the light-absorption spectra. Dif- 

 ferences in what one author might con- 

 sider a maximum of absorption and another 

 a shoulder could lead to confusion. The keys 

 lack uniformity because all aiitil)iotics have 

 not been described with equal care and ac- 

 cording to the same criteria. The same sub- 

 stance may, therefore, be listed in the keys 

 in more than one section. In spite of their 

 limitations, the keys have been useful to the 

 authors, and they hope that others will be 

 al)le to use them. 



o. A list of amino acids reported to be 

 present in hydrolysates of antibiotics. 



4. Lists of antibiotics active against proto- 

 zoa and viruses will be found after the keys. 

 A list of antitumor substances will also l)e 

 found there. 



One should note that antitumorsubstances, 

 with no known activity against microorgan- 

 isms, are not antibiotics as defined by the 

 senior author. For the sake of completeness, 

 we have tried to include such substances in 

 this book. 



The usefulness of this compilation is 

 extended by the index found at the end of 

 the A'olume, in which synonyms for the 

 antibiotics described are listed. 



In view of the rapidly accumulating in- 

 formation on antibiotics produced by ac- 

 tinomvcetes, and in view of the fact that the 



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