. The actinomycetes. Actinomycetales. CHEMICAL NATURE OF ANTIBIOTICS 57 has not been elucidated, but they are known to he formed of a large macrolide ring to which is attached mycaminose and my- , already found in the carbomycin molecule, and which in addition contains another amino sugar moiety of the following structure: CH3 N- CH3 CH3 -OH Longisporin is an antibacterial antibiotic, the complete structure of which is not known. Preliminary data indicate the exist- ence of a large multilactone ring (three lactone groups) of 36 carbons. A compound which is somewhat similar to the antiba
. The actinomycetes. Actinomycetales. CHEMICAL NATURE OF ANTIBIOTICS 57 has not been elucidated, but they are known to he formed of a large macrolide ring to which is attached mycaminose and my- , already found in the carbomycin molecule, and which in addition contains another amino sugar moiety of the following structure: CH3 N- CH3 CH3 -OH Longisporin is an antibacterial antibiotic, the complete structure of which is not known. Preliminary data indicate the exist- ence of a large multilactone ring (three lactone groups) of 36 carbons. A compound which is somewhat similar to the antibacterial macrocyclic lactones is nocardamine. It has an odd molecular struc- ture with a nine-membered ring with an ad- jacent three-membered ring. It has one weakly acidic and no basic center: OH. It is active only against mycobacteria. Streptomycins Streptomycin is active against gram-posi- tive and gram-negative bacteria and myco- bacteria. Its molecule is composed of three moieties—.streptidine, streptose, and X- methyl-L-glucosamine: C CHO Streptidine is a diguanido derivative of inositol. The hydrogenation of streptomycin under pressure, in presence of platinum oxide or palladium black, results in the reduction of the aldehyde group in the pentose, streptose. The resulting compound, which is biologically active and is chemically more stable than streptomycin, is called dihydro- streptomycin and can also be produced di- rectly by certain Strcptomyces. Another chemical transformation is the removal of an oxygen at the same site, with the forma- tion of : CHO—C—OH I Streptomycin I CH2OH—C—OH 1 )ihy(ho8treptoniycin —CH Streptomycin-producing strains of S. griscus form not only streptomycin but also a D-mannoside of streptomycin whicii was at first called streptomycin B and is now called The mannose moiety is attached, in the pyranose form, to the 4 position of the X-methyl-L- glucosam
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