Antibiotics, carbohydrate component

Carbohydrate Components of Antibiotics. Part II. Alkaline Degradation of Mycaminose and Synthesis of 3,6-Dideoxy-3-dimethylammo-L-altrose and Derivatives Therefrom, A. B. Foster, J. Lehmann, and M. Stacey, /. Chem. Soc., (1962) 1396-1401. 

It has been stated previously that the carbohydrate components of antibiotics have proved particularly amenable to analysis by n.m.r. spectroscopy. Thus, the structures of chalcose, desosamine, mycarose and cladinose have been established by n.m.r. spectroscopy. To this list may be added oleandrose, chromose " and arcanose. By making suitable model compounds it was possible to show that in oleandomycin, L-oleandrose exists in a 1-C conformation and has a a-L- linkage, whereas D-desosamine exists in a C-1 conformation and has a j3-D- anomeric linkage. 

Methyl thiolincosaminide (65), a carbohydrate component of the antibiotic lincomycin has been identified by n.m.r. An unusually... 

Elucidation of the complete structure of the neomycins (2) was not achieved until 1962. The long and arduous path to the total structure was followed through the stepwise solution of the structures of its four carbohydrate components by Rinehart and his associates at the University of Illinois. The detailed presentation of the work leading to the complete structure is beyond the scope of this review, which will deal only with the nature of the individual moieties. The relationship of neomycin to paromomycin and other similar antibiotics has also been clarified by these workers and will be discussed later. 

A related family of 3-amino-2,3,6-trideoxyhexoses, L-daunosamine (386), the carbohydrate component of anticancer anthracycline antibiotics, L-vancosamine (387), the carbohydrate component of the antibiotics vancomycin and sporaviridin, and D-ritosamine (388), the enantiomer of the carbohydrate component of the antibiotic ristomycin, has been prepared from ethyl L-lactate [119]. 

A 2 4- 2 strategy was employed in the chemical synthesis of a-D-Fuc-(l- -4)-a-D-Fuc-(l->4)-a-D-Qui-(l- 4)-D-Qui (Qui = 6-deoxy-D-glucose) which is a carbohydrate component of asterosaponin A from a starfish, and the multi-deoxy tetrasaccharide 17 has been found as a component of the aristostatin antibiotics. ... 

Hamada and Shioiri have employed their modification of the Schdllkopf reaction i.e., DPPA-mediated carboxylic acid activation) in the synthesis of L-daunosamine, the carbohydrate component of several important anthracycline antibiotics, including adriamycin and... 

Sttaricskai F, Pelyvas-Ferencrik I. Chemistry of carbohydrate components. Nagarajan R. ed. Glycopeptide Antibiotics. New York Marcel Dekker, 1993 105-193. 

Foster, A. B., T. D. Inch, J. Lehmann, M. Stacey, and J.M. Webber Carbohydrate components of antibiotics. Part III. Synthesis of 3,6-dideoxy-3-dimethyl-amino-j5-D-glucose hydrochloride monohydrate the absolute configuration of mycaminose. J. Chem. Soc. 1962, 2116. 

Oligosaccharides also occur widely as components (via glycosidic bonds) of antibiotics derived from various sources. Figure 7.20 shows the structures of a few representative carbohydrate-containing antibiotics. Some of these antibiotics also show antitumor activity. One of the most important of this type is bleomycin A2, which is used clinically against certain tumors. 

In addition to terpenes (as described above), carbohydrates have also been used as substrates in domino metathesis reactions, the aim being to synthesize enan-tiopure polyhydroxylated carbocyclic rings. These structures are components of several biologically active compounds such as aminoglycoside antibiotics [254], inositol phosphates [255], and carbanucleosides [256]. An efficient entry to this skeleton was developed by Madsen s group using a domino RCM/CM of the carbohy-... 

Treatment cf these disease states may be based on vaccination or drugs. In some cases, e.g. swine dysentery, no vaccines are available, so antibiotic treatment is essential. Antibiotic administration may be prophylactic or therapeutic with pigs, in particular, agents to control dysentery are routinely added to feedstuff or drinking water. The route of administration may also be highly important. For instance, in ruminants the preferred mode is injection, e.g. parenterally. The oral route, which introduces antibiotics directly into the rumen, may upset the delicate balance of rumen bacteria which are necessary to ferment carbohydrates to fatty acids — an essential component of the energy supply of ruminants. 

H. Grisebach, Biosynthesis of sugar components of antibiotic substances, Adv. Carbohydr. Chem. Biochem. 35 81 (1978). 

D-Apiose can be isolated from parsley and is a component of the cell wall polysaccharide of various marine plants. Among its novel structural features is the presence of only a single chirality center. L-Vancosamine is but one portion of vancomycin, a powerful antibiotic that has emerged as one of only a few antibiotics that are effective against drug-resistant bacteria. L-Vancosamine is not only a branched-chain carbohydrate, it is a deoxy sugar and an amino sugar as well. 

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