Neomycin Aminoglycoside

Aminoglycosides. Antibiotics ia the amiaoglycoside group characteristically contain amino sugars and deoxystreptamiae or streptamiae. This family of antibiotics has frequentiy been referred to as aminocyclitol amiaoglycosides. Representative members are streptomycia, neomycin, kanamycia, gentamicin, tobramycia, and amikacin. These antibiotics all inhibit proteia biosynthesis. 

The aminoglycosides include amikacin (Amikin), gentamicin (Garamycin), kanamycin (Kantrex), neomycin (Mycifradin), netilmicin (Netromycin), streptomycin, and tobramycin (Nebcin). 

Because the oral aminoglycosides are poorly absorbed, they are useful to suppressing gastrointestinal bacteria The oral aminoglycosides kanamycin (Kantrex) and neomycin (Mycifradin) are used preoperatively to reduce the number of bacteria normally present in the intestine (bowel prep). A reduction in intestinal bacteria is thought to lessen the possibility of abdominal infection that may occur after surgery on the bowel. 

Arya DP (2005) Aminoglycoside-Nucleic Acid Interactions The Case for Neomycin. 253 ... 

Development of resistance to rifaximin is primarily due to a chromosomal one-step alteration in the drug target, DNA-dependent RNA polymerase. This differs from the plasmid-mediated resistance commonly acquired by bacteria to aminoglycoside antibiotics such as neomycin... 

The answer is a. (Hardman, pp 1105-1108.) The activity of streptomycin is bactericidal for the tubercle bacillus organism. Other aminoglycosides (e.g., gentamicin, tobramycin, neomycin, amikacin, and kanamycin) have activity against this organism but are seldom used clinically because of toxicity or development of resistance. 

Commercial neomycin is a complex mixture of aminoglycoside antibiotics originally isolated from a culture of Stn.tptomyc.zi, ( n.adiaz by Waksman and his co-workers in 1949. The principle components of the mixture are neomycin B(I) and neomycin C(II) together with a small quantity of neaminel, a degradation product of neomycin formerly known as neomycin A. Table 1 shows the content variability of neomycin B and C and neamine in commercial samples of neomycin as reported in the literature. Neomycins LP-A, LP-B and LP-C which chemically are the mono N-acetyl derivatives of neomycins A, B and C may also be present in small amounts. Several other minor components have recently been identified as paromamine, paromomycin I and paromomycin II. (Also known as neomycins D, E and F respectively). 

During a study of the physicochemical properties of some aminoglycoside antibiotics Kuzyaeval- - determined the static and dynamic exchange capacities of neomycin on the cation exchange resin KB-4P-2(a phenoxyacetic ac. d-f ormaldehyde resin) using the resin in the Na form. 

Neomycin is a readily ionisable molecule and should thus be separable from other antibiotics by application of an electric field (zone electrophoresis). Various workers have successfully applied this technique to neomycin and Table 10 summarises the conditions reported in the literature. A number of authors described the qualitative separation of neomycin from other chemical-types of antibiotics using paper-electro-phoresis181,185,187 while Ochabl89 described systems specifically designed to separate compounds within the aminoglycoside group of antibiotics. 

Neomycin has been separated from mixtures of other aminoglycoside antibiotics containing the 2-deoxystreptamine moiety as both the pertrimethylsilyl derivative and the N-trifluoro-acetyl pertrimethylsilyl derivative using a column of 0.75% 0V-1 on Gas Chrom q240. The procedure may be used to estimate the number of sugar moieties bound in the antibiotic as a close relationship exists between the number of rings and the retention time. 

An enzymic assay involving the reaction of neomycin with aminoglycoside 4 adenyltransferase has been described l. a linear response for neomycin was observed over the range 2.5 to 20yg/ml serum. 

Likewise, the antoconvulsant phenytoin sodium and neomycin—an aminoglycoside antibiotic also decrease the cholesterol levels, and... 

Similar well-shaped responses have been obtained at a gold electrode using the aminoglycoside neomycin (neomycin sulfate), which is a positively charged promoter favouring the electrostatic interaction with negatively charged proteins.36... 

Fig. 9 Schematic representation of the target conformationally locked aminoglycosides (2-4) and the deoxy derivatives (5, 6). The numbering employed for the different sugar units is indicated for neomycin-B (compound 1)...

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