The Experts below are selected from a list of 1122 Experts worldwide ranked by ideXlab platform
Eunsook Jang - One of the best experts on this subject based on the ideXlab platform.
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an efficient and selective 1 n monoethylation of Sisomicin process development of netilmicin
Organic Process Research & Development, 2002Co-Authors: Ghilsoo Nam, Sung Hoon Kim, Joonghyup Kim, Junghyu Shin, Eunsook JangAbstract:With a new reagent developed for the selective monoethylation at the 1-amino group of Sisomicin (1), a new process suitable for the mass production of netilmicin under conditions less sensitive to air and moisture has also been developed. Three of the amino groups, at the C-3, C-2‘, and C-6‘ positions of the four amino groups of Sisomicin, were selectively protected by using Zn(OAc)2 and acetic anhydride in methanol. Development efforts focused on optimising the conditions for ethylation to give an improved product (96% yield) according to the new and concise synthetic route.
Tomoko Kasahara - One of the best experts on this subject based on the ideXlab platform.
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crystal structure and specific binding mode of Sisomicin to the bacterial ribosomal decoding site
ACS Medicinal Chemistry Letters, 2012Co-Authors: Jiro Kondo, Mai Koganei, Tomoko KasaharaAbstract:Sisomicin with an unsaturated sugar ring I displays better antibacterial activity than other structurally related aminoglycosides, such as gentamicin, tobramycin, and amikacin. In the present study, we have confirmed by X-ray analyses that the binding mode of Sisomicin is basically similar but not identical to that of the related compounds having saturated ring I. A remarkable difference is found in the stacking interaction between ring I and G1491. While the typical saturated ring I with a chair conformation stacks on G1491 through CH/π interactions, the unsaturated ring I of Sisomicin with a partially planar conformation can share its π-electron density with G1491 and fits well within the A-site helix.
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Crystal Structure and Specific Binding Mode of Sisomicin to the Bacterial Ribosomal Decoding Site
2012Co-Authors: Jiro Kondo, Mai Koganei, Tomoko KasaharaAbstract:Sisomicin with an unsaturated sugar ring I displays better antibacterial activity than other structurally related aminoglycosides, such as gentamicin, tobramycin, and amikacin. In the present study, we have confirmed by X-ray analyses that the binding mode of Sisomicin is basically similar but not identical to that of the related compounds having saturated ring I. A remarkable difference is found in the stacking interaction between ring I and G1491. While the typical saturated ring I with a chair conformation stacks on G1491 through CH/π interactions, the unsaturated ring I of Sisomicin with a partially planar conformation can share its π-electron density with G1491 and fits well within the A-site helix
Ghilsoo Nam - One of the best experts on this subject based on the ideXlab platform.
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an efficient and selective 1 n monoethylation of Sisomicin process development of netilmicin
Organic Process Research & Development, 2002Co-Authors: Ghilsoo Nam, Sung Hoon Kim, Joonghyup Kim, Junghyu Shin, Eunsook JangAbstract:With a new reagent developed for the selective monoethylation at the 1-amino group of Sisomicin (1), a new process suitable for the mass production of netilmicin under conditions less sensitive to air and moisture has also been developed. Three of the amino groups, at the C-3, C-2‘, and C-6‘ positions of the four amino groups of Sisomicin, were selectively protected by using Zn(OAc)2 and acetic anhydride in methanol. Development efforts focused on optimising the conditions for ethylation to give an improved product (96% yield) according to the new and concise synthetic route.
Johan W. Mouton - One of the best experts on this subject based on the ideXlab platform.
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Sisomicin and netilmicin
2017Co-Authors: Johan W. MoutonAbstract:Both Sisomicin and netilmicin are aminoglycosides similar to gentamicin, but only netilmicin offers any advantage over gentamicin and has been used regularly.
Chul Soo Shin - One of the best experts on this subject based on the ideXlab platform.
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analysis of Sisomicin binding sites in micromonospora inyoensis cell wall
Fems Microbiology Letters, 1998Co-Authors: Dae Ho Kim, Jung Hae Suh, Sung Kwan Yum, Chul Soo ShinAbstract:Sisomicin binding sites are located in the cell wall. They are the carboxyl groups of peptidoglycans, which are major components of the cell wall. The carboxyl groups have negative charges which can bind the positively charged amino groups of Sisomicin. When the negative charges of the carboxyl groups of the peptidoglycans are changed to neutral or positive charges, Sisomicin does not bind to the cell wall. Magnesium ions bind to the cell wall in competition with Sisomicin, and have a weak affinity for the cell wall binding sites compared with Sisomicin. The binding molar ratio of Sisomicin to magnesium ions was approximately 1 to 10.
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effect of magnesium sulfate on product inhibition of Sisomicin production
Journal of Microbiology and Biotechnology, 1995Co-Authors: Chul Soo Shin, Sanghun HanAbstract:Addition of l00mM to a cell culture after 54 hours resulted in a 2.4-fold increase in the Sisomicin titre compared to a control to which no was added, and a considerable amount of intracellular Sisomicin was liberated outside the cells. The occurrence of product inhibition in fermentation was confirmed by a reduction in net Sisomicin production with increasing amounts of added Sisomicin without addition of . All added Sisomicin was bound to Sisomicin-free cells in the absence of , whereas approximately 40% of added Sisomicin was bound with the addition of l00mM . Under conditions of no enzmye synthesis, maintained by adding chloramphenicol to exclude product repression, Sisomicin was produced in the presence of 100 mM but little Sisomicin was produced in the absence of .
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characteristics of Sisomicin fermentation supplemented with mgso4 in stirred and air lift fermentors
Biotechnology Letters, 1994Co-Authors: Chul Soo Shin, Seong Yong KimAbstract:Sisomicin fermentations were carried out in stirred and air lift fermentors, and various concentrations of MgSO4 were supplemented to improve antibiotic yield. The highest antibiotic yield was obtained at 80 mM in an air lift fermentor due to effective liberation of intracellular Sisomicin by MgSO4. The presence of high concentrations of MgSO4, along with shear stress due to strong agitation in the stirred fermentor, resulted in low values of cell activity, rheological parameter(n) and cell viability in the stirred fermentor, compared with the air lift fermentor. The better physiological states of cells grown in the air lift fermentor resulted in improved antibiotic yields.