Aim To develop a novel selective protection strategy for the synthesis of ribostamycin cyclic carbamate derivatives. Methods Ribostamycin protected by carbobenzoxy group was treated with Nail, to give different protec...Aim To develop a novel selective protection strategy for the synthesis of ribostamycin cyclic carbamate derivatives. Methods Ribostamycin protected by carbobenzoxy group was treated with Nail, to give different protected intermediates under respective controllable cyclization reaction conditions. New ribostamycin derivative was obtained after the cleavage of carbobenzoxy groups. Result The novel selective protection of ribostamycin was achieved by the synthesis of protected intermediates. New ribostamycin derivative was obtained, but showed no expected antibacterial activity. Conclusion Several ribostamycin cyclic carbamate derivatives were obtained by novel selective protection strategy, which shows the practicability and convenience of the protection strategy. But these new ribostamycin derivatives containing cyclic carbamates structure may not be an ideal leading compound for antibiotic activity.展开更多
In order to develop new antibiotics effective against resistant bacteria,a series of novel 15-membered macrolide derivatives were designed and synthesized by the modification of hydroxyl groups at C-11,C-12 and C-4＂ ...In order to develop new antibiotics effective against resistant bacteria,a series of novel 15-membered macrolide derivatives were designed and synthesized by the modification of hydroxyl groups at C-11,C-12 and C-4＂ positions.Their structures were confirmed by MS,IR,^1H NMR or ^13C NMR.展开更多
According to LN?,theoretical&true elongation of tensile,and by adopting the increasing function of formulas with the derivation and analogy methods,the elongation formula of 0<(1+ε)^1/ε<e&0<ε^1/ε&...According to LN?,theoretical&true elongation of tensile,and by adopting the increasing function of formulas with the derivation and analogy methods,the elongation formula of 0<(1+ε)^1/ε<e&0<ε^1/ε<1&four convergences are deduced too whenε>1 and 0<ε<1.The inequalities of LNε<εand LN(1+ε)<εand LN(1+ε)>LNεare deduced ifε>1 and 0<ε<1 in material dynamics.Finally the conclusions of LNε<εand LNε<LN(1+ε)<εare deduced together ifε>1 and 0<ε<1.展开更多
基金The National Basic Research Program(973Program,Grant No.2004CB518904).
文摘Aim To develop a novel selective protection strategy for the synthesis of ribostamycin cyclic carbamate derivatives. Methods Ribostamycin protected by carbobenzoxy group was treated with Nail, to give different protected intermediates under respective controllable cyclization reaction conditions. New ribostamycin derivative was obtained after the cleavage of carbobenzoxy groups. Result The novel selective protection of ribostamycin was achieved by the synthesis of protected intermediates. New ribostamycin derivative was obtained, but showed no expected antibacterial activity. Conclusion Several ribostamycin cyclic carbamate derivatives were obtained by novel selective protection strategy, which shows the practicability and convenience of the protection strategy. But these new ribostamycin derivatives containing cyclic carbamates structure may not be an ideal leading compound for antibiotic activity.
基金supported by NNSFC(No.20372043),Shandong Science and Technology Promotion Project(No.2005GG3202098)Natural Science Foundation of Shandong Province(No.Y2006C31).
文摘In order to develop new antibiotics effective against resistant bacteria,a series of novel 15-membered macrolide derivatives were designed and synthesized by the modification of hydroxyl groups at C-11,C-12 and C-4＂ positions.Their structures were confirmed by MS,IR,^1H NMR or ^13C NMR.
基金KNRF(the Korea of National Research Foundation)under the Specified base program 96-0300-11-01-3.
文摘According to LN?,theoretical&true elongation of tensile,and by adopting the increasing function of formulas with the derivation and analogy methods,the elongation formula of 0<(1+ε)^1/ε<e&0<ε^1/ε<1&four convergences are deduced too whenε>1 and 0<ε<1.The inequalities of LNε<εand LN(1+ε)<εand LN(1+ε)>LNεare deduced ifε>1 and 0<ε<1 in material dynamics.Finally the conclusions of LNε<εand LNε<LN(1+ε)<εare deduced together ifε>1 and 0<ε<1.
