The 3＇-OH, 4＇-OH and 2＂-OH of kanamycin A were modified in search of new aminoglycosides to overcome resistant enzymes, ANTs and APHs. The key intermediate was a dibenzylidene-protected derivative of kanamycin A. T...The 3＇-OH, 4＇-OH and 2＂-OH of kanamycin A were modified in search of new aminoglycosides to overcome resistant enzymes, ANTs and APHs. The key intermediate was a dibenzylidene-protected derivative of kanamycin A. The aimed sites were masked by benzyl, methyl and allyl groups. Multi-step reactions gave the desired aminoglycoside derivatives but showed less antibiotic activity than kanamycin A.展开更多
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 the present study,we aimed to investigate the effect of puromycin aminonucleoside(PAN)on the expression and distribution of transient receptor potential canonical 6(TRPC6)of murine podocytes and further study the p...In the present study,we aimed to investigate the effect of puromycin aminonucleoside(PAN)on the expression and distribution of transient receptor potential canonical 6(TRPC6)of murine podocytes and further study the protective mechanism of fluvastatin on podocyte injury by TRPC6 in vitro.Podocytes were treated by PAN at different doses and at different time points.The expressions of TRPC6 at mRNA and protein levels were assessed.An immunofluorescent assay was used to observe the distribution of TRPC6.Cultured podocytes were then divided into four groups.The expressions of TRPC6 at mRNA and protein levels were measured.The intracellular calcium concentration of podocytes was measured with a laser-scanning confocal microscope.The paracellular permeability to BSA was evaluated using Millicell-PCF Inserts.The expressions of TRPC6 at mRNA and protein levels were increased in a dose and time-dependent manner after exposure to PAN.Immunofluorescence showed that the expression intensity of TRPC6 was significantly increased,and the distribution of TRPC6 was changed after PAN was applied to podocytes.With fluvastatin intervention,PAN-induced up-regulation of TRPC6 was significantly reversed.The ratio of the peak value of intracellular calcium to the basic calcium value in the PAN group was significantly higher after TRPC6 was activated by OAG,while it is obviously reversed under the action of fluvastatin.The podocyte permeability was significantly increased after 48 h of PAN treatment,while the above situation was effectively improved after fluvastatin intervention.The changes of distribution and expression of TRPC6 were related to podocyte injury induced by PAN.Fluvastatin could exert its protective effects on podocytes by down-regulating TRPC6.展开更多
基金National Basic Research Program(973 Program,Grant No.2004CB518904).
文摘The 3＇-OH, 4＇-OH and 2＂-OH of kanamycin A were modified in search of new aminoglycosides to overcome resistant enzymes, ANTs and APHs. The key intermediate was a dibenzylidene-protected derivative of kanamycin A. The aimed sites were masked by benzyl, methyl and allyl groups. Multi-step reactions gave the desired aminoglycoside derivatives but showed less antibiotic activity than kanamycin A.
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National Natural Science Foundation of China(Grant No.81400333)。
文摘In the present study,we aimed to investigate the effect of puromycin aminonucleoside(PAN)on the expression and distribution of transient receptor potential canonical 6(TRPC6)of murine podocytes and further study the protective mechanism of fluvastatin on podocyte injury by TRPC6 in vitro.Podocytes were treated by PAN at different doses and at different time points.The expressions of TRPC6 at mRNA and protein levels were assessed.An immunofluorescent assay was used to observe the distribution of TRPC6.Cultured podocytes were then divided into four groups.The expressions of TRPC6 at mRNA and protein levels were measured.The intracellular calcium concentration of podocytes was measured with a laser-scanning confocal microscope.The paracellular permeability to BSA was evaluated using Millicell-PCF Inserts.The expressions of TRPC6 at mRNA and protein levels were increased in a dose and time-dependent manner after exposure to PAN.Immunofluorescence showed that the expression intensity of TRPC6 was significantly increased,and the distribution of TRPC6 was changed after PAN was applied to podocytes.With fluvastatin intervention,PAN-induced up-regulation of TRPC6 was significantly reversed.The ratio of the peak value of intracellular calcium to the basic calcium value in the PAN group was significantly higher after TRPC6 was activated by OAG,while it is obviously reversed under the action of fluvastatin.The podocyte permeability was significantly increased after 48 h of PAN treatment,while the above situation was effectively improved after fluvastatin intervention.The changes of distribution and expression of TRPC6 were related to podocyte injury induced by PAN.Fluvastatin could exert its protective effects on podocytes by down-regulating TRPC6.
