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  • K Imae, H Kamachi, +7 authors T Naito
  • 1991
Syntheses of melanostatin and feldamycin have been completed from L-serine and L-threonine, respectively, and the configuration of unknown asymmetric carbons determined. Feldamycin analogs have also been prepared and the L-tryptophyl analog was the most potent in the depigmentation of Streptomyces bikiniensis and B16 melanoma cells.
7-[(Z)-2-(2-Aminothiazol-4-yl)-2-methoxy-(or hydroxy)-iminoacetamido]-3- [propen-1-yl]-cephalosporins having a variety of heterocyclic catechol in 3-position of the propenyl group were synthesized. Among them, 6,7-dihydroxyisoquinoline derivatives, 2a and 2b, showed very high and prolonged blood levels after intramuscular administration to mice and higher(More)
Cephalosporins having a catechol through a variety of linkages to the C3 position and a different C7 side chain were prepared. Among them, 3-(catechol-4- ylcarbonyloxy)methylcephalosporin (14) and 3-[(E)-3-(catechol-4-ylcarbonyloxy)-1-propen-1-yl]cephalospo rin (10) showed excellent activity against Gram-negative activity including ceftazidime-resistant(More)
Two groups of cephalosporins substituted with a variety of heterocyclic catechols in the C3 side chain were synthesized. One is a group of 3-(heterocyclic catechol-substituted methyl)cephalosporins and another is 3-[(E)-3-heterocyclic catechol-substituted 1-propen-1-yl]cephalosporins. Cephalosporins in the latter group showed higher in vivo efficacies than(More)
Collaborative editing is one of the most significant topics in distributed systems because it includes a problem of consistency maintenance on shared data in distributed systems. There are so many papers which have proposed various approaches to this problem so far. Most of the solutions that have already proposed are for document editing, but there are a(More)
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