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Nephrotoxicity was more marked in rats receiving isepamicin at midlight than at middark. And, the once-daily administration at middark induced a lesser degree of nephrotoxicity than the twice-daily injection, which indicates that the once-daily treatment therapy may have potential value in the clinical use of aminoglycosides.

(2-O-hexadecyl)PI], were tested as substrates or inhibitors of glycosylphosphatidylinositol (GPI) bio-synthetic pathways using cell-free systems of the proto-zoan parasite Trypanosoma brucei (the causative agent of human African sleeping sickness) and human HeLa cells. Neither these compounds nor their N-acetyl derivatives are substrates or inhibitors of GPI bio-synthetic enzymes in the HeLa cell-free system but are potent inhibitors of GPI biosynthesis in the T.brucei cell-free system. GlcN-(2-O-hexadecyl)PI was shown to inhibit the first α-mannosyltransferase of the trypano-somal GPI pathway. The N-acetylated derivative GlcNAc-(2-O-octyl)PI is a substrate for the trypano-somal GlcNAc-PI deN -acetylase and this compound, like GlcN-(2-O-octyl)PI, is processed predominantly to Man 2 GlcN-(2-O-octyl)PI by the T.brucei cell-free system. Both GlcN-(2-O-octyl)PI and GlcNAc-(2-O-octyl)PI also inhibit inositol acylation of Man 1-3 GlcN-PI and, consequently, the addition of the ethanolamine phosphate bridge in the T.brucei cell-free system. The data establish these substrate analogues as the first generation of in vitro parasite GPI pathway-specific inhibitors.

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This report describes a simple synthesis of 2-azido-3,4,6-tri-O-benzyl-2-deoxy-d-glucopyranose. Glycosylation using this as well as 2-azido-3,4,6-tri-O-benzyl-2-deoxy-d-galactopyranose and -mannopyranose was achieved with the aid of a reagent system consisting of p-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, and triethylamine, and its modifications. O-(2-Acetamido-2-deoxy-β-d-glucopyranosyl)-(1→4)-O-α-d-mannopyranosyl-(1→4)-α-d-mannopyranose, the repeating unit of the main chain of the O-specific cell wall polysaccharide of E. coli 058 was synthesized.