FORTIMICINS A AND B, NEW AMINOGLYCOSIDE ANTIBIOTICS

II. ISOLATION, PHYSICO-CHEMICAL AND CHROMATOGRAPHIC PROPERTIES

Abstract

The aminoglycoside antibiotics fortimicins A and B produced by a naturally occurring strain Micromonospora sp. MK-70 were isolated from its fermentation beer. Fortimicins A and B were isolated as water-soluble, basic, white amorphous powders having molecular formula C₁₇H₃₅N₅O₆ and C₁₅H₃₂N₄O₅, respectively. Acid hydrolysis of fortimicin A indicated
that it has one mole of glycine in its molecule while fortimicin B has not. Paper chromatography, silica-gel and carbon thin-layer chromatography revealed that fortimicins A and B are novel aminoglycoside antibiotics.