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 1 mol of glycine in its molecule, while fortimicin B doesn''t. Paper chromatography, silica-gel and carbon TLC revealed that fortimicins A and B are novel aminoglycoside antibiotics.