Herperal,Farmitalia,Italy,1978
A spore suspension obtained upon washing a culture of Streptomyces
distallicus is added to 3,000 ml of a sterile medium consisting of the
following:Dextrose 2%
Corn steep liquor extract 2%
CaCO3 1%
(NH4)2SO4 0.3%
NaCl 0.3%Fermentation is continued at 28°C for 40 hours at a stirring rate of 150 to 250
rpm and a rate of air flow of 1 to 2 l/min/l of culture medium.
300 ml of a suspension of the vegetative mycelium of this culture are used for
inoculating 6,000 ml of a similar sterile culture medium. At this production
stage, the culture is kept fermenting for 85 to 100 hours (pH 7.6 at 28°C) at
a stirring rate of 350 to 450 rpm and a rate of air flow of 1 to 1.5 l/min/l of
culture medium.
To 17 l of a culture obtained by submerged fermentation as mentioned above,
siliceous earth is added and the batch is filtered. The mixture of mycelium and
the siliceous earth are agitated for 1 hour with 2.5 l of butanol. This treatment
is repeated twice. The butanolic extracts are combined, washed with water,
evaporated to dryness (about 10 g) and boiled with acetone (80 ml). The 5 g of distamycin is extracted six times with ethanol. The ethanolic extracts
are combined, concentrated and filtered through a column containing 70 g of
alumina. Elution is carried out with the same solvent. The effluent (central
fractions) is collected and evaporated to dryness to yield 0.43 g of pure
distamycin A: decomposition point, 183°C to 185°C. The product can be
further purified by crystallization from aqueous n-butanol.
