抄録
The presence of leucine, threonine, and α, γ-diaminobutyric acid in the HCI-hydrolysate of colistin was confirmed by paper chromatography. These amino acids were further isolated pure by fractional precipitation with ethanol and by the use of ion exchangers, and confirmed by the following specific rotations: Leucine, [α]15D:+10.0°(c=0.3, H2O): threonine, [α]D11:-28.7°(c=1.9, H2O): α, γ-diaminobutyric acid, [α]D11:+8.9°(c=2.2, H2O). A fatty acid, possessing a molecular formula of C9H18O2, was isolated as a p-bromophenacyl ester, m.p. 59°, [α]D15: -24.0 (c=1.0, MeOH) from the oily portion that separated out during hydrolysis of colistin with hydrochloric acid. It was clarified that the properties of this ester were identical with the p-bromophenacyl ester of D-6-methyloctanoic acid.
