反应详情

Istamycin B is very similar to istamycin A in its properties, and istamycin B is also a basic compound. Istamycin B isolated as a carbonate thereof is in the form of a colorless powder which has no definite melting point, decomposes at 112°-124° C. and gives a specific optical rotation [α]D25 =+165° (c 0.4, water) and of which the elemental analysis is coincident with the theoretical values of the molecular formula C17H35N5O5.1/2H2CO3 (C 49.99%, H 8.63%, N 16.65%, O 24.73%). This molecular formula has been confirmed by high-resolution mass-spectrometry (Found: m/e 389.2625; Calcd. for C17H35N5O5 : m/e 389.2635). The infra-red absorption spectrum of istamycin B hemi-carbonate pelleted in potassium bromide is shown in FIG. 2 of the attached drawings. The ultraviolet absorption spectrum of the istamycin B hemi-carbonate in water shows only end absorption. In the proton (1H) nuclear magnetic resonance absorption spectrum (external standard: TMS, pD 5.4) of istamycin B hemi-carbonate in deutero-water, there are shown characteristic signals at δ3.26 (s, N-CH3), 3.59 (s, N-CH3), 3.95 (s, O-CH3), 4.57 (s, CH2) and 5.96 (d, J=3.5 Hz, CH). Like istamycin A, istamycin B is soluble in water and methanol but sparingly soluble or insoluble in ethanol and other common organic solvents, and it is positive to the ninhydrin reaction and to the Rydon-Smith reaction. As stated hereinbefore, istamycin B is separable from istamycin A by thin layer chromatography on cellulose.