Compounds of the formula:
and the pharmaceutically acceptable salts thereof wherein
wherein each R is hydrogen or alkyl of 1 to 6 carbon atoms are disclosed. The compounds are useful as antibiotics.
式化合物
及其药学上可接受的盐类,其中
其中每个 R 均为氢或 1 至 6 个碳原子的烷基。这些化合物可用作抗生素。