A compound of the formula: ##STR1## wherein R.sup.1 is a hydrogen atom or a methyl group, R.sup.2 is a hydrogen atom or a negative charge, X is a group of --N(R.sup.3)R.sup.4 (wherein R.sup.3 is a lower alkyl group, and R.sup.4 is a hydrogen atom or a lower alkyl group) or a group of --N.sup.+ (R.sup.5)(R.sup.6)R.sup.7 (wherein each of R.sup.5, R.sup.6 and R.sup.7 which may be the same or different, is a lower alkyl group), and n is an integer of from 2 to 4; or a pharmaceutically acceptable salt or ester thereof.
该化合物的
化学式为:##STR1## 其中R.sup.1为氢原子或甲基基团,R.sup.2为氢原子或负电荷,X为--N(R.sup.3)R.sup.4基团(其中R.sup.3为低碳基基团,R.sup.4为氢原子或低碳基基团)或--N.sup.+ (R.sup.5)(R.sup.6)R.sup.7基团(其中R.sup.5、R.sup.6和R.sup.7可以相同或不同,为低碳基基团),n为2到4的整数;或其药学上可接受的盐或酯。