A compound of the formula ##STR1## wherein R.sup.1 is amino or substituted amino, R.sup.2 is carboxy or protected carboxy, R.sup.3 is lower alkyl and X is --S-- or ##STR2## or a pharmaceutically acceptable salt thereof is effective against various microorganisms.
该化合物的公式为##STR1##,其中R.sup.1是
氨基或取代
氨基,R.sup.2是羧基或保护羧基,R.sup.3是低级烷基,X是--S--或##STR2##,或其药物可接受的盐对各种微
生物有效。