This invention relates to 6-ethylpenicillanic acid and 6-ethylpenicillanic acid sulfoxide (I) and their pharmaceutically acceptable salts and esters which are useful as antibiotics: ##STR2## This invention also relates to processes for preparing I; pharmaceutical compositions comprising I and methods of treatment comprising administering I when an antibiotic effect is indicated.
There is a continuing need for new antibiotics. For unfortunately there is no static effectiveness of any given antibiotic because continued wide scale usage selectively gives rise to resistant strains of pathogens. In addition, the known antibiotics suffer from the disadvantage of being effective only against certain types of microorganisms. Accordingly the search for new antibiotics continues.
Thus, it is an object of the present invention to provide a novel antibiotic and the pharmaceutically acceptable salts and esters thereof which are useful in animal and human therapy and in inanimate systems. These antibiotics are active against a broad range of pathogens which representatively include both gram positive bacteria such as S. aureus, Strep. pyogenes and B. subtilis, and gram negative bacteria such as E. coli, Proteus morganii, Serratia and Klebsiella. Further objects of this invention are to provide chemical processes for the preparation of such antibiotics and their non-toxic pharmaceutically acceptable salts; pharmaceutical compositions comprising such antibiotics; and to provide methods of treatment comprising administering such antibiotics and compositions when an antibiotic effect is indicated.