Abstract: A new antibacterially active agent has been isolated from Streptomyces clavuligerus. This new compound which is designated clavulanic acid has the formula (I): ##STR1## In addition to being a broad spectrum antibiotic of medium potency, clavulanic acid and its salts and esters have the ability to enhance the effectiveness of .beta.-lactam antibiotics against many .beta.-lactamase producing bacteria.

Abstract: A new antibacterially active agent has been isolated from Streptomyces clavuligerus. This new compound which is designated clavulanic acid has the formula (I): ##STR1## In addition to being a broad spectrum antibiotic of medium potency, clavulanic acid and its salts and esters have the ability to enhance the effectiveness of .beta.-lactam antibiotics against many .beta.-lactamase producing bacteria.

Abstract: 7.alpha.-Hydroxyamino-7.beta.-[2-substituted-2-(acylamino)acetamido]-cephal osporin antibiotics, pharmaceutically-acceptable salts and in vivo hydrolyzable esters thereof, a method of treating susceptible infections therewith, and intermediates therefor.

Abstract: 7.alpha.-Hydroxyamino-7.beta.-[2-substituted-2-(acylamino)acetamido]cephalo sporin antibiotics, pharmaceutically-acceptable salts and in vivo hydrolyzable esters thereof, a method of treating susceptible infections therewith, and intermediates therefor.

Abstract: The compounds of the formula (II): ##STR1## and salts and esters thereof wherein R is an inert organic group of up to 18 carbon atoms and are able to inhibit the action of various bacterial .beta.-lactamases. Thus when a compound of the formula (II) or its salt or ester is used together with a penicillin or cephalosporin, the effectiveness of that penicillin or cephalosporin can be considerably enhanced. These novel synergysts can be prepared by etherification of an ester of clavulanic acid followed if desired by deesterification. The novel synergysts also possess antibacterial activity.

Abstract: The present invention provides the compounds of the formula (II): ##STR1## and salts and esters thereof wherein R.sub.1 is a hydrogen atom or an alkyl group of 1-4 carbon atoms and R.sub.2 is a hydrogen atom or an alkyl group of 1-4 carbon atoms or is joined to R.sub.1 to form part of a 5-, 6- or 7 membered carbocyclic ring. These compounds are .beta.-lactamase inhibitors able to enhance the effectiveness of pencillins and cephalosporins. Their preparation and compositions containing them are described.

Abstract: A new antibacterially active agent has been isolated from Streptomyces clavuligerus. This new compound which is designated clavulanic acid has the formula (I): ##STR1## In addition to being a broad spectrum antibiotic of medium potency, clavulanic acid and its salts and esters have the ability to enhance the effectiveness of .beta. lactam antibiotics against many .beta.-lactamase producing bacteria.

Abstract: A new antibacterially active agent has been isolated from Streptomyces clvuligerus. This new compound which is designated clavulanic acid has the formula (I): ##STR1## In addition to being a broad spectrum antibiotic of medium potency, clavulanic acid and its salts and esters have the ability to enhance the effectiveness of .beta.-lactam antibiotics against many .beta.-lactamase producing bacteria.

Abstract: The compounds of the formula (II): ##STR1## and salts and esters thereof wherein R is an inert ogranic group of up to 18 carbon atoms and are able to inhibit the action of various bacterial .beta.-lactamases. Thus when a compound of the formula (II) or its salt or ester is used together with a penicillin or cephalosporin, the effectiveness of that penicillin or cephalosporin can be considerably enhanced. These novel synergysts can be prepared by etherification of an ester of clavulanic acid followed if desired by deesterification. The novel synergysts also possess antibacterial activity.

Abstract: A new antibacterially active agent has been isolated from Streptomyces clavuligerus. This new compound which is designated clavulonic acid has the formula (I): ##STR1## In addition to being a broad spectrum antibiotic of medium potancy, clavulanic acid and its salts and esters have the ability to enhance the effectiveness of .beta. lactam antibiotics against many .beta.-lactamase producing bacteria.

Abstract: A new antibacterially active agent has been isolated from Streptomyces clavuligerus. This new compound which is designated clavulanic acid has the formula (I): ##STR1## In addition to being a broad spectrum antibiotic of medium potency, clavulanic acid and its salts and esters have the ability to enhance the effectiveness of .beta.-lactam antibiotics against many .beta.-lactamase producing bacteria.

Abstract: A new antibacterially active agent has been isolated from Streptomyces clavuligerus. This new compound which is designated clavulanic acid has the formula (I): ##STR1## In addition to being a broad spectrum antibiotic of medium potency, clavulanic acid and its salts and esters have the ability to enhance the effectiveness of .beta. lactam antibotics against many .beta.-lactamase producing bacteria.

Abstract: A new antibacterially active agent has been isolated from Streptomyces clavuligerus. This new compound which is designated clavulanic acid has the formula (I): ##STR1## In addition to being a broad spectrum antibiotic of medium potency, clavulanic acid and its salts and esters have the ability to enhance the effectiveness of .beta.-lactam antibiotics against many .beta.-lactamase producing bacteria.

Abstract: The compounds of the formula (II): ##STR1## and salts and esters thereof wherein R.sub.1 is an inert organic group of up to 14 carbon atoms and R.sub.2 is an inert organic group of up to 16 carbon atoms, the group NR.sub.1 R.sub.2 containing up to 22 carbon atoms, are antibacterial agents able to enhance the effectiveness of penicillins and cephalosporins against certain .beta.-lactamase producing bacteria.

Abstract: The compounds of the formula: ##STR1## and salts and esters thereof are useful agents for the treatment of bacterial infections either alone or in combination with a penicillin or cephalosporin derivative. The preceding compounds may be prepared by the hydrogenation of a compound of the formula: ##STR2## wherein R is a hydrogen atom or an acyl group or a salt or ester thereof.

Abstract: A new antibacterially active agent has been isolated from Streptomyces clavuligerus. This new compound which is designated clavulanic acid has the formula (I): ##STR1## In addition to being a broad spectrum antibiotic of medium potency, clavulanic acid and its salts and esters have the ability to enhance the effectiveness of .beta.-lactam antibiotics against many .beta.-lactamase producing bacteria.

Abstract: This invention provides the compounds of the formula (II): ##STR1## and salts and esters thereof, wherein R.sub.1 is H and R.sub.3 is H or an aryl, aralkyl, lower alkyl or substituted lower alkyl group or R.sub.1 and R.sub.3 are joined so that the CHR.sub.1.NH.CO.R.sub.3 moiety forms a group of the sub-formula (a): ##STR2## wherein R.sub.4 is a hydrogen atom or a NH.CO.R.sub.5 group wherein R.sub.5 is a lower alkyl, lower alkoxy lower alkyl, aryl, aralkyl, aryloxyalkyl, lower alkoxy or aryloxy group.The compounds have .beta.-lactamase inhibitory and anti-bacterial properties.The invention also provides a process for their preparation, and pharmaceutical compositions containing them.

Abstract: The compounds of the formula (II): ##STR1## and salts and esters theereof wherein R.sub.1 is an inert organic group of up to 14 carbon atoms and R.sub.2 is an inert organic group of up to 16 carbon atoms, the group NR.sub.1 R.sub.2 containing up to 22 carbon atoms, are antibacterial agents able to enhance the effectiveness of penicillins and cephalosporins against certain .beta.-lactamase producing bacteria.

Abstract: Compounds of the formula (I): ##STR1## and salts and esters thereof, wherein R.sub.1 is a hydrogen atom or a lower alkyl, aryl or aralkyl group, R.sub.2 and R.sub.3 are independently hydrogen, aryl, aralkyl, lower alkyl or substituted lower alkyl, or R.sub.3 is joined to R.sub.1 to form a 4-, 5-, or 6- membered ring or is joined to R.sub.2 to form a 5- or 6- membered ring with the proviso that when R.sub.2 is hydrogen, R.sub.1 is not hydrogen and R.sub.1 and R.sub.3 are not joined to form a group of the sub-formula (a) wherein R.sub.4 is a hydrogen atom or a NH.CO.R.sub.5 group wherein R.sub.5 is a lower alkyl, lower alkoxy lower alkyl, aryl, aralkyl, aryloxyalkyl; lower alkoxy or aryloxy group have .beta.-lactamase inhibitory and anti-bacterial properties.

Abstract: The compounds of the formula: ##STR1## and salts and esters thereof are useful agents for the treatment of bacterial infections either alone or in combination with a penicillin or cephalosporin derivative. The preceding compounds may be prepared by the hydrogenation of a compound of the formula: ##STR2## wherein R is a hydrogen atom or an acyl group or a salt or ester thereof.