Abstract: 3-Substituted-7-substituted alkanamido-3-cephem-4-carboxylic acid compounds and pharmaceutically acceptable salts thereof which have antimicrobial activities, processes for the preparation thereof, pharmaceutical compositions comprising the same, and methods of using the same therapeutically in the treatment of infections.

Abstract: A process for preparing a 7-substituted-3-cephem-4-carboxylic acid of the formula: ##STR1## or a pharmaceutically acceptable salt thereof, which comprises subjecting a corresponding 7-substituted-3-organic sulfonyloxy-3-cephem-4-carboxylic acid ester of the formula ##STR2## wherein R is a residue of an organic sulfonic acid, X is esterified carboxy which is an alkoxylcarbonyl, haloalkoxycarbonyl, substituted or unsubstituted aralkoxycarbonyl, benzhydryloxycarbonyl or trityloxycarbonyl, or a pharmaceutically acceptable salt thereof,to hydrogenolysis using a combination of a metal and formic acid as a reducing reagent.

Abstract: Cephalosporin compounds of the formula (I): ##STR1## wherein R.sup.1 is a group of the formula: ##STR2## in which X is sulfur, oxygen or substituted or unsubstituted imino,M is sulfur or oxygen,R.sup.2 is hydrogen, or a saturated or unsaturated aliphatic hydrocarbon residue,R.sup.3 is hydrogen or lower alkyl,R.sup.4 is hydrogen, halogen, lower alkyl, acyloxymethyl or heterocyclic-thiomethyl which may be substituted with lower alkyl, andR.sup.5 is carboxy or its derivative, and nontoxic, pharmaceutically salt thereof.

Abstract: A compound of the formula: ##STR1## wherein R.sup.1 is lower alkyl,R.sup.2 is carboxy or a protected carboxy group,R.sup.4 is hydrogen or lower alkyl andY is a residue of an acid, or a salt.

Abstract: R.sup.2 is an aliphatic hydrocarbon residue which may be substituted with hydroxy, protected hydroxy or lower alkylthio,R.sup.3 is a heterocyclic group substituted with amino(lower)alkyl, protected amino(lower)alkyl or hydroxy(lower)alkyl, andR.sup.4 is carboxy or functionally modified carboxy, "syn" or "anti" isomer.

Abstract: New antimicrobial azetidinone derivatives and their salt of the formula: ##STR1## wherein R.sub.1 is amino or acylamino, and A is selected from a variety of groups.

Abstract: The present invention relates to new syn-isomer of 3,7-disubstituted-3-cephem-4-carboxylic acid compounds and pharmaceutically acceptable salts thereof. More particularly, it relates to new syn-isomer of 3,7-disubstituted-3-cephem-4-carboxylic acid compounds and pharmaceutically acceptable salts thereof which have antibacterial activities and to processes for the preparation thereof, to pharmaceutical composition comprising the same, and to a method of using the same therapeutically in the treatment of infectious diseases in human beings and animals.

Abstract: A compound of the formula: ##STR1## wherein R.sup.1 is (C.sub.1 to C.sub.6) alkyl,R.sup.2 is a carboxy or a protected carboxy group,R.sup.3 is amino or a protected amino group andA is hydroxyimino (C.sub.1 to C.sub.6) alkylene or (C.sub.1 to C.sub.6)-alkoxyimino (C.sub.1 to C.sub.6)alkylene,And pharmaceutically acceptable salt thereof.

Abstract: The new 7-(.alpha.,.alpha.-disubstituted-acetamido)-3-substituted-3-cephem-4-carbo xylic acid of the present invention is represented by the following formula: ##STR1## wherein R.sup.1 is hydrogen, halogen, hydroxy, nitro, lower alkoxy or acylamino, R.sup.2 is hydrogen or acyl andR.sup.3 is lower alkanoyloxy, carbamoyloxy which may have lower alkyl, aryl or protective group for amino, or a heterocyclicthio which may have lower alkyl, aryl or protective group for amino, or a hetero- which may have lower alkyl.

Abstract: The present invention relates to new cephalosporanic acids and their derivatives and preparation thereof. More particularly, it relates to 7-dihaloalkanoylamido-3-heterocyclic-thiomethyl-3-cephem-4-carboxylic acids, their derivatives and their nontoxic pharmaceutically acceptable salts, which possess an antibacterial activity, process for preparation of the same and compositions thereof.