Abstract: Erythromycin A derivatives represented by the general formula wherein R1 is a 2-alkenyl group having 3 to 15 carbon atoms, an arylmethyl group, or an arylmethyl group substituted by 1 to 3 of a halogen atom, an alkoxy group 1 to 4 carbon atoms, a nitro group or an alkoxycarbonyl group having 2 to 6 carbon atoms, R2 is a substituted silyl group and R3 is a hydrogen atom or R2, are disclosed. These compounds are useful as intermediates of the anti-bacterial agents.

Abstract: Erthromycin A derivatives represented by the general formula ##STR1## wherein R.sup.1 is a group of the formula R.sup.7 CH.sub.2 -- (wherein R.sup.7 is a hydrogen group or a lower alkyl group) or a group of the formula R.sup.8 O-- (wherein R.sup.8 is a lower alkyl group), R.sup.2 is R.sup.8, a cycloalkyl group, a phenyl group or an aralkyl group.), or R.sup.2 and R.sup.7 together form an alkylene group, R.sup.3 is a hydrogen atom, a lower alkyl group, a phenyl group or an aralkyl group, or R.sup.3 and R.sup.7 together form an alkylene group, or R.sup.2 and R.sup.3 together form an alkylene group, R.sup.4 is a lower alkyl group, R.sup.5 is a substituted silyl group, and R.sup.6 is a hydrogen atom or R.sup.5, are disclosed. These compounds are useful as intermediates for the synthesis of antibacterial agents.

Abstract: A 21-alkoxysteroid compound represented by the formula ##STR1## wherein R.sup.1 is an alkyl group having 1 to 4 carbon atoms or a methylthiomethyl group, R.sup.2 is an alkanoyl group having 2 to 7 carbon atoms, and a wavy line indicates the .alpha.- or .beta.-configuration has anti-inflammatory activity.

Abstract: A cephalosporin derivative represented by the general formula ##STR1## wherein R.sup.1 is a hydrogen atom or a protecting group of the amino group, R.sup.2 is a hydrogen atom or a protecting group of the hydroxyl group, R.sup.3 is a hydrogen atom or a protecting group of the carboxyl group, and R.sup.4 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and the non-toxic salts thereof are useful as antibacterial agents.

Abstract: A cephalosporin derivative represented by the formula ##STR1## wherein R.sup.1 is a hydrogen atom or a protecting group of the amino group, R.sup.2 is a hydrogen atom or a protecting group of the hydroxyl group, R.sup.3 is a hydrogen atom or a protecting group of the carboxyl group, X is a halogen atom, a cyano group, a vinyl group, a lower alkoxy group having 1 to 4 carbon atoms or a lower alkylthio group having 1 to 4 carbon atoms and n is an integer of 1 to 3, and a non-toxic salt thereof are useful as antibacterial agents for oral administration.

Abstract: Sulfonanilide compounds represented by the formula ##STR1## wherein R.sup.1 is a lower alkyl group or a trifluoromethyl group, R.sup.2 is a cycloalkylidenemethyl group, a group of the formula --A--R.sup.3 (wherein A is an oxygen atom, a sulfur atom, a sulfynyl group or a sulfinyl group and R.sup.3 is a cycloalkyl group having 5-8 carbon atoms; a cycloalkyl group having 5-8 carbon atoms substituted by one or two of a lower alkyl group, an oxo group, a hydroxyl group or a methanesulfonyloxy group, a tetrahydropyranyl group; a tetrahydrothiopyranyl group; or a 1-methyl-piperidyl group) or a group of the formula --B--R.sup.4 (wherein B is a carbonyl group, a hydroxymethylene group or a methylene group, R.sup.4 is a cycloalkyl group having 5-8 carbon atoms) and the pharmaceutically acceptable salts thereof have anti-inflammatory activity.

Abstract: A 21-substituted thiosteroid represented by the general formula ##STR1## wherein R.sup.1 represents an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 or 6 carbon atoms, a phenyl group, or a benzyl group which may have a substituent on the benzene ring,R.sup.2 represents an alkanoyl group having 2 to 6 carbon atoms,R.sup.3 represents a hydrogen atom or a methyl group,X represents a hydrogen or halogen atom, andthe dotted line between 1- and 2-positions represents an optional bond. These compounds are useful an anti-inflammatory agents.

Abstract: Cephalosporin derivatives represented by the general formula ##STR1## wherein R is a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms, R' is a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 or 6 carbon atoms or a benzyl group, or R and R' together with the nitrogen atom to which they are attached form a tetrahydropyridinyl group, a morpholinyl group or pyrroridinyl group, and the non-toxic salts thereof are disclosed. These compounds are useful as antibacterial agents.

Abstract: Erythromycin derivatives represented by the general formula ##STR1## wherein R.sup.1 is a hydrogen atom or a methyl group, R.sup.2 is a hydrogen atom or a hydroxy group, R.sup.3 is a hydrogen atom, a lower alkanoyl group, an alkoxycarbonyl group or an alkylsuccinyl group, and the salts thereof are disclosed. These compounds have antibacterial activity.

Abstract: Cephalosporin derivatives represented by the general formula ##STR1## wherein X represents a halogen atom, a hydroxyl group, a cyano group, a trifluoromethyl group, an amino group, a lower alkylcarbonylamino group, a lower alkoxy group, a lower alkylthio group, a lower alkoxycarbonyl group, a carbamoyl group, a substituted carbamoyl group, a carbamoyloxy group, a lower alkylcarbonyl group, a lower alkenyl group, an ethynyl group, a thiocyanate group, an .alpha.-carboxyaminomethyl group, a phenyl group, a pyridinyl group or an aminothiazolyl group, and n is an integer of 1 to 3, and the non-toxic salts thereof, are disclosed. These compounds are useful as antibacterial agents.

Abstract: 2-Azetidione derivatives represented by the following formula ##STR1## wherein X is a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a hydroxyl group or a cyano group, l is 1 or 2, R.sup.1 is a lower alkyl group, a cycloalkyl group, a 1-naphthylmethyl group, an optionally substituted phenethyl group, an optionally substituted phenyl group, an optionally substituted benzyl group or a bis(alkoxycarbonyl)ethyl group, and R.sup.2 is a lower alkyl group, a lower alkoxy group, an amino group, an adamantyl group, a lower alkoxycarbonylmethyl group or an optionally substituted phenyl group, are disclosed. These compounds are useful as blood platelet aggregation inhibiting agents.

Abstract: Unsymmetrical 1,4-dihydropyridine-3,5-dicarboxylic acid diesters represented by the general formula ##STR1## wherein R.sup.1 and R.sup.2 are different and represent each a nitratoalkyl having 2 or 3 carbon atoms, are prepared from the corresponding acid monoester in the presence of an organic acid anhydride activating agent. These compounds are useful as therapeutic agents for cardiovascular disorders.

Abstract: Cephalosporin derivatives represented by the general formula ##STR1## Wherein X represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, an allyl group, a cycloalkyl group having 5 or 6 carbon atoms or a benzyl group, and the non-toxic salts thereof are disclosed. These compounds are useful as antibacterial agents.

Abstract: Novel benzo[.alpha.]phenazine derivatives of the formula ##STR1## wherein R.sup.1 is hydrogen, halogen, methyl, hydroxyl or alkoxy, R.sup.2 is --COOR.sup.5 (wherein R.sup.5 is hydrogen, straight or branched chain alkyl, cycloalkyl having 3-6 carbon atoms, benzyl or phenyl) or ##STR2## wherein R.sup.6 and R.sup.7 are the same or different and are each hydrogen or lower alkyl, or R.sup.6 and R.sup.7 together with the nitrogen atom to which they are attached form pyrrolidine or piperidine), R.sup.3 and R.sup.4 are the same or different and are each hydrogen or lower alkyl, and n is an integer of 2 or 3, and the salts thereof are disclosed. These compounds have antitumor activity in mammals.

Abstract: A novel 6-O-methylerythromycin A derivative represented by the formula ##STR1## and the salts thereof are disclosed. These compounds are useful as intermediates for preparation of 6-O-methylerythromycin A and useful as antibiotics.

Abstract: A method for the selective methylation of a hydroxy group at the 6-position of an erythromycin A derivative which comprises converting an erythromycin A derivative into an erythromycin A 9-oxime derivative, and reacting the resulting ethythromycin A 9-oxime derivative with an methylating agent.

Abstract: A method for the selective methylation of the hydroxy group at the 6-position of erythromycin A derivatives which comprises reacting a compound represented by the formula R-X (wherein R is a 2-alkenyl group, a benzyl group or a substituted benzyl group, and X is a halogen atom), reacting the resulting quaternary salt compound with a methylating agent, and then eliminating R groups of the resulting compound to give 6-O-methylerythromycin A 9-oxime, is disclosed.

Abstract: Benzoylpropionic acid derivatives represented by the general formula ##STR1## (wherein R.sup.1 represents a hydrogen atom, a lower alkyl group or a benzyl group, R.sup.2 represents a lower alkyl group or a phenyl group, X represents a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a phenoxy group or a halogenophenoxy group, and Y represents a hydrogen atom or a lower alkyl group). The compounds have immunomodulative function and are effective for treatment of diseases caused by abnormal immunofunction.

Abstract: 3-Benzoyl-2-mercaptopropionic acid derivatives represented by the general formula ##STR1## (wherein, X represents a hydrogen atom, a halogen atom, hydroxy group, a lower alkyl group or a lower alkoxy group, Y represents a hydrogen atom, a halogen atom, a lower alkyl group or a lower alkoxy group, Z represents a hydrogen atom or an acyl group, and R represents a hydrogen atom or a lower alkyl group). These compounds have immunomodulative function and are effective for the treatment of diseases caused by abnormal immunofunction.

Abstract: Erythromycin A derivatives represented by the general formula wherein R1 is a 2-alkenyl group having 3 to 15 carbon atoms, an arylmethyl group, or an arylmethyl group substituted by 1 to 3 of a halogen atom, an alkoxy group 1 to 4 carbon atoms, a nitro group or an alkoxycarbonyl group having 2 to 6 carbon atoms, R2 is a substituted silyl group and R3 is a hydrogen atom or R2, are disclosed. These compounds are useful as intermediates of the anti-bacterial agents.