Abstract: An amidine compound represented by formula (I) (wherein A1 represents a nitrogen atom or a group represented by formula CR6; A2 and A3 are the same as or different from each other and independently represent a nitrogen atom or a group represented by formula CH; R1 represents an aryl group which may be substituted by 1 to 5 substituents independently selected from a substituent group (2) or the like; R2 and R3 are the same as or different from each other and independently represent a hydrogen atom, a halogen atom, a C1-6 alkyl group, a C1-6 haloalkyl group or a C1-6 alkoxy group; and R4 and R5 are the same as or different from each other and independently represent a hydrogen atom, a C1-6 haloalkyl group, a C1-6 alkyl group or the like) or a salt thereof. The compound is useful as an anti-fungal agent.

Abstract: The purpose of the present invention is to provide a novel compound which has an anti-fungal activity on pathogenic fungi including fungi belonging to the genus Candida, the genus Aspergillus and the genus Trichophyton and is useful as a medicinal agent.

Abstract: An erythromycin A derivative represented by Formula wherein R1 is a group represented by the formula: a group represented by the formula: (c) pyridylacetyl, (d) cycloalkylmethyl or (e) 1,2 bis-(ethoxycarbonyl)vinyl, R2 is the same group as defined for R1, hydrogen, alkyl, alkanoyl, alkoxycarbonyl, R1 and R2 together may form ═CH—R14, or R1 and R2 together with the nitrogen atom to which they are attached may form: R3 is hydrogen, alkyl or cinnamyl, R4 is hydrogen, acetyl, ethylsuccinyl or nicotinoyl, A is —OC(═O)—R17, —OC(═O)—CH2—R17, —OC(═O)—NH—R17, —O—R17 or —OC(═O)—O—R17, and R5 and R6 are each hydrogen or alkyl.

Abstract: An erythromycin A derivative represented by the formula: wherein n is an integer of from 1 to 8, R1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R2 is a pyridylmethyl group, a quinolylmethyl group, a pyridylsulfonyl group or quinolylsulfonyl group, R3 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a cinnamyl group, R4 is a cladinosyloxy group or a group represented by the formula: wherein m is 0 or 1, R5 is a pyridyl group, a quinolyl group, a phenyl group, a phenyl group substituted with one, two or three members selected from alkyl groups having 1 to 6 carbon atoms, a nitro group, alkoxy groups having 1 to 3 carbon atoms and halogen atoms, or a pyridyl or quinolyl group substituted with one or two members selected from alkyl groups having 1 to 6 carbon atoms, a nitro group, alkoxy groups having 1 to 3 carbon atoms and halogen atoms; or a pharmaceutically acceptable salt thereof.

Abstract: An erythromycin A derivative represented by Formula (I): ##STR1## (wherein n is an integer of 2 to 4, R.sup.1 is a pyridylmethyl group, a furylmethyl group, a thienylmethyl group, a quinolylmethyl group or a benzyl group having 1 to 3 substitutents selected from the group consisting of an alkyl group having 1 to 5 carbon atoms, a nitro group, an alkoxy group having 1 to 5 carbon atoms, an amino group and an amino group substituted by 1 or 2 alkyl groups having 1 to 5 carbon atoms, R.sup.2 is the same group as defined for R.sup.1, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an acetyl group or a pyridylacetyl group, and R.sup.3 is an alkyl group having 1 to 5 carbon atoms or a cinnamyl group) or a pharmaceutically acceptable salt thereof has a strong antibacterial activity against not only known erythromycin-sensitive bacteria but also erythromycin-resistant bacteria and Haemophilus influenzae.

Abstract: An erythromycin A derivative represented by Formula (I): ##STR1## wherein R is a pyridyl group, a quinolyl group, a nitrophenyl group or a methoxyphenyl group, or a pharmaceutically acceptable salt thereof has a strong antibacterial activity not only against erythromycin-sensitive bacteria but also against certain erythromycin-resistant bacteria and Haemophilus influenzae.

Abstract: An erythromycin A derivative represented by the formula (I): ##STR1## ?wherein R.sup.1 is a group represented by the formula: --OCOCH.sub.2 Y (wherein Y is a pyridyl group, a quinolyl group, a p-nitrophenyl group or a group represented by the formula: --NR.sup.4 R.sup.5 (wherein R.sup.4 and R.sup.5 may be the same or different, and are each a hydrogen atom, a methyl group, a pyridylmethyl, a quinolylmethyl group or a benzyloxycarbonyl group)) or a cladinosyloxy group, R.sup.2 is a hydrogen atom, or R.sup.1 and R.sup.2 together form an oxo group, R.sup.3 is a hydrogen atom, an acetyl group, an ethylsuccinyl group or a nicotinoyl group! or a pharmaceutically acceptable salt thereof has a strong antibacterial activity against not only Gram-positive bacteria but also some Gram-negative bacteria, in particular, Haemophilus influenzae which is a serious factor of infectious diseases in the respiratory organs.