Novel nitrogenated heterocyclic compound and salt thereof

A compound represented by the general formula:

• wherein the dashed line represents a single bond or a double bond;
• R1, R2, R3, R4 and R5 are the same or different and represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a formyl group, an amino group which may be protected or substituted, a lower alkyl, cycloalkyl, aryl, lower alkoxy, cycloalkyloxy, aralkyloxy, alkanoyl, ureido or monocyclic heterocyclic group which may be substituted or a group represented by the general formula -Q1-CONR7R8, -Q1-CO2R9 or -Q1-CN (wherein R7 and R8 are the same or different and represent a hydrogen atom, a lower alkyl, cycloalkyl, aralkyl, aryl, lower alkoxy, alkanesulfonyl or monocyclic heterocyclic group which may be substituted, or R7 and R8, together with the nitrogen atom to which they are attached, represent a cyclic amino group which may be substituted;
• R9 represents a hydrogen atom or a carboxyl protective group;
• Q1 represents a lower alkylene or lower alkenylene group which may be substituted, a lower oxyalkylene group which is attached to the ring via a terminal oxygen atom and which may be substituted or a bond);
• R6 represents a lower alkyl, aryl, monocyclic heterocyclic, bicyclic heterocyclic or tricyclic heterocyclic group which may be substituted;
• X1 represents a lower alkylene group which may be substituted with one or more groups selected from a hydroxyl and a carboxyl groups which may be protected, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower alkoxy group and an aryl group;
• X2 represents a lower alkylene, lower alkenylene or lower alkynylene group which may be substituted;
• X3 represents an oxygen atom, a sulfur atom, a sulfinyl group, a sulfonyl group, a group represented by the general formula NR10 (wherein R10 represents a hydrogen atom, a lower alkyl or lower alkynyl group which may be substituted or an imino protective group) or a bond;
• Y1 represents a group represented by the general formula
• (wherein R11, R11a, R24 and R24a are the same or different and represent a hydrogen atom, a halogen atom, a hydroxyl group, an amino, lower alkyl or lower alkoxy group which may be substituted, an oxo group or a group represented by the general formula -Q2-CONR14R15, -Q2-CO2R16 or -Q2-CN (wherein R14 and R15 are the same or different and represent a hydrogen atom, a lower alkyl, cycloalkyl, aralkyl, aryl, lower alkoxy, alkanesulfonyl or monocyclic heterocyclic group which may be substituted, or R14 and R15, together with the nitrogen atom to which they are attached, represent a cyclic amino group which may be substituted;
• R16 represents a hydrogen atom or a carboxyl protective group;
• Q2 represents a lower alkylene or lower alkenylene group which may be substituted, a lower oxyalkylene group which is attached to the ring via a terminal oxygen atom and which may be substituted or a bond);
• R12 and R12a are the same or different and represent a hydrogen atom, a lower alkyl or lower alkynyl group which may be substituted or an imino protective group;
• R13 represents a halogen atom, a hydroxyl group, an amino, lower alkyl or lower alkoxy group which may be substituted, an oxo group or a group represented by the general formula -Q3-CONR17R18, -Q3-CO2R19 or -Q3-CN (wherein R17 and R18 are the same or different and represent a hydrogen atom, a lower alkyl, cycloalkyl, aralkyl, aryl, lower alkoxy, alkanesulfonyl or monocyclic heterocyclic group which may be substituted, or R17 and R18, together with the nitrogen atom to which they are attached, represent a cyclic amino group which may be substituted;
• R19 represents a hydrogen atom or a carboxyl protective group;
• Q3 represents a lower alkylene or lower alkenylene group which may be substituted, a lower oxyalkylene group which is attached to the ring via a terminal oxygen atom and which may be substituted or a bond);
• or R11 and R24 together and R12a and R24 together represent a lower alkylene group which may be substituted);
• Z1 represents (1) when the dashed line represents a double bond, a nitrogen atom or a group represented by the general formula CR20 (wherein R20 represents a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a formyl group, an amino group which may be protected or substituted, a lower alkyl, cycloalkyl, aryl, lower alkoxy, cycloalkyloxy, aralkyloxy, alkanoyl, ureido or monocyclic heterocyclic group which may be substituted or a group represented by the general formula -Q4-CONR21R22, -Q4-CO2R23 or -Q4-CN (wherein R21 and R22 are the same or different and represent a hydrogen atom, a lower alkyl, cycloalkyl, aralkyl, aryl, lower alkoxy, alkanesulfonyl or monocyclic heterocyclic group which may be substituted, or R21 and R22, together with the nitrogen atom to which they are attached, represent a cyclic amino group which may be substituted;
• R23 represents a hydrogen atom or a carboxyl protective group;
• Q4 represents a lower alkylene or lower alkenylene group which may be substituted, a lower oxyalkylene group which is attached to the ring via a terminal oxygen atom and which may be substituted or a bond));
• (2) when the dashed line represents a single bond, a group represented by the general formula NR40 (wherein R40 represents a hydrogen atom, a hydroxyl group, a lower alkyl, cycloalkyl, lower alkenyl, lower alkynyl, aryl, lower alkoxy, cycloalkyloxy or monocyclic heterocyclic group which may be substituted or an imino protective group) or a group represented by the general formula CHR20 (wherein R20 is as defined above), or a salt thereof.