Patent ID: 7192943

Claim:
A compound of the formula [I]: wherein R 1 is lower alkyl or hydroxy(lower)alkyl, and R 2 hydrogen or an amino protecting group selected from the group consisting of acyl, substituted or unsubstituted aryl(lower)alkylidene, and aryl(lower)alkyl, or R 1 and R 2 are bonded together and form lower alkylene; R 3 is -A-R 6 wherein A is a bond, —NHCO—(CH 2 CO) n —, wherein n is 0 or 1, lower alkylene, —NH—CO—CO—, or wherein Z 1 and Z 2 are independently —NHCO— or —CONH—, k, q and r are independently 0 or 1, s and t are independently an integer of 0 to 6, m and p are independently an integer of 0 to 6, and R 7 , R 8 , R 9 and R 10 independently amino, amino protected with acyl, substituted or unsubstituted aryl(lower)alkylidene, or aryl(lower)alkyl, guanidino, guanidino protected with acyl, substituted or unsubstituted aryl(lower)alkylidene, or aryl(lower)alkyl, amidino or amidino protected with acyl, substituted or unsubstituted aryl(lower)alkylidene, or aryl(lower)alkyl; R 4 is carboxy or esterified carboxy; and R 5 is amino or amino protected with acyl, substituted or unsubstituted aryl(lower)alkylidene, or aryl(lower)alkyl; or a pharmaceutically acceptable salt thereof.