CEPHEM-VERBINDUNGEN

摘要

The present invention relates to a compound of the formula [I]: wherein R¹ is lower alkyl or hydroxy(lower)alkyl, and R² is hydrogen or amino protecting group, or R¹ and R² are bonded together and form lower alkylene; R is -A-R⁶ wherein A is bond, -NHCO-(CH₂CO)_n-, lower alkylene, -NH-CO-CO- or the like, and R⁶ is wherein R⁷, R⁸, R⁹ and R¹⁰ are independently amino, guanidino, amidino or the like; R⁴ is carboxy or protected carboxy; and R⁵ is amino or protected amino, or a pharmaceutically acceptable salt thereof, a process for preparing a compound of the formula [I], and a pharmaceutical composition comprising a compound of the formula [I] in admixture with a pharmaceutically acceptable carrier.