| abstract |
ABSTRACT OF THE DISCLOSURE A compound represented by the following formula: wherein R1 represents a hydrogen atom or a hydroxyl group, R2 represents a group of the formula -CH2NO2, or in which A represents a group of the formula or in which R4 represents a hydrogen atom or an alkoxycarbonyl group, R5 represents a phenyl, alkoxycarbonyl or alkanoyloxymethyl group, R6 represents an alkyl group and R7 represents a phenyl, naphthyl, pyridyl, furyl or thienyl group; and R3 represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group, and a process for production thereof. The compounds have excellent antibacterial activity against various pathogenic microorganisms and have the ability to increase the antibacterial activity of known .beta.-lactam antibiotics against .beta.-lactamase-producing microorganisms. |